Talk:Pixel/Archive 1
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Archive 1 |
old junk not in a section
and in english this all means?? ÉÍREman 16:16 May 6, 2003 (UTC)
- Indeed. I've had a go at a clearer intro, but I'm not happy with it. I hope someone else can improve it. The problem is that it's very hard to say what a pixel is: screen element; printing; part of a digital image. Though in the last case we're strictly dealing with texels; but only the 3D gaming industry makes that distinction AFAIK -- Tarquin 16:30 May 6, 2003 (UTC)
I'm a historian whole technical skills are such that if I change a light bulb I am likely to black out all of North Dublin, so I am afraid the article went completely over my head, but then anything technical does anyway. But then I suppose people people are are technologically literate might find the stuff I write on historiography or royal naming procedures over their heads too. Each to his or her own! I notice BTW that an earlier version mentioned a mac's 'thousands' and 'millions' in term of screen colours, so I learned something about what that actually means on my eMac. Except that that info was culled from later versions!!! I decided to check just what the hell pixel was because I bought a new digital camera that uses 3.2 million pixels so I was hoping to find out what it was I had bought. The joys of being technologically illiterate! ÉÍREman 19:44 May 6, 2003 (UTC)
Very nice picture, Tarquin! I'm even willing to overlook the fact that the lines connect the wrong corners. ;) -- John Owens 21:41 May 6, 2003 (UTC)
- dang! I'll fix it later. -- Tarquin (boy am I glad I always keep my layered photoshop documents!)
I'm a bit put off by: " This can be expressed as a single total,", because it seems to me the single number is a product, not a total... but I can't see how to change it without making it too complicated -- Tarquin 21:48 May 6, 2003 (UTC)
- Is this the bit that now reads "For depths larger than 8 bits, the number is the total of the three RGB ..."? If so, I agree that total is the wrong word, but describing it in a way that a non computer-literate person will immediately grasp is difficult. Perhaps something along the lines of "For depths larger than 8 bits, the bits themselves are divided into three seperate values that describe the intensities of the red, green, and blue components of the desired colour.", since the values are not really either a product or total. Lumpbucket 01:08 August 12, 2003 (BST)
I added a section on what a digital camera "megapixel" REALLY is, and also added sections for pels and sub-pixels.
On the digicam megapixel subject, I sent an email to the apparent author of http://megamyth.homestead.com, asking him to contribute to the subject. Scott McNay 07:45, 2004 Feb 8 (UTC)
On another subject, can someone clarify several issues? I'd like to know:
- whether a "dot pitch" is the same as the pixel size, as loudly implied by this article, and not clarified at all by the dot pitch article?
- how "native resolution" (often seen in relation to LCDs) relates.
- whether "native resolution" applies to CRTs or not (which is implied by this article in the sub-pixel section), at least for horizontal resolution.
- How CRTs and LCDs display different horizontal resolutions when they have embedded color masks, and ditto for vertical resolution for LCDs.
Scott McNay 07:45, 2004 Feb 8 (UTC)
- Sigh ... I just tried editing the relevant section to put in a couple paragraphs about this... Got an 'edit conflict error'... seems the whole SECTION was deleted wholescale, and I was dumb enough to not copy & paste what I'd written into notepad before whacking "submit". Time to hit the history page and find out WTF is going on, if it's just a vandal or if it's heavy handed editing. I recognise my stuff needs editing, as I'm not a professional writer, but I do know enough of my beans when it comes down to dot pitch vs lcd pixel size, what typical (TCO 99 standards, even!) LCD resolutions are vs size (unlike the unrealistically coarse examples given) to be able to contribute at least the raw materials in some kind of understandable english. Chopping the entire thing seems a little rough, particularly as having scanned this talk page I can't see any suggestions/call for votes/etc on such 82.46.180.56 (talk) 16:09, 2 April 2008 (UTC)
Ok, looks like everything's been explained, and it all makes sense to me now; just have to clean up a bit now. Scott McNay 01:30, 2004 Feb 14 (UTC)
To do:
- Find or make a picture showing how sub-pixel font rendering (SPFR) helps. Put it on appropriate page
- Add mention on appropriate page of Apple (?) using SPFR on Apple II (?)
- Factor Pixel page so that image pixels are discussed separately from monitor pixels, ec. Right now, kinda mixed up.
- Find or make a picture showing pixel geometry for a typical digital camera. Mention that a digicam triad is quite large, due to having more green pixels than red or blue pixels. May want to un-redirect megapixel page.
- Clarify that pixels and sub-pixels are logical constructs, and triads and dots are physical constructs.
- Can someone clarify that SPFR really requires that the SPFR routine know the LCD monitor's native resolution, and/or works best when monitor is set to native resolution?
- Can someone explain how SPFR works on CRTs (see Apple II reference), when the image's location on the screen can vary from moment to moment?
Scott McNay 02:29, 2004 Feb 14 (UTC)
More info about SPFR available at http://www.grc.com/cleartype.htm
- Considering that apparently some monitors (CRTs?) have vertical stripes, that would imply that diagonal dot pitch measurement simply doesn't apply to them, since verical resolution would be limited only by the number of scan lines that can be squeezed onto the screen. Comment?
- Here is an example of a great pixel website Commerce.co.uk
- Update pixel geometry to mention triads instead of pixels
- Merge triad and pixel geometry pages? Could edit/replace pictures to show both the geometry and the outline of a triad on the pictures
- Update triad to clarify that sub-pixel is not the same as a triad
Scott McNay 03:01, 2004 Feb 14 (UTC)
As i have always known and was taught, dot pitch IS a diagonal measurement. It is the measurement of the shortest distance between 2 like-colored phosphor dots (what someone started terming sub-pixel). Since a triad is made up of the 3 color dots in a triangle formation, as they are placed on the screen the measurement of dot pitch is always diagonal.
Dot pitch simply doesnt apply to an LCD screen, since LCD does not use phosphor dots, but rather a square made up of 3 tall rectangles in the primary colors. Sorry i do not know the term for that element in an LCD screen.
Im sure someone can clarify it more in the article.
- Enos Shenk 22:37, 14 Feb 2004 (UTC)
Does dot pich apply to Trinitron tubes? They have stripes also, I believe, and I don't have one to look at, but I would guess that the stripes are solid, not broken, meaning no vertical component.
So now the question is, are some companies actually reporting incorrect values for dot pitch? The first link below has some discussion on the subject.
- http://www.pctechguide.com/06crtmon.htm (starting with the dot pitch section)
- http://www.pctechguide.com/07panels.htm
- http://entertainment.howstuffworks.com/tv.htm
- http://computer.howstuffworks.com/monitor.htm (see page monitor4)
- http://computer.howstuffworks.com/question401.htm (none of the links at the end of the article are good)
Add note that SPFR is sometimes called "pixel borrowing".
After reading Wiki, HSW seems, well, mildly biased and incredulous. :)
(Forgot to put my sig above.)
Ok, I will edit (unless someone else does it first; I have some cleaning up to do around here, and headed out for a few hours with a friend this afternoon) the various articles to indicate:
- CRTs are analog and LCDs are digital, in the sense that on an LCD, a specific pixel can be guaranteed to correspond to a triad, whereas on CRTs, a pixel is most likely to land on varying parts of two triads (a pic showing this would be nice). Would it be accurate to say "Because of this vagueness, "native resolution" does not apply well to CRTs"?
- "sub-pixel" refers to digital displays
- "phosphor dot" refers to analog displays
- stripe pitch (sometimes called dot pitch) is a horizontal measurement for Trinitron CRTs
- dot pitch is a diagonal measurement for non-Trinitron CRT screens. For non-digital displays, the term is rather vague.
- SPFR only applies to digital displays
- SPFR seems to help on analog displays because it is an anti-alising method but standard methods give beter results for non-digital displays.
- Add an image for slotted mask. [1] shows the dot pitch being measured horizonally in this case, which I think is likely part of the cause of the "some companies measure wrong" issue.
- Incorporate other dot pitch caveats from [2].
- Etc.
Is someone else here better than I am with making pictures? I just have MS Paint, here... Scott McNay 17:47, 2004 Feb 15 (UTC)
Pixelated picture... not really
The picture at the top of the page that shows the keyboard pixelated... you can't really make out individual pixels, as the article to the left says. The three below it, though, do have good quality, as you can make out individual pixels. ==New pixel article==
New pixel article
I'm starting the new article at talk:Pixel/new. The idea about tiles in mosaic came from Fuzheado. Scott McNay 06:16, 2004 Feb 18 (UTC)
Difference between px, pt, em
Is there an article which covers the difference between px, pt, and em measurements? These are used in drawing programs, css, etc. A single article that ties them all together would be nice. (also pica, ex, etc.)
css definitions: http://css.weblogsinc.com/entry/1234000933032102/
SVG definitions: http://www.xml.com/pub/a/2001/03/21/svg.html (what i was specifically looking for)
how it relates to font size in pt, how it relates to DPI, etc., etc.
- Omegatron 16:26, Apr 6, 2005 (UTC)
Rollback
I meant to edit a local version of this page, but instead edited the Wikipedia version. Is there a way to rollback to the previous version?
This article needs a lot of work
This article contains a large amount of pseudo-erudition caused by layer on layer of pedantic corrections. Some of the pedants knew something about image processing. Unfortunately, most didn't. It now desperately needs editing by actual image-processing experts, followed by extensive copyediting to remove redundancy and simplify flow. -- Karada 20:18, 22 Jun 2005 (UTC)
- On a quick read, I found a lot of good stuff here. I hope we don't get carried away with style and whatever and reduce the meat in the article. I appreciated what I read. May give it a critcal read later.
