Wikipedia:Reference desk/Archives/Computing/2013 July 25

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July 25

Why does my cell phone screen have inverted colors....

...but only when viewed from the right side, not straight on, or from the left, top, or bottom ? (Samsung S425G.) StuRat (talk) 05:11, 25 July 2013 (UTC)

I was going to say that is "characteristic of LCD displays" but from only the right side seems odd. (and I am assuming that its LCD (Liquid-crystal display) not OLED (organic light-emitting diode) or some other technology?) And a little OR, my computer LCD monitor 'inverts' from the top but not from either side. --220 of ^Borg 05:27, 25 July 2013 (UTC)

It's regular LCD as far as I know. Sounds like my screen is mounted 90° relative to yours, but the question remains as to why LCD screens behave that way, and in particular why from only one direction. StuRat (talk) 06:43, 25 July 2013 (UTC)

Well there are several varieties of LCD, some of which difference is aimed at improving 'viewing angle'. Twisted nematic is apparently the cheapest and most common, In-Plane Switching LCD is better as far as view angle. Interestingly I lifted my monitor so I could look from beneath and lo-and-behold, NO inversion! If anything the contrast gets better and colours darker. (it's a ChiMei CMV 938D, I can't find out exact type of display it is.) So it is not just your LCD displaying this directional character.

I wonder if the 'normal' viewing angle for phone displays is offset to allow for the fact that some of the time the phone will be near your ear or in one hand and not directly in front of you like a PC monitor or TV would often be. (Apparently this is possible, I'm trying to find the source again.) This ZDNet page may be of interest, "How LCD makers lie to you about viewing angles" It seems to show the one direction inversion you are asking about on a Twisted Nematic display.
* I've had a good Google around and while there are a lot of how-LCD-works explanations, this effect is not addressed --220 of ^Borg 09:25, 25 July 2013 (UTC)

Strange; mine inverts if you look down from the top. If you look from either side, the screen gets a rose-coloured tint. If you look from the bottom, it gets a blue-coloured tint... --Yellow1996 (talk) 16:35, 26 July 2013 (UTC)

Each pixel on an LCD display is made up of at least 3 (R, G, B) subpixels, masked by an LCD shutter. The subpixels and the LCD shutters are on two slightly different planes. When viewed from an off-angle, the shutters end up blocking out the wrong subpixels (or part of the right one and part of a wrong one), leading to color distortion effects. The reason behind StuRat's asymmetrical distortion will depend on the exact geometry of the display elements. 209.131.76.183 (talk) 17:05, 26 July 2013 (UTC)

Interesting. Why can't they just turn the subpixels on and off directly, rather than leaving them on and using a mask ? That would both fix the viewing angle problem and increase display time on a single charge, right ? StuRat (talk) 01:18, 27 July 2013 (UTC)

That is essentially how an OLED display works. gnfnrf (talk) 12:04, 29 July 2013 (UTC)

Copying text from FlashPaper

Hi... the museum I work for just received a donation of plaques describing the Sikh contribution to the World Wars. They just published an article about the contribution, and I was hoping to machine translate it for our Facebook audience.

Thing is, the paper is in FlashPaper, which doesn't let you copy with Ctrl+C or right click, etc.

I have Adobe Acrobat Pro installed on this machine at work, at when I print the newspaper as a PDF through Pro, it turns it into an image. Microsoft Office Document Imaging won't OCR in Punjabi, we only have EN/FR/ES installed. Any ideas of how this might work? All I need to do is copy the text out, I've got translating it covered. Thanks! -- Zanimum (talk) 12:35, 25 July 2013 (UTC)

Oh, here's the document I'm trying to copy from (page 3). -- Zanimum (talk) 12:36, 25 July 2013 (UTC)

Different tech issue: I switched out of Chrome, over to IE, and I can copy, but I end up getting this, no matter where I paste:

  ª´±Ò ´ÓÙ§ 
 ³Ó¹´¾º® 
 ¾®ÇÒ°¬² ¼§ ·­¬× 
 ¸º´ ·ª©½ ¾¨§ 
 °×´ ¿º®¬ ¹Ç´®× 
 ø¿¶º·»¾Ù®÷ 
 ´»× ·­©ÕÚ ª´±Ò

-- Zanimum (talk) 12:46, 25 July 2013 (UTC)

I was going to suggest printing it to a pdf then using acrobat reader's text selection tool. However, the text all came out as pictures. Looks like you might have to get some Punjabi OCR software or do it the hard way and get a (human) translator working on it.