Phil talk 14:47, 14 September 2005 (UTC)
- I've worked it over some, from a position of knowledge. I hope my changes don't fall into the overly pendantic category, but that's always a danger when trying to make sloppy stuff be correct. Dicklyon 03:10, 25 May 2006 (UTC)
picture element versus picture cell
which is correct? the article states element, but i have always heard cell - mastodon 22:56, 22 April 2006 (UTC)
- Most early uses of pixel (1965-1980) specifically said it meant picture element. The notable exceptions that I am aware of were in publications and patent applications out of Xerox Palo Alto Research Center, 1976 to 1982, which used picture cell. For example, see US4034343: Optical character recognition system, by Michael Wilmer, filed 1976-10-01. But since you weren't born yet, maybe that's not where you heard it. Your pixel historian, Dicklyon 03:07, 25 May 2006 (UTC)
Coinage
Who coined the term? Does anyone know? I know a guy who thinks he may have coined it in a naval document in 1973 or so. Jfingers88 01:37, 15 June 2006 (UTC)
- The earliest known publications of pixel are by Frederic C. Billingsley in 1965; but he did not coin it, nor did Keith McFarland, subcontractor from whom Fred leaned the term. We don't know who coined it. See the last external link in the pixel article. Dicklyon 02:06, 15 June 2006 (UTC)
Subpixels -- new images
What's the story with the new images? I notice one is alternating black and white pixels, while the other is alternating green and magenta. Both look gray. So what does this have to do with subpixels, and why is the first one repeated, and then the pair are shown combined, and there are not words about the figure or its point. Can someone please explain or fix? Dicklyon 05:20, 1 July 2006 (UTC)
At least on my display the first two look different from each other. Maybe you have got different equipment/drivers. The pixels on the image file, show up differently on display as the software tries to fit 100*100px on the image to 98*98px or 97*97px on display. Doesn't the 100/98 and 100/97 -ratios force the display driver handle subpixels? I'm not sure if this is the right place for these. Some of the software I have, show the combination as gray with a magenta line in the middle. Also, Image:Resolution illustration.png on image resolution -article might be a better example. Dreg743 06:20, 2 July 2006 (UTC)
- The drivers probably have nothing to do with it. The web browser scales the image, and it's usually (at least on Mozilla/Firefox) a quick and simple nearest-neighbour algorithm. Safari and/or Opera might do a higher-quality resampling of the image. So relying on the thumbnail width to force "subpixels" is not going to work. Different web browsers do things differently, it's how the web works. Just what exactly are you trying to show with these images? Imroy 11:16, 2 July 2006 (UTC)
- Well, the difference of one pixel changed the appearance of the image (on my (browser) display. On my system, they have one light grey circle (98px) and 4 light grey circles (97px) on dark grey, even though the 'image' is what it is. Just thought this was an universal fenomenon. At least I know now that that those images aren't always like that. Thanks for the response. removing images.... Notgray.GIF and Stillnotgray.png ... Dreg743 12:24, 2 July 2006 (UTC)
pixel size.
can pixels be different sizes? or are they a physical unit of measurement (distance).
- They can be arbitrary sizes, but within a given system are usually of a constant size. When you change the display resolution on a CRT, you change the pixel size. Camera pixel sizes can sometimes be changed by an integer factor, by aggregating several pixels into one. In an image file, pixels have no definite size, but a size can be attributed to them via metadata (for example, a tag that says how many pixels per inch); in that sense, the image pixel size is easy to change. Dicklyon 22:41, 4 July 2006 (UTC)
- thanks... so, for example, on a standard TV, all else being the same.. would a 40" TV have 4 times the number pixels of a 20" TV?
- No, not at all. With a TV, the number of pixels is determined by the video source. The screen doesn't have pixels of its own, and even if it did, bigger wouldn't mean more of them. With LCD and plasma screens, you can get pixels associated with the screen, but again the screen size has little to do with number. There are various sizes, with names like EDTV that correlate with numbers of pixels, but I'm no expert on that. Dicklyon 18:51, 6 July 2006 (UTC)
- The resolution of the image indicates the number of pixels. TV is generally only one resolution, no matter how large or small the TV is; a small TV which will fit in your hand is the same resolution, and therefore the sme number of pixels, as a large console or projection TV. You only change the resolution when you change to a different type of TV, such as from NTSC to HDTV. --Scott McNay 04:26, 28 August 2006 (UTC)
- In addition to the original question: a pixel is simply the smallest individual unit in a display system that can change it's color. A pixel usually consists of three light sources: red, blue and green; by varying their intensity you can change the color of the total pixel. In other words; a "pixel" doesn't necessarily have a fixed sixe. For instance: you could make a video wall consisting of LED-panels. Then a pixel would be a group of 3 LED's: red, blue and green; naturally such a 'pixel' is much larger then a pixel in a Television screen or a TFT screen. RagingR2 13:05, 10 April 2007 (UTC)
New image removed
I don't understand this image. Can someone explain, maybe fix it or make a better caption? What is the relationship between the top row images and the bottom row, which are labeled only by different X values? Dicklyon 18:09, 27 August 2006 (UTC)
The bottom set isn't labelled well and/or properly. The top two look like what you'd see logically, and the bottom two show what you see physically, when looking closely at a flatpanel monitor or a Trinitron-style CRT. --Scott McNay 03:10, 28 August 2006 (UTC)
Opinions, Sigma/Foveon Hype Removed
Most of the section on "Megapixel" had almost nothing to do with the topic at hand, and can be found in the sections on CCDs and digital cameras. In addition, an encyclopedia entry isn't really the place to continue the Foveon vs. Bayer Pattern sensor debate. As most of the section was extraneous, I removed everything but the simple definition. ElGordo 23:32, 27 September 2006 (UTC)
- I restored most of it, but took out some of the informal stuff like "marketing ploit". I don't think the statements about Foveon here are either hype or debatable; it just explains how they count pixels in both types of sensors, which is easily verifiable. Dicklyon 23:40, 27 September 2006 (UTC)
- I think my issue with it has more to do with the question that was on my mind... in an encyclopedia entry for pixel, which is a simple term, do I expect to find a full explanation of pattern array interpolation vs. stacked sensor, or just a general definition of pixel with perhaps a few "see also's" to topics briefly covered. The topic as written now is verifiable and true, but it isn't why someone typed the word pixel into wikipedia. ElGordo
- Not everyone is there for the same reason, I suspect. It doesn't seem out of place to explain the derived term "megapixel" as commonly applied to cameras, without having to read articles on sensors, etc. Similarly, the application of "pixel" and "subpixel" to displays, etc., is explained, and rightly so, in this article. Dicklyon 23:58, 27 September 2006 (UTC)
- I think my issue with it has more to do with the question that was on my mind... in an encyclopedia entry for pixel, which is a simple term, do I expect to find a full explanation of pattern array interpolation vs. stacked sensor, or just a general definition of pixel with perhaps a few "see also's" to topics briefly covered. The topic as written now is verifiable and true, but it isn't why someone typed the word pixel into wikipedia. ElGordo
I have also shifted the order of terms in the section below this, as the VGA/SVGA etc. names were created to define the resolutions listed and by standard format should be listed first on the line, not the other way around. All information retained and the topics were linked to the appropriate sections about them.ElGordo
I have to say...
I'm a real technophile, but I read this article several times to no avail. I always thought that the pixel was just that little dot that is multiple colors... Now it's trying to say that it's something positively different? Hmm... I think this could be revised so the people who haven't majored in English, Latin, and Arabic can understand it :) ~ Theta :D 06:57, 14 November 2006 (UTC)
- If that's all you thought it was, then you learned something, yes? I missed the Arabic part. Dicklyon 06:37, 19 November 2006 (UTC)
Megapixel section
The information I added has been removed (Dicklyon : revert long-winded not-quite-right stuff specific to 4:3 cameras with non-real numbers). OK it might have been a bit long winded, but could it not have been edited instead of completely removed. I think the section could do with some more information. I'm not sure which bit was not-quite-right.
It was specific to 4:3 cameras, but this includes the majority of consumer digital cameras and video camera sensors. Maybe the calculations were not needed, but I find it useful to be able to calculate the horizontal and vertical pixels counts given any Megapixel value. The numbers in the table gave an exact number of megapixels (unless I am mistaken 1MP is 10^6 and not 2^20 as in the computer Mega). I agree that these mathematical figures do not correspond to actual image sensor horizontal and vertical pixel counts, but it does not make it incorrect. The image sensors used have different pixel counts depending on the manufacturer.
I thought that this comment was useful, as I believe it is a common misconception : 'Note that a 6 megapixel image does not have double the number of horizontal pixels of a 3 megapixel image. It is not until 12 megapixels that the number doubles.'
Andy, 19 November 2006
- OK, maybe I overdid it, but it looked too hard to fix. Of course, it can be recovered and reworked any time you or someone is motivated to do so. Being specific to 4:3 bothered me, since DSLRs are usually 3:2 and there are other aspect ratios as well; if you're going to put equations, try to be more general. The main thing that was not quite right was the list of sizes, which didn't correspond to any actual camera or sensor sizes of the stated megapixel ratings, and would therefore just confuse people who were trying to compare with known facts. The stated relationships were also not applicable to a 3D pixel arrangement (rows x cols x layers) like in the Foveon sensors, nor to the pixel arrangements in SuperCCD sensors. And finally, it was not really obvious why one would generally need to go from megapixels to numbers of rows and columns; what for? It's hard to be sufficiently general there, since aspect ratios and organization and roundoff error are so variable; and those numbers are usually provided explicitly with any camera. Using two sentences to point out that twice as many rows and columns means four times as many pixels also seemed like overkill, though it's a good point. But is any of this needed to explain what megapixel means? Why it is in the pixel article if it's about particular digicam organizations? Seems like it would go better in a digicam article. Dicklyon 06:36, 19 November 2006 (UTC)
- Dicklyon, in answer to your question: why would anyone want to go from megapixel to high/width and vice versa? Well, I do so on a regular basis, since when I am editing images on my computer I'm more used to thinking in terms of hight/width than in Megapixels. Also, hight/width is more informative since a number of "Megapixels" only tells you the total number of pixels (duh) and not the dimensions. Unless you also specify a ratio of course, because then you can calculate it yourself. As a matter of fact, I've been thinking about adding something like a formula for that too; the same thing that Andy was appearantly concerned with. The thing I had in mind was something like this:
If
- x = image width
- y = image hight
- z = area (total number of pixels)
- r = image size ratio
Then
- z = x*y
- r = y/x
- x = y/r or (z/r)½
- y = x*r or (z*r)½
(sorry, don't know how to type a square root sign) So that you could calculate any of the variables x,y,z,r if you know at least 2 of the others. For instance, if you only know the number of megapixels and a ratio (for instance: 4/3 or 3/2) then you can instantly calculate the width and/or hight without opening the image on your computer and reading the width/hight from the information that your picture viewer gives you. Let me know if anyone else thinks this is useful information. Greetings, RagingR2 13:17, 10 April 2007 (UTC)
More etymology
I removed this interesting contribution:
- The concept of digital still photography was conceived by Eugene F. Lally of the Jet Propulsion Laboratory/California Institute of Technology. Lally propopsed an on board all-optical guidance system for manned planetary missions. His paper "Mosaic Guidance for Interplanetary Travel" was published in 1961 at the annual American Rocket Society convention. The concept used an array of tiny light sensors in a mosaic pattern with each element refered to as a mosaic element that formed an image sensor. The sensor would record star and planet positions during transit for navigation purposes and when near an approaching planet would provide additional stadiametric information for guidance purposes of the astronauts onboard.
This is fascinating, and I'd love to hear more about it. If there's a verfiable source, that would be good to know. But even if there is, how does it relate to pixel etymology? The concept of digital still photography predates that in a lot of image coding work in the 1950s, doesn't it? Dicklyon 03:09, 2 December 2006 (UTC)
Mr. Dicklyon: The "mosaic element", later to be called "pixel" was historically first used to describe the concept of recording light for still image capture. It was a small light sensor, one of many that were grouped together in a large number to form a mosaic image plane for navigational use on manned spacecraft. It was described in the paper of 1961, "Mosaic Guidance for Interplanetary Travel" from JPL. I have a copy of that paper. It is part of the history of how digital photography began and was presented at an annual meeting and published in their magazine "Astronautics". In the trade, this paper has been accepted as the initial disclosure of still digital photography as it first described the components needed. I would think it made sense to preserve this interesting piece of the Space program and the history of photography. E. Lally
- I think it makes sense, too. I'd love to have a copy of it. Can you email me dicklyon at acm dot org please? Dicklyon 04:07, 2 December 2006 (UTC)
Merge from picture element
I just found this little-editted article on picture element that should really be a redirect to here. It might have some good content worth merging in, but I haven't looked for it yet. Support or oppose? Dicklyon 04:35, 14 December 2006 (UTC)
Finding no oppostion or help, I converted it to a redirect. Here's the entire text of it (with headings demoted) in case there are bits anyone wants to incorporate into pixel:
Picture element
This is the original and proper name for the unit of resolution in visual display units (VDUs). They are now referred to as 'pixels', however this is merely a contraction of the phrase 'picture element'. A computer monitor with a resolution of 1280x1024 has 1280 picture elements (or pixels) horizontally, and 1024 vertically. A higher resolution means more detailed images can be displayed on the screen due to the fact there are more pixels, therefore monitors supporting higher resolutions are usually more expensive.
Pixel colours
A pixel is further defined by the display device colour-depth. This is a definition of the ability for a pixel to display a range of colours, or grey shades or simply to be on or off (white or black). Usually expressed in digital bits, displays operate in a specific 'Bits-Per-Pixel' (BPP) mode indicating the amount of computer bits used in all pixels on the display. In early graphical VDU displays, there was simply one bit for every pixel. The display was said to be monochrome, or black and white. Over time, with the advent of more capable display electronics, we now have 16, 24 or even 32 bits per pixel. The more information (BPP) we use for each pixel, the better a reproduction of colour in individual pixels we have.
The easiest example of this can be described with a 24 bit pixel. The primary colours of light - red, green and blue, can easily be divided into 24 bits, giving eight bits for red, eight for green and eight for blue. Eight digital bits, each being a 0 or 1 gives a total of 256 (2 to the power of 8) possible variations of each primary colour. Three primary colours times 256 (256 x 256 x 256) gives you a total 'colour palette' of 16,777,216 individual colours that any pixel can be at any one time on the display.
Digital storage of picture elements
Display devices represent the colour of a pixel using exactly that - values from 0 to 255 (256 in all) for red, green and blue 'components' of the pixel (if the display is operating in 24bpp mode). A complete 1280 x 1024 pixel screen, being made up of three bytes for every pixel, would mean we need to store 3,932,160 bytes, or just under 4 Megabytes, just for one screen.
For older display hardware that was not as capable, we did not have the luxury of storing 4Mb for the screen, so instead we used a palettised display. Palletising a screen involves not simply granting each pixel an ablility to display its own colour, but instead to represent each pixel with index within a separate table of colours, called a palette.
A common palettised arrangement was an 8-bit palettised display. Each pixel is not an individual colour, but instead is an 8-bit number (256). This number is used as a 'lookup' to the palette table. The table will also be 256 'rows', each row would contain a full representation of a particular colour. So if row one contains light purple, row two contains dark brown, row three contains bright orange, etc, a particular pixel would be able to point to one of these colours, and hence BE that colour.
This was usually fully handled by the display hardware in the computer system and so would operate quickly. The upside - less memory storage for each display, since each pixel would only be one byte, a 1280 x 1024 screen would take up 1,310,720, or 1.3Mb plus a very small palette table (24 bpp = 3 bytes times 256 rows = 768 bytes for the palette table). The downside - The whole display would only be able to show colours out of 256 different pre-defined colours at one time. This usually resulted in less than perfect representations of photographs and other high quality graphics, but was nonetheless effective and worthwhile. In practise though, older display hardware wouldn't be able to show 1280 x 1024 pixels, but more likely at 640 x 480 or 800 x 600 (480,768, or 480KB). A far more practical proposition given the high costs of display memory in the 80s and early 90s.
Palettised picture files
.GIF (Graphics Interchange Format) files are stored in a similar palettised fashion. If a GIF file were displayed occupying the whole screen of a modern full colour computer display, you would see similar poorer colour reproduction than that offered in other full colour image formats, such as .JPG.
- JPG doesn't really store pixels per-se... it keeps a compressed wave function instead (as I understand it, anyway), the reason for the distortion and detail loss at high compression factors. Also, it's colour resolution is one-quarter (half vertical + half horizontal) that of luminance, so even if it was keeping discrete digital pixels, they wouldn't each truly be assigned a full colour value each; instead they'd have a particular brightness, with the colour smeared between each square group of 4.
- Plus, GIF is arguably contemporary to 'modern' display layouts - we reached regular SVGA thru UXGA resolutions before video cards could handle true colour rendering at these sizes. I have a few GIF format wallpapers stashed in an old archive backup somewhere at XGA rez - the best size for working on our old 486 (then early pentium) PC with it's 15-inch monitor, but only in 256 colour mode as the card couldn't stand anything higher (or 16 colours at 1280x1024)... a resolution I'm STILL using today (12-inch laptop, common 14/15-inch LCDs), but in ubiquitous true-colour (and could even have done at the time with enough money, as a relative had an expensive Matrox 4mb card that could reach 24 bit at 1280x960!). Could still use the GIFs... they'd look quite good, as they were both chosen for suitability and tuned carefully in the colour reduction process. In fact, they'd probably look better, as they wouldn't suffer pallete distortion when using a colour-hungry application! 82.46.180.56 (talk) 14:51, 2 April 2008 (UTC)
- You're responding to an old very-flawed article that got replaced, not to a talk comment or anything currently relevant. Dicklyon (talk) 14:55, 2 April 2008 (UTC)
- Excuse me, I'm sure :) I had no idea. There was no date on the comment I replied to. Never mind, either way...
- Also, who's just gone and deleted the WHOLE SECTION I was editing? I see no 'talk' for that in here. In fact it almost seems the talk section i was going to put an 'Ah! Thanks for reminding me of that point, I went and added/updated that section, is it any good?' note into has vanished :/ (sizes, etc). So much so that when I pressed "back" to try and retrieve what I'd typed, the whole edit box had cleared. Gah. (Again, not too bothered, just momentarily put out cuz I spent 15+ minutes typing the main stuff, doing the calculations, tidying all the formatting etc only for it to fall in the toilet) 82.46.180.56 (talk) 16:04, 2 April 2008 (UTC)
- You're responding to an old very-flawed article that got replaced, not to a talk comment or anything currently relevant. Dicklyon (talk) 14:55, 2 April 2008 (UTC)
a pixel is not a little square?
this is in the caption for a screen showing pixels as circles and other shapes.
Isn't it more appropriate to say "a pixel is not always a little square"? —The preceding unsigned comment was added by 144.136.5.191 (talk) 04:34, 20 December 2006 (UTC).
- Just because a pixel is sometimes rendered as a little square doesn't mean it ever is a little square. Dicklyon 06:37, 20 December 2006 (UTC)
- The definition of pixel rules out a pixel as any geometric shape, just as the smallest sample of a picture.LeinaD natipaC 18:34, 28 December 2006 (UTC)
- Indeed. A pixel can also be a rectangle (Television). Or a circle, for instance in a screen comprised of LED-panels; you know, you see those for instance at large events on Television such as award-parties. Or rather, in that case the pixel is a group of circles since one "pixel" (the smallest element in the display system that can change color) would be a group of 3 LED's: a blue, a green and a red one. It is true however, that in most display systems, pixels are arranged in rows and collumns (rather than in say a hexogonal beehive system or in circles, or totally random), which makes the pixels look like square from a distance. Or rectangle of course, if the distance between the rows doesn't equal the distance between the collumns. RagingR2 08:38, 11 April 2007 (UTC)
- Fuji made waves a while back when they made digital cameras with 'hexagonal' pixels.. Also, just recently NEC announced an LCD monitor that uses 'chevron' shaped pixels. 69.138.81.129 02:37, 16 June 2007 (UTC)
Where it mentions "Pixels on computer monitors are normally square", shouldn't it simply say that they are normally spaced the same horizontally as vertically? Even on an LCD, a pixel is three vertical rectangles side-by-side. —Preceding unsigned comment added by 66.90.244.113 (talk) 06:34, 23 July 2008 (UTC)
I think that saying that pixels on computer monitors are square is an over-generalization. Different graphics modes can have different aspect ratios. (Even on computers as old as the BBC B: mode 0 had a 2:1 1:2 aspect ratio IIRC, while mode 4 was 1:1, for instance... but since you didn't know what display you were going to output on, things could get complicated.) --Kim Bruning (talk) 22:17, 24 July 2008 (UTC) --late correction, mode 0 is ~1:2 To wit: 640x256 --Kim Bruning (talk) 21:26, 28 July 2008 (UTC)
- Hmm - I always read "Square" in the colloquial sense of the word, kinda like the usage of "square" in Madison Square Garden. Or, to add a little more context [3].
- That being said, I'm fine with it either way. IIRC, pixels on computer monitors are sposed to be 1.1 : 1 for normal resolutions - from a sampling perspective, 1:1 is ideal, but from a manufacturing and reliability perspective you want to go wider rather than taller to reduce costs. Good luck finding a cite for that tho :D
- 68.148.8.219 (talk) 21:11, 27 July 2008 (UTC)
- Actually, to try and retain some of the flavour and intent of the original, how do you feel about:
- "Pixels on computer monitors are (nearly) square, by contrast with..."
- 68.148.8.219 (talk) 21:16, 27 July 2008 (UTC)
Pixels on computer monitors are not square at all. They might be circular dots arranged in triangles (CRT), or groups of rectangles(LCD/TFT) (one such group may or may not be square)... or maybe some forms that happened since last time I looked (and on ink-jet printers they're groups of splotches of ink, thanks for asking :-P, other kinds of printers, and printing presses, and other devices that can render digital images have different representations. Devices such as plotters don't even typically use pixels at all). On the other hand, for ease of thinking about them, we often do think of pixels as idealized little squares, regardless of the medium we're going to render them to. This is to prevent us from going nuts, and for easy transfer between different media. Just don't be fooled into thinking those little squares actually exist anywhere in physical reality (unless you're making a tile mosaic using square tiles perhaps :-P) --Kim Bruning (talk) 21:21, 28 July 2008 (UTC) That and I really started to learn image editing on the Acorn Archimedes, which sported many 1:2 pixel formats... and thus had rectangular pixels.
Funnily: there's 356 google hits for "A pixel is not a little square." (Versus 54 for "A pixel is a little square". I'm not making this up. :-P --Kim Bruning (talk) 21:29, 28 July 2008 (UTC)
Oh, I'm wrong too (after reading some of those ghits). A Pixel is (or can be seen as) a point-sample. Duh. I am moron. --Kim Bruning (talk) 23:51, 28 July 2008 (UTC)
- hmm.. I still don't feel we've quite captured the spirit of the statement in question:
Pixels on computer monitors are normally rectangular, as are digital video formats with diverse aspect ratios, such as the anamorphic widescreen formats of the CCIR 601 digital video standard.
- So "square" and "rectangular" are being used colloquially here to mean "nearly 1 : 1 aspect ratio", by contrast to the digital video standards which are in some sense unfamiliar: 16:9 4:3 2.2:1
- When approaching these standards, there seems to be no reason for the strangeness, it's not until you uncover the history that it makes sense. The Acorn's 1 : 2 makes lots of sense, just double one of the axes, but how do you arrive at 2.2 : 1, or 2.3 : 1? (or 2.35 : 1 for that matter)
- Of course, all of this is confounded by the title of Alvy Ray Smith's original memo: "A Pixel Is Not A Little Square(x3)"
- TBH, I'm not sure what the right fix is...
- 68.148.8.219 (talk) 17:25, 4 August 2008 (UTC)
UXGA?
I'm having confusion regarding UXGA resolution. The article specifies it as 1600x1200 while my camera phone that is 2.0 Megapixel has the resolution 1632x1224. I did some searching around Google and found that companies advertise this resolution (1632x1224) ALSO as UXGA and not by another name.
1600x1200 = 1.92 Megapixel (Advertised as 1.9 MP or pseudo-2.0 MP)
1632x1244 = 1.997568 Megapixel (Advertised as [true] 2.0 MP)
So which one is UXGA? --ADTC 04:23, 8 April 2007 (UTC)
- UXGA is 1600x1200, anything that says differently is just using it as a buzzword. There is no formal **GA for 1632x1244 69.138.81.129 02:39, 16 June 2007 (UTC)
- Sounds good. What's your source? Dicklyon 02:52, 16 June 2007 (UTC)
Pixel geometry, and pixels not related to phosphors?
The caption to the article's third picture: "Phosphor dots in a color CRT display bear no relation to pixels or subpixels"
I am really wondering what's going on here. I don't see exactly what is meant here, and the article itself does not seem to make that point. Any clarifications to be made? --Edwin Herdman 13:06, 10 August 2007 (UTC) I think you did a very nice job in describing what a pixel is. Good Job
Q about a couple recent edits
Just wondering - not wanting to start an edit war or anything...
1/ "Removing unsupported item" (WUQSXGA) from "standard" display resolutions (could argue that MOST of the really-high, non-consumer sizes are hardly "standard" anyway). I didn't insert that list, but out of curiosity I did a quick google for the term as it seemed such a silly drawn-out one. I can give you two links right off that first page (of 10+ pages) that seem to use it as a standard term, and moreover, the ENTIRE list seems to have been copied from another page (credited, uncredited? I haven't gone thru the reference list to check), with WUQSXGA being original to it.
- http://www.woot.com/Forums/ViewPost.aspx?PageIndex=6&PostID=1666128
- http://en.wiktionary.org/wiki/WUQSXGA
(the third one i just checked, on yahoo answers, seems to be from the same source as the Woot one, so I haven't bothered including it)
I suppose it simply being on the internet isn't really a credible source, so do we have them for all the sizes up to the one immediately below it?
2/ Removal of the pixel size section as being "off topic". How can the typical size of a pixel on a normal display device be off topic, if a list of typical pixel resolutions is on-topic? The two are interrelated. You could say the resolutions are offtopic also, as they're not intrinsic to the definition of what a pixel is. Megapixel and Subpixel could also be split off into their own small articles.
I mean fine, go ahead, edit it down from the size it was at, I know I rattle on, I was getting the info down first and maybe chopping it back after I'd got it written so I didn't forget a pertinent point. The lists were a bit long, the sentences run on. But zapping the whole thing is a bit much when it's smaller form had been happily sitting there beforehand. Revert it instead if you really have to (and I'll simply do my original intent, before things on this Talk board sparked my interest, which was to correct the "typical pixel sizes" to more realistic ones - NO ONE makes a 15" 640x480 monitor, as far as I'm aware, and a 19" 1024x768 would be a rare sight indeed. IE, change the numbers at the ends of the lines)
PS, the stuff about Dot Pitch would be UTTERLY offtopic for the LCD page, though I guess LCD pixel size could (also) go there. It was included to show that measurements for different display technologies are discrete and not directly comparable.
(Actually, i'm not 100% if I got to the point of submitting that, given it was *still being written* when the section was zapped)
Thanks, "82.46.180.56" 82.46.180.56 (talk) 16:25, 2 April 2008 (UTC)
Similar concepts - surfel (?)
"Several other types of objects derived from the idea of the pixel, such as the voxel (volume element), texel (texture element) and surfel (surface element), have been created for other computer graphics and image processing uses."
Does 'Surfel' really belong in this list? My understanding is that a surfel is a (colored) point with a normal.
Contrast 'texel' - a pixel used as part of a texture, 'luxel' - a pixel representing a part of a lightmap, or 'voxel' - the 3d analogue of 2d pixels.
Sure, the naming of 'surfel' might have a similar motiviation, but I don't really see how it's a similar idea.
Thoughts? 68.149.174.115 (talk) 01:10, 15 June 2008 (UTC)
- If you have sources that tie them to "X element", then might as well mention them, with citation. Otherwise not. Dicklyon (talk) 02:51, 18 June 2008 (UTC)
- My Foley+VanDamme is in storage at the moment, but I'm pretty sure it mentions voxel and texel. Possibly luxel too. Will grab it soon.
- However the issue at hand is 'Surfel'. I don't believe it fits in this list. The naming is similar, but the idea is different:
- http://www.merl.com/projects/surfels <- (MERL was the group that came up with the word 'surfel')
- 68.149.174.115 (talk) 15:38, 18 June 2008 (UTC)
- So firstly, My ip address has changed *g* - so this is 68.149.174.115, but on a different DHCP lease.
- Second, added cite's for texel and voxel. Luxel isn't in my 1990 Foley+VanDam - go figure
- but most importantly, here's the abstract from the surfel paper:
Surface elements (surfels) are a powerful paradigm to efficiently render complex geometric objects at interactive frame rates. Un- like classical surface discretizations, i.e., triangles or quadrilateral meshes, surfels are point primitives without explicit connectivity. Surfel attributes comprise depth, texture color, normal, and oth- ers. As a pre-process, an octree-based surfel representation of a geometric object is computed. During sampling, surfel positions and normals are optionally perturbed, and different levels of texture colors are prefiltered and stored per surfel. During rendering, a hi- erarchical forward warping algorithm projects surfels to a z-buffer. A novel method called visibility splatting determines visible sur- fels and holes in the z-buffer. Visible surfels are shaded using tex- ture filtering, Phong illumination, and environment mapping using per-surfel normals. Several methods of image reconstruction, in- cluding supersampling, offer flexible speed-quality tradeoffs. Due to the simplicity of the operations, the surfel rendering pipeline is amenable for hardware implementation. Surfel objects offer com- plex shape, low rendering cost and high image quality, which makes them specifically suited for low-cost, real-time graphics, such as games
- I'm remain unconvinced the surfels are a similar concept to pixels. Similar etymology - sure. Concept - no.
- I think the right fix might be to change the section heading rather than the contents.
- Thoughts?
- 68.148.21.103 (talk) 14:59, 4 July 2008 (UTC)
Proposed New Section: Image Reduction (Downsampling)
(So the main article is getting pretty hairy in terms of reverts at the moment, so, I'm was thinking to try editing two new sections (downsampling and upsampling) here on the discussion page until we can get consensus, then migrate them across. Lets see how this goes!)
section head: Image Reduction (Downsampling)
Oftentimes, it is useful to take a large image and reduce it's size, perhaps for display purposes, to summarize an image, or simply to reduce the amount of image data required for storage or bandwidth considerations.
More generally, these type of operations can be seen as downsampling operations; taking an image with a large amount of information, and discarding or removing information which is no longer needed. Fourier analysis is a powerful technique for evaluating downsampling methods, a discrete Fourier transform converts both the original image and the downsampled image into frequency space, and hopefully the low frequencies remain unchanged, while the high frequency components have been removed.
An aggressive form of image reduction is thumbnailing. By presenting a user with a number of thumbnails of larger images, picking tasks can be significantly improved in terms of speed and accuracy. However, for automatic image summary and digital retrieval of images, methods based on the scale invariant feature transform provide better results.
A different type of downsampling occurs when the reducing the color space of an image. At the most extreme, the image is reduced to monochrome and halftoning is applied and often the spatial resolution is increased to compensate. For inkjet printing, most raster image processors use dithering patterns to strike a balance between preserving image detail and maintaining color reproduction.
Section Head: Upsampling
By contrast with downsampling, upsampling is the process of adding information to an existing image. It's a process that is closely linked with recovering information in an image that has previously been discarded, perhaps through previous image reduction, through JPEG compression, or through optical filters in an image capturing device.
In the absence of additional information about an image, a [[sinc filter] can be used to provide an "optimal reconstruction" of the missing high-frequency detail.
Paragraph: Forward error analysis, optimal reconstruction and the sinc filter
Paragraph: Artifacts, non-compact support, ringing, negative lobes
Paragraph: Windowing (bartlet, hanning etc)
Paragraph: Backward error analysis, likelihood function, finding the prior
Paragraph: PDE based methods
Paragraph: Pixel art scaling algorithms
(Please help by commenting / editing this section Constructively!) 68.149.174.115 (talk) 02:20, 18 June 2008 (UTC)
- There are various articles on image editing, image processing, etc., that would be much better places for such content. Dicklyon (talk) 02:50, 18 June 2008 (UTC)
- Is there any harm in having summaries of these techniques in the Pixel article? Specifically, the intent is to have a section "Downsampling pixels, from the POV of a pixel", whereas the image editing article seems more about editing an image from the POV of a user.
- As just one example, It seems an omission that (discrete) fourier analysis is not mentioned in the article at the moment.
- Thoughts?68.149.174.115 (talk) 15:12, 18 June 2008 (UTC)
Image scaling is an article specifically on this topic. I still don't think much needs to be said in the pixel article. Dicklyon (talk) 05:18, 7 August 2008 (UTC)
- Respectfully, I disagree. To re-iterate, I doesn't make sense for me for an article on pixels to omit mention of fourier transforms. The natural setting to introduce that concept is through image scaling.
- Is there some particular concept you feel doesn't warrant inclusion, or is it the shear volume of new material?
- 68.148.8.219 (talk) 17:24, 9 August 2008 (UTC)
- Well, I see it completely differently. I don't see why an article on pixels should get into Fourier transforms at all. It can have a brief mention of the frequency-domain view of sampling, resampling issues, etc., with links to relevant articles, but this is not a good place to try to explain all that stuff. Dicklyon (talk) 17:49, 9 August 2008 (UTC)
As for the upsampling, no, it's not about "adding information." Dicklyon (talk) 17:54, 9 August 2008 (UTC)
- Just found a cool link: http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-261.html (Haven't read thru it yet)
- 68.148.8.219 (talk) 04:18, 10 August 2008 (UTC)
- That looks like a good one, though a shorter "secondary" or "tertiary" source might be easier to work with. For example, sections in one or more of these books. Or this shorter paper by Dodgson. Dicklyon (talk) 05:11, 10 August 2008 (UTC)
4800 dpi printer
User: Dicklyon writes: "Without a secondary source, that product data is uninterpretable and unreliable."
Brother: http://review.zdnet.com/multifunction-devices/brother-mfc-685cw/4507-3181_16-32695816.html?tag=ut Max Printing Resolution up to 6000 x 1200 dpi (mono) / up to 6000 x 1200 dpi (color)
Canon: http://www.tomshardware.com/reviews/4800-dpi,545.html "when Canon says 4800 dpi, they don't mean actual resolution, but the number of "addressable" drops."
Epson: http://store.high-techoffice.com/hepade51inpr.html Prints at up to 5760 x 1440 optimized dpi
HP: http://www.shopbot.com.au/p-83624-2071526.html HP DeskJet D1460(CB632A) 4800 dpi, 12ppm(c) 16ppm(b), USB, XP/Vista Supported PRINTER
etc, etc, etc...
PPI: http://www.clarkvision.com/imagedetail/printer-ppi Tests of resolution charts show the HP printer just resolves 600 lines per inch (lpi), thus 600 ppi prints might show an advantage.
More PPI: http://www.luminous-landscape.com/reviews/printers/canon-ipf5000.shtml The image was a 169MB file at 600PPI, with 1200X2400 output resolution on 11X17" paper.
and finally, a (5760x)720 dpi printer for $100:
http://www.colamco.com/store/product/detail.aspx?product=577584&source=froogle Epson PictureMate Snap PM 240 - Printer - color - ink-jet - 4 in x 6 in - 5760 dpi x 720 dpi up
http://www.epson.com/cgi-bin/Store/consumer/consDetail.jsp?oid=63059184 Maximum Resolution (dots per inch) 5760 x 720 dpi This product is discontinued
... I could go on, but seriously, what's your agenda here?
WP:NOR 68.148.8.219 (talk) 17:29, 10 August 2008 (UTC)
- My agenda is to provide encyclopedic information. I think that to understand what these manufacturers mean in their marketing specs such as "addressable" and "optimized dpi", we need a reliable secondary source. It doesn't make sense to speak of 4800 dpi in the same sense that dpi was previously being used in the article, nor to claim a printer has 4800 dpi resolution when in one dimension its only 1200. Dicklyon (talk) 17:39, 10 August 2008 (UTC)
- Well, provide that information then.
- But to suggest that a high-quality inkjet printer in mid-2008 is only capable of 200 ppi is ludicrous and misleading:
http://www.usa.canon.com/consumer/controller?act=ModelInfoAct&fcategoryid=184&modelid=15596#ModelTechSpecsAct Print Resolution (Up to) Color: 9600 x 2400 dpi
- I've updated the example per the ClarkVision 2005 source. I didn't see any reason to take the example to 600 ppi, since 300 ppi is a more typical and credible example of a high-quality print. Nothing in the article suggests that this is the ultimate limitation of modern high-quality printers. Dicklyon (talk) 18:37, 10 August 2008 (UTC)
- Are you serious? A 3-year-old source?
- You made a mistake reverting. Admit it, apologize and move forward.
- If you want to try and be constructive (and encyclopedic), here's the passage that needs fixing:
- "...but have distinct meanings especially in the printer field, where dpi is a measure of the printer's resolution of dot printing (e.g. ink droplet density)."
- 68.148.8.219 (talk) 19:24, 10 August 2008 (UTC)
- You've lost me. Have I committed a grave injustice by referring to printers from 2005 as high quality, or what? You're probably right that the "dpi" thing is pretty flaky. I'll look for a source to improve it. Dicklyon (talk) 20:40, 10 August 2008 (UTC)
- No grave injustice, just a simple mistake: you reverted an accurate, good-faith edit.
- Well, here's your "implausible" printer:
- http://www.usa.canon.com/consumer/controller?act=ModelInfoAct&fcategoryid=184&modelid=15596#ModelTechSpecsAct
- Then you tried to cover your mistake with a printer which has since been discontinued (the HP 1220c), and attempting to use a definition of dpi which doesn't represent current industry practise:
- http://www.hp.com/hpinfo/newsroom/press/2002/020313a.html
- http://knoware.epson.com/Pages/EpAns.htm
- Canon, Epson, HP, and Brother all have inkjet printers for sale which are marketed as 4800 dpi or higher.
- Fix it please.
- 68.148.8.219 (talk) 02:07, 11 August 2008 (UTC)
- I don't doubt that your edit was in good faith; and whether it is "accurate" is not the issue. The issue is what's verifiable in reliable secondary sources. The manufacturers' marketing data spec don't qualify, in my opinion. That's why I selected the one source you cited above that was not by a manufacturer and didn't confuse dpi with resolution, and used it to support a reasonable example. Dicklyon (talk) 03:40, 11 August 2008 (UTC)
- I remain unconvinced. The paragraph in question discusses the use of the term dpi, in the printer field, of which Canon, Epson, HP and Brother are very much a part of, and have even published press releases and FAQs explaining exactly how they are using the term dpi. (see links above)
- In your opinion, why do you feel a 3-year-old secondary source is more reliable than multiple primary sources? (or am I misunderstanding your position? Do you feel that these printer manufacturers are not representative of the printer field?)
- 68.148.8.219 (talk) 01:13, 12 August 2008 (UTC)
- User:Dicklyon writes: "The issue is what's verifiable in reliable secondary sources."
- Furthermore, I disagree that this is the issue. I replaced an outdated unsourced statement with an up-to-date, unsourced statement. In the absence of citations, why should we not strive for accuracy?
- 03:15, 12 August 2008 (UTC)
- Fix it. Please. Or abandon your edit.
- 06:35, 14 August 2008 (UTC)
- Secondary sources are generally preferred to primary sources for interpretations. See WP:RS#Primary.2C_secondary.2C_and_tertiary_sources. And being 3 years old does not make the source any less appropriate here; high-quality inkjet printers have been around for quite a few years, and the main thing that has been advancing has been the specsmanship on dpi. Maybe we can find a source that talks about that... Dicklyon (talk) 15:58, 14 August 2008 (UTC)
- For the record, from WP:RS:
Primary sources — writings on or about a topic by key figures of the topic — may be allowable, but should be restricted to purely descriptive explanations of the subject or its core concepts. (emphasis mine)
- WRT a 3-year old source, inkjet printing is an active area of research. For example, this paper from 2003 which has immediate application to color inkjet printing if you can work out the masking issues. (pdf here: http://www.cs.unc.edu/~xffang )
- Or even more recently: http://appsrv.cse.cuhk.edu.hk/~ygqu/Halftone/index.htm
- To characterize increasing dpi as 'specsmanship' is to ignore the software advances that have been occuring over this timeframe.
- But fine. If this is where we have arrived at, then so be it. There are more important matters to attend to.
- 68.148.8.219 (talk) 01:14, 16 August 2008 (UTC)
- If you wanted to add sourced info, that could be useful; just mentioning manufacturers' specs when they're so inflated (and have been since at least 2002) is rather pointless. And it's all pretty much off-topic anyway, dpi not having much to do with the pixel concept. Dicklyon (talk) 02:54, 16 August 2008 (UTC)
This is an archive of past discussions about Pixel. Do not edit the contents of this page. If you wish to start a new discussion or revive an old one, please do so on the current talk page. |
Archive 1 |
Photosite
Not to get into the merits of Foveon but that article and several others use the term "photosite" which, far as I see, is nowhere defined in Wikipedia. Perhaps this Pixel article would be the best place to define it and explain its relation to the various meanings of "pixel". Jim.henderson (talk) 03:45, 16 June 2009 (UTC)
- You'd need a sourced definition to start with; it's probably just as ambiguous as "pixel" is. Dicklyon (talk) 04:11, 16 June 2009 (UTC)
- For example, if it were sourced, you could use the wiktionary definition, but it disagrees, I think, with some of the uses like in Foveon X3 sensor. Dicklyon (talk) 05:12, 16 June 2009 (UTC)
Abbreviation
The term "px" appears to be the abbreviation of the word "pixel." Can we confirm or debunk this?
- This section created by 63.226.104.225 and I'm just adding attribution. Looking at the user's talk page, it appears that this user has been a serial adder of unsigned comments and warned about vandalism before. DQweny (talk) 22:14, 18 October 2009 (UTC)
The following is not true, at least in case of CSS, which is linked as a reference. it can only be true for a 96dpi screen. The measurement in inches/mms changes as the screen dpi changes for a CSS unit of "px". "Pixels, abbreviated as "px", are also a unit of measurement commonly used in graphic and web design, equivalent to roughly 1⁄96 inch (0.26 mm). This measurement is used to make sure a given element will display as the same size no matter what screen resolution views it.[12]". The reference reads "The px unit is the magic unit of CSS. It is not related to the current font and usually not related to physical centimeters or inches either. The px unit is defined to be small but visible, and such that a horizontal 1px wide line can be displayed with sharp edges (no anti-aliasing). What is sharp, small and visible depends on the device and the way it is used: do you hold it close to your eyes, like a mobile phone, at arms length, like a computer monitor, or somewhere in between, like an e-book reader? The px is thus not defined as a constant length, but as something that depends on the type of device and its typical use."
Display Screen
I'm not sure how the meaning of "display" in LCD is but I thought it was the noun. Therefor LCD Screen would be wrong, wouldn't it? I'm not a native English speaker but where I come from people tend to say that even stranger, they say "LCD Display". I always thought "LCD" was enough. --80.109.201.185 (talk) 08:49, 27 October 2011 (UTC)
- LCD can sometimes be enough, but LCD display or LCD screen is not wrong, just more explicit. Dicklyon (talk) 14:58, 27 October 2011 (UTC)
The phrase "the smallest item of information in an image"
I have been checking copy-vio problems in the computer graphics article and happen to notice the phrase "the smallest item of information in an image" used there and here, apparently based on the source
- Rudolf F. Graf (1999). Modern Dictionary of Electronics. Oxford: Newnes. p. 569. ISBN 0-7506-43315.
Now I was wonder whether or not quotation marks have to be added? Eventually I think not, because this seems to be an exception in Wikipedia:Plagiarism, see here, which states:
- Here are some examples where attribution is generally not required:
- Use of common expressions and idioms, including those that are common in various sub-cultures such as academic ones. In order to qualify as a "common expression or idiom":
- the phrase must have been used without attribution at least 2 years ago by someone other than the originator and in a reliable source, in other words one that is likely to have watchful editors and lawyers.
- Use of common expressions and idioms, including those that are common in various sub-cultures such as academic ones. In order to qualify as a "common expression or idiom":
The particular phrase is used in at least two other books, see here
- Jill Marie Koelling (2004). Digital imaging: a practical approach. Rowman Altamira. p.1
- Joash Moo (2009). Art in life. Pearson Education South Asia. p.180
The first source expressed "A bit is the smallest piece of information in an image file", and the second source states: "Pixel : A picture element, which is the smallest piece of information in an image."
I am beginning to get second thoughts here. The second source could be based on Wikipedia, the first source is talking about "bits" and the original source Graf (1999) only mentioned the phrase "The smallest part of information in a binary notation system". I guess this leaves me with the question if Graf (1999) could be considered the source in the first place...!? -- Mdd (talk) 23:31, 18 November 2009 (UTC)
- Well, it's an interesting question. The second source you cite is a 2009 source, so you're probably right they got it from wikipedia. And the first is not about pixel per se. GBS will not show me the page with the pixel entry in Graf, so I can't check what he said. Decent definitions for pixel are notoriously difficult to find (at least, I hope I've made this problem notorious via my own paper and talk). Maybe we should look for a couple of alternative definitions to use instead. Dicklyon (talk) 23:41, 18 November 2009 (UTC)
- Thanks. I have the same GBS problem. I guess the easiest thing to do here is to find what Graf did say about pixels. I am not sure what paper you refer to. If they are indeed notoriously difficult to find, your last suggestion to search for some alternative one's might not be that easy? -- Mdd (talk) 23:52, 18 November 2009 (UTC)
- If you look at the history, e.g. this edit of mine, it appears that there's no reason to suspect that that phrase came from that source. I think you just moved it there, so you should probably move it back. The guy who cited Graf here said it was just for pixel = picture element. And then here an anon changed both the definition and what the source was attached to; I think it would be best take the lead back to something like what it said before this one. Dicklyon (talk) 23:54, 18 November 2009 (UTC)
- Ok, this is an interesting turn. I noticed you already made the changes... and removed the phrase. At the moment I think this is a good think to do: Since that phrase isn't based on Graf, my mistake, it could be possible that that phrase is a copy-vio from Koelling (2004). -- Mdd (talk) 00:15, 19 November 2009 (UTC)
- P.S. I also like this restored definition better "a pixel... is a single point in a raster image". Just plain and simple. -- Mdd (talk) 00:19, 19 November 2009 (UTC)
- I don't see how the phrase "the smallest piece of information in an image" for pixel could have been taken from "A bit is the smallest piece of information in an image file". Sometimes phrases just happen. "smallest piece of information" is in over 600 books. Dicklyon (talk) 00:28, 19 November 2009 (UTC)
- Mmm... The reason I started this talk item in the first place was, that the specific expression "the smallest piece of information in an image" seemed like a phrase that could be copyrighted. I read somewhere that an expression can start with just three words. But I don't know all ins and outs... one way or on other. I don't think I started this discussion for the wrong reason, and I appreciate your feed back and solution. I already implemented it in the computer graphics article as well. -- Mdd (talk) 00:44, 19 November 2009 (UTC)
- P.S. The phrase was added here without a source. Regarding the anon's other edits, see here this person does seem to be an expert in the field, and knows what he or she is talking about. -- Mdd (talk) 02:46, 19 November 2009 (UTC)
- Right, that's one of the diffs I linked. I don't see why you think he's an expert. Dicklyon (talk) 06:42, 19 November 2009 (UTC)
- Yes, you are right, sorry. The user did make some advanced additions to the article, and his last remark here. However I often have difficulties assissing situations like this. Do you think he is not? -- Mdd (talk) 12:13, 19 November 2009 (UTC)
- It's hard to guess. He seemed to be into the pixel article, and not much else, but not clear why. Dicklyon (talk) 00:40, 20 November 2009 (UTC)
- Hi! This is "Anon" from 2008, still posting anonymously to protect my employer, and still an expert in the field. Let me reassure you right now that the text I wrote earlier is in no way a copyright violation, it's simply a statement of fact using the language of signal processing: A pixel is indeed the smallest piece of information in an image.
- If I may be so bold as to contrast that with a misleading statement: "In digital imaging, a pixel, or pel, (picture element) is a *single point* in a raster image..." (emphasis mine)
- (Us in the industry would call that a single sample of a point-sampled image.)
- Mr Lyon, if you're still confused on the difference between a "sample" and a "point", please re-read the (somewhat quaint) first link listed: http://alvyray.com/Memos/CG/Microsoft/6_pixel.pdf
- Everybody, repeat it with me now, it feels good: "A pixel is *not* a little square." — Preceding unsigned comment added by 91.143.127.68 (talk) 00:39, 28 January 2012 (UTC)
- Anon, thanks for responding; just noticed. I'm in the industry, too; see my referenced publication [4]. It does go into the origins and widespread divergent meanings of pixel. And I'm pretty familiar with Alvy's paper, as it was I who linked it. I do realize that "sample" and "point" don't necessarily mean exactly the same thing; but changing point to sample probably also won't go far to making the article more correct or clear. Dicklyon (talk) 19:34, 5 February 2012 (UTC)
Contradictory - factor of three - are [RGB] one pixel or three pixels ?
Pixel is probably used in both senses, even throughout the article.
Cheap LCD photo frames tend to cheat on the specs We recommend a minimum resolution of 480 x 234 for 7" digital frames, and 800 x 600 for high resolution 10.4" digital frames That is really "480 x 78" or "160 x 234" not "480 x 234" - note that 800 isn't divisible by 3 ! So we have both meanings in one sentence! (Actually I'm having doubts about this - may have to check physically with some I own !)
Sigma claim other cameras inflate their pixel counts - I doubt it. That's really why I came here seeking clarification !
From the article: (I've used [x3] and [÷3] to show which definition is used ...)
- [X3] smallest, addressable element
- RG+B are individually addressed
- CRT pixels correspond to their timing mechanisms and sweep rates.
- I used to think the [RGB] phosphor dots were pixels, but they can be intersected by 2 raster lines
- The image to the right is confusing, despite the caption - can we get a photo showing raster lines within phosphor dots ?
- I have a 21" Hitachi with more pixels than dots, but would have to index-match the roughened anti-aliasing surface for photo-micrography. Anyone got a Trinitron and a photo-microscope ?
- In some contexts, the term pixel is used to refer to a single scalar element of a multi-component representation while in others the term may refer to the entire set of such component intensities for a spatial position.
- Yes! That sentence showed it is ambiguous...
- ... but people have stuck enough junk in brackets to hide the meaning ...
- In some contexts (such as descriptions of camera sensors), the term pixel is used to refer to a single scalar element of a multi-component representation (more precisely called a photosite in the camera sensor context, although the neologism sensel is sometimes used to describe the elements of a digital camera's sensor),[1] while in others the term may refer to the entire set of such component intensities for a spatial position. In color systems that use chroma subsampling, the multi-component concept of a pixel can become difficult to apply, since the intensity measures for the different color components correspond to different spatial areas in a such a representation.
- ... Clarify, please !
- A photograph of sub-pixel display elements
- [÷3] one pixel = 3 sub-pixels
- The number of pixels in an image is sometimes called the resolution
- [÷3] One wouldn't add red + green + blue resolutions, unless discussing information theory ?
- "640 by 480 display"
- [÷3] except cheap photo frames
- Subpixel rendering
- [÷3] one pixel = 3 sub-pixels
- Pixels on computer monitors are normally "square"
- [÷3] one pixel = 3 sub-pixels
- Each pixel is made up of triads
- [÷3] one pixel = 3 sub-pixels
- 2 bpp image can have 4 colors
- [X3] 4 levels each for R, G and B = 12 colours
- (Not to be confused with sRGBWeb_colors#HTML_color_names) !
- [÷3] one pixel = 3 sub-pixels
- I'm tempted to add "Sometimes known as 'Pixels' " !
- This section has been expanded until it loses all sense !
- It can be an ambiguous term
Who definitively, authoritatively owns the definition ?
- VESA defined SVGA etc, but charge for their published standards - anyone have a copy handy ?
There may be other industry bodies in different fields ?
I feel that at least the article in Wikipedia needs to be self-consistent - saying the global usage is ambiguous is not enough. Given the use of 'sub-pixel', and the absence of 'super-pixel', we should change the [x3] usages in the bulleted list above. That would be fewer changes, and consistent with HTML and Wiki-code.
Thoughts ?
---19S.137.93.171 (talk) 04:07, 8 May 2012 (UTC)
- 1 Pixel = 3 Pels ?
- 3 Pixels = 1 Pel ?
- 1 Pixel = 1 Pel !
- Shame - I had hoped that we could use one word for [RBG] and the other for [R], [B] or [G]
- Instead we use both words for both things !
- --195.137.93.171 (talk) 06:31, 25 May 2012 (UTC)
References
- ^ Michael Goesele (2004). New Acquisition Techniques for Real Objects and Light Sources in Computer Graphics. Books on Demand. ISBN 3833414898.
technical difference between software/hardware
is there one? is there a difference in nomenclature between software pixels & the pixels on screen? there should be... Lostubes (talk) 19:45, 5 March 2013 (UTC)
Another, related usage
Pixel can also refer to a hardware device that consists of an RGB LED, usually in conjunction with a small controller. These devices are often connected together in a string, similar to strings used as Christmas decorations. These pixel strings are often used to create electronic signage, as well as for holiday decorations.
First Sentence Confusion
The topic is pixel, and yet the first sentence starts making odd divisions in its useage by stating that it is used in digital devices (only?) and that "raster" differs in comparison to "display devices". It then speaks of smallest screen element, but then one finds that display devices includes tactile devices for the blind. Very confusing.
First, pixels may be used in analog displays, and second, raster is as opposed to vector. Is that not correct? Thanks. - KitchM (talk) 21:24, 7 September 2011 (UTC)
- I also had the feeling that pixels could also be used in the context of analog displays, but apparently the term emerged in use to refer to digital displays. I agree that the first sentence and first few paragraphs need to be clarified.
ozhu
量 (talk·contribs) 18:46, 17 July 2013 (UTC)
All points addressable
I'm trying to better integrate All Points Addressable into the encyclopedia. I don't think that should be a proper noun, all points addressable is what that should be titled, but since it's really never going to be more than a glossary term, it should probably be merged somewhere. Which gets me to the definition in the lead: : "a pixel is... the smallest addressable element in a display device". Shouldn't that say, "a pixel is... the smallest addressable element in an all points addressable display device"? Because certainly in text mode display devices such as the IBM Monochrome Display Adapter a character is the smallest addressable element, not a pixel. Maybe the definition of all points addressable can be moved to a new section of the pixel article, as all pixels addressable or simply pixel-addressable are equivalent terms. – Wbm1058 (talk) 02:29, 23 November 2013 (UTC)
Makyen's lead
I reverted again Makyen's change of the lead sentence to read:
- In digital imaging, a pixel (px), or picture element (pel), ...
The problem is that the cited sources do not support "px", and they support both pixel and pel as abbreviations of "picture element". If we're going to change it, we need to find what sources to use to support the new scheme, and be sure to at least write it consistently with those sources that we cite. In all my research on this topic (see my cited paper), I never encountered discussion of "px" that I can recall. Dicklyon (talk) 16:02, 2 January 2014 (UTC)
There's also the "Mpx" for megapixels. In book search, this seems to be only about 6% as common of Mp for megapixel; essentially an outlier, made up by authors who don't know better, and not really supported by anything authoritative. We should take it out to reduce the confusion. Dicklyon (talk) 16:06, 2 January 2014 (UTC)
- Thanks for starting the thread. You beat me to it by a sleep period 8-).
- I agree that I, also, have seen "p" used for abbreviating pixel. Sources, certainly for anything for which there is contention, are definitely needed. I also don't have a specific need for mentioning "px" in the lead. However, it is my natural inclination to put abbreviations at the first use of a term.
- The primary place that I have seen px used for pixel, in the last several years, has been in webpage development, including the Wikipedia software. The basis for this is the CSS specification. When searching for references, there were a plethora of additional third party sources which discussed this, including ones like Wikipedia:Markup#Images. Given the effectively ubiquitous use of "px" in the web design context, it is non-trivial to separate out sources which used "px" in other contexts (using web based sources for finding cites). W3C is also the only standards body, which I am currently thinking of, that has addressed the issue of an abbreviation of pixel. However, this may just be my more recent experience overshadowing memories from earlier years. If it is a book reference that you desire, I am sure that there are a large number of printed books which would provide such. Reference for W3C definition:
- <ref>{{cite web |url= http://www.w3.org/TR/CSS2/syndata.html#length-units |title=Syntax and basic data types |first= |last= |work=w3.org |year=2011 [last update] |quote=4.3.2 Lengths |accessdate=January 2, 2014}}</ref>
- There is a countering argument. The "px" abbreviation has been around through a sufficient development of technology such that it is becoming unclear if it is actually being used only for "pixel", as defined. In fact, the use of "px" as an abbreviation for "pixel", at least in this context, is sufficiently ingrained such that there is third party coverage (a blog, not appropriate for citing) attempting to explain where "px" is not actually intended to mean a device "pixel", but an abstraction due to pixels becoming too small to accommodate the intent behind the hundreds of millions of places "px" is used to mean pixel.
- In addition to the desire to add the abbreviation "px", I have an issue with how the first part of the lead is written. I did not re-write it, particularly after the first revert, because I felt that such rewrite would be considered to be more contentious. However, since we are discussing this, we should open up the issue of how that porton of the article is written. Honestly, I would want to spend some more time thinking about how I would consider it best stated. My initial issue is with the first sentence of (current article text):
- "In digital imaging, a pixel, or pel,[1] (picture element[2]) is a physical point in a raster image, or the smallest addressable element in an all points addressable display device; so it is the smallest controllable element of a picture represented on the screen. The address of a pixel corresponds to its physical coordinates. LCD pixels are manufactured in a two-dimensional grid, and are often represented using dots or squares, but CRT pixels correspond to their timing mechanisms and sweep rates."
- When first reading it, this sentence feels clunky. In addition, it does not mention pixel, the title of this article, as early as possible in the lead (recommended practice, MOS:BOLDTITLE). I would suggest something that begins something like:
- "A pixel (px),[3] or picture element (pel),[4][5] is a physical point in a raster image, or the smallest individually addressable element in an all points addressable display device. In digital imaging, it is the smallest, complete element of an image. The address of a pixel corresponds to its physical coordinates. LCD panels are manufactured with fixed pixels in a two-dimensional grid. CRT pixels correspond to the timing and activity of a beam of electrons striking phosphor on the glass. Pixels on print devices correspond to deposits of ink, or other material, on the print medium."
- Note: I removed "on a screen" because that excludes other output devices (e.g. printing). Added "complete" because there is an issue about sub-pixels. Other changes, really would like to put it aside and come back to it fresh. [Also note: initially I had intended to confine this to just the first sentence, but expanded it to the first paragraph.]
- I am not wedded to the above wording. I would usually want to write it down, leave and then come back to it later in order to look at it fresh. I do desire to see wording that is inclusive of other representations of a pixel than just specific to a screen. At a minimum, print devices should not be excluded and their mention needs to not exclude 3D printing. The rest of the first paragraph, as currently in the article, implies, by emphasis on screen types, that non-screen representations are excluded.
- As to Mp, or Mpx, p and px: Both MP and Mpx are mentioned in the text of the article. The problem with trying to easily find the relative popularity is that "p" is just too short for an accurate search; there are too many false positives. MP provides a bit better discrimination, and is a common abbreviation for megapixel. However, I would assert that the vast majority of those uses are where the context supports no other interpretation other than pixel. I would argue against the removal of any of them. Makyen (talk) 00:45, 3 January 2014 (UTC)
- If we're going to include px, we need something better than it being used as the code in computer languages like html/css and wiki markup. And as you note, the css px is not even about the same concept as pixel. Here are some useful searches for comparing Mp and Mpx: [5] and [6]. Try your own variants in books, scholar, web, or whatever. Looks like about 2% in books for Mpx. I don't see a major camera company using Mpx for megapixels; Sony and Canon use MP; Nikon and Sigma and Olympus appear to not abbreviate megapixel. Dicklyon (talk) 05:28, 3 January 2014 (UTC)
References
- ^ Foley, J. D.; Van Dam, A. (1982). Fundamentals of Interactive Computer Graphics. Reading, MA: Addison-Wesley. ISBN 0201144689.
- ^ Rudolf F. Graf (1999). Modern Dictionary of Electronics. Oxford: Newnes. p. 569. ISBN 0-7506-4331-5.
- ^ "Syntax and basic data types". w3.org. 2011 [last update]. Retrieved January 2, 2014.
4.3.2 Lengths
{{cite web}}
: Check date values in:|year=
(help)CS1 maint: year (link) - ^ Foley, J. D.; Van Dam, A. (1982). Fundamentals of Interactive Computer Graphics. Reading, MA: Addison-Wesley. ISBN 0201144689.
- ^ Rudolf F. Graf (1999). Modern Dictionary of Electronics. Oxford: Newnes. p. 569. ISBN 0-7506-4331-5.
kilopixel should be mentioned
The search "kilopixel" redirects to this article, but the term isn't found on the page. I can't figure out whether a kilopixel should mean 1000 or 1024. I think the former, but I don't know of a reference. Squish7 (talk) 02:49, 17 March 2015 (UTC)
- Do you have any examples of "kilopixel" actually being used in the real world? Because if not, and you can't find any reliable sources, then it's probably not notable enough for inclusion on Wikipedia. Indrek (talk) 08:53, 17 March 2015 (UTC)
- It is usual to mention one kilo is 1,000 and one mega is 1,000,000 for people without IT background, but the truth, one kilo is 1,024 and one mega is 1,024x1,024 (difficult to remember).Gsarwa (talk) 18:29, 4 April 2015 (UTC)
Photo Labs versus inkjet printer
I don't know it is useful and can be understood for/by the readers or not, but in fact inkjet printer has left behind a lot of Photo Labs, although nowadays there are some Photo Labs using also inkjet printer with more expensive price.
So, a camera with 24MP or 24,000,000 pixels (the precise pixels is more a bit than it) can produces in 8R paper size (8"x10") = a square root of (24,000,000/80) = a square root of 300,000 = 547dpi, theoritically. But due to paper photo labs commonly only produce maximum 300dpi, so the result will always 300dpi or lower, while even the modest A4 1440x1440 pixels (1440dpi) inkjet printer can produces more image resolution than paper photo labs, with note excellent inkjet photo paper and excellent inkjet photo dye/ink are expensive.Gsarwa (talk) 18:52, 4 April 2015 (UTC)
- I see a few issues with that paragraph.
- First, is it notable? Wikipedia is not an indiscriminate collection of information. For something to be included in an article, it needs to have some encylopaedic value, and to improve the article in some way.
- Second, is it sourced? Wikipedia does not accept original research, any information must be attributable to reliable sources. Specifically, you'd need sources that back up the claims you're making about photo labs and inkjet printers.
- Finally, that text seems to be only tangentially related to pixels, and (assuming the above two criteria are met) would be better suited for inclusion in another article like Inkjet printing, Digital printing or Printer (computing). Indrek (talk) 19:17, 4 April 2015 (UTC)
- I agree. It seems to be saying that print resolution is determined by pixels per inch and/or dots per inch; there are pretty loose relationships. In my experience, a good 300 pixel per inch photo printer beats a high-dpi inkjet, but I'm willing to concede that it could just as well go the other way. We'd need sources to clarify what the comparison is, who judged it, and such. Dicklyon (talk) 05:12, 5 April 2015 (UTC)
2.0 Megapixel Image Necessary?
Do you really think we need this image?
In my opinion, it does not add anything to the article, and I think it actually detracts from the aesthetics of the article. Tell me what you think. I'll delete it in a week if nobody objects. Henrib736 (talk) 03:25, 6 April 2014 (UTC)
- No objections here, though if possible, maybe it could be replaced with a higher-quality image showing the same thing (megapixel markings on a digital camera). Indrek (talk) 10:21, 6 April 2014 (UTC)
- Nowadays cameras usually use at least 16MP, if there are better image with bigger resolution, I think we should replace the current image.Gsarwa (talk) 18:16, 4 April 2015 (UTC)
- In my understanding, the point the image is making is that the megapixel war at one point was so intense that the spec was marked in large recessed letters on the hardware, to two significant figures. Samsara 06:46, 5 April 2015 (UTC)
Maximum info possible to contain in a pixel
Quickly reading the article it seems that a pixel is what I have always thought, roughly put: the smallest piece of information in a picture, most commonly rendered as a square but which can also be interpreted so as to blur its edges and overlap it with its neighbouring pixels, as the diagram http://en.wikipedia.org/wiki/File:ReconstructionsFromPixels.png seems to show. Now, while I have always laughed at the photo-enhancing programs that are the staple of the CSI etc series (e.g the barely visible and miniscule reflection in the sunglasses of somebody in a photo, being enhanced to show in high resolution the face of someone standing behind the camera) due to their ubiquitousness I am now beginning to doubt myself. Surely there can be no more information in a photograph (for instace) than is contained at the level of its pixels. Photo-enhancing is presumably simply the blurring/softening referred to, but can someone confirm how much information can be contained in one pixel? An episode of the sublimely absurd Numbers last night had a pixel containing half a dozen names. Secondly I came across a web-design tutorial http://www.drdobbs.com/the-single-pixel-gif/184411862 regarding single pixel gifs that can be stretched to any size. Is this simply a mix-up in terminologies or can a pixel span many pixels?!? It's not possible from the article to determine the answers to these quite basic questions. LookingGlass (talk) 14:22, 4 April 2013 (UTC)
- Yes, the CSI stuff is nonsense. The single-pixel GIF is just a transparent rectangle that you can stretch to cover any number of screen pixels. There's no information in it. Dicklyon (talk) 06:55, 5 April 2013 (UTC)
Thanks. Sometimes the sheer volume of BS makes me doubt my sanity! LookingGlass (talk) 19:07, 5 April 2013 (UTC)
- A pixel is a sample, and as such, in a bayesian sense, constrains a prior. If you know that an image is of a person, or a number plate, or a computer screen displaying ASCII characters, then yes, you can reconstruct priors that have more detail than is present in the sample. Ifucnrdthssntc,UknwwhtImtkgabt. This is still true, even if the only prior you know is that the image is a photograph of the real world. Point being the "CSI Enhance" isn't quite as ridiculous as was one assumed. (Anon from 2008) — Preceding unsigned comment added by 122.61.46.240 (talk) 12:24, 12 September 2019 (UTC)
"1.3 megapixel" listed at Redirects for discussion
A discussion is taking place to address the redirect 1.3 megapixel. The discussion will occur at Wikipedia:Redirects for discussion/Log/2020 May 16#1.3 megapixel until a consensus is reached, and readers of this page are welcome to contribute to the discussion. TheAwesomeHwyh 00:09, 16 May 2020 (UTC)
Inventor of pixel
The page for Russell Kirsch credits him as the "inventor of the pixel," yet he does not appear in this article, and the term is credited here to others, so either this page is incomplete or the other page is wrongly attributing the invention to him. — Preceding unsigned comment added by 71.198.178.65 (talk) 00:31, 14 August 2020 (UTC)