The whole idea behind Flash Paper seems to be to restrict copying and printing. Could you find the originator of the paper? Astronaut (talk) 16:06, 25 July 2013 (UTC)

The page won't load for me so I can't try anything - but I agree with Astronaut. You'll probably have to do it the hard way (manual translation, doing up a whole new document) unless you can contact the original author of the paper. FlashPaper seems to be meant for copy-protection; the random characters you are getting when you copy the text is the result of the security precautions. --Yellow1996 (talk) 16:09, 25 July 2013 (UTC)

If you have a device that can scan to PDF, try printing out the document, then scanning it back in, then running Acrobat's OCR on the scan. -- 140.202.10.134 (talk) 18:03, 25 July 2013 (UTC)

PC LOAD LETTER

The problem of printers insisting on Letter sized paper is a major headache for almost anyone with anything to do with computers in Europe (where the standard is A4). From that article: For comparison, the letter paper size commonly used in North America (8.5 in × 11 in (216 mm × 279 mm)) is approximately 6 mm (0.24 in) wider and 18 mm (0.71 in) shorter than A4. I've never seen an office that had both sizes in stock, and apart from some US Embassies perhaps, none of the printers sold in the entire continent of Europe has ever been used to print on Letter sized paper. I've never seen something that suddenly didn't fit because it was printed on A4. I've never even seen someone having benefit from the fact that the actual letters where printed on envelopes so the printer really helped out. I've been on the phone with clients and family quite a lot to explain how to get out of this mess, due to my profession that must have been at least 200 hours of totally wasted time. I cannot think of anything in the IT business that is this stupid. A printer sold with "won't whine about paper sizes" is actually worth a lot extra in terms of TCO. Maybe I should have asked at the humanities desk, but what in the world were and still are printer manufacturers thinking when they came up with this "feature"? Clippy was a mistake, FTP still is bad, and I can't find the option to scan in Word anymore without asking Google, but the horror that mere printing brings us each and every day is really uncomparable. (The fact that Windows fakes a heart attack when it encounters a Canon 2001-23-15A instead of the Canon 2001-23-15F it expected, with no option to tell it to just try needs perhaps another rant, but that really is peanuts compared to customers calling with "it flashes and says load letter, and turning it off and on didn't help") Joepnl (talk) 22:49, 25 July 2013 (UTC)

They were thinking about selling their printers in the US, of course. (Your question is very difficult to understand, by the way. Simpler prose would help.) Looie496 (talk) 22:59, 25 July 2013 (UTC)

English is not my first language, sorry. It's still strange that printer manufacturers make printers for the US and sell those in Europe. They can think of the difference in voltage for example. Joepnl (talk) 23:07, 25 July 2013 (UTC)

What should a printer do if the job's page size doesn't match the loaded paper size? Options are:

1. scale the job - but then the printout doesn't match preprinted stock (letterhead, forms), address blocks don't match window envelops, graphics and logos aren't in proportion (and boy do you get an angry phonecall from the guy in Corporate Communications whose job it is to preserve brand integrity).
2. crop the job - smaller onto larger produces margins wider than they appear in Word; larger onto smaller produces narrower ones, or stuff off the page altogether. And again things don't match preprinted stock.
3. scale a bit, crop a bit - the problems of the above two, but to a lesser degree
4. PC LOAD LETTER, which has all the problems you describe

There isn't a perfect solution. 1,2, and 3 weren't possible on an old dot-matrix printer, because the printer was too dumb to do scaling and cropping - but a PostScript printer can. Most people don't care (that much) about the problems of 1,2, and 3, but if they do, they'll blame the printer for being defective. If the printer complains, it's the user's fault - so #4 is the politic solution for the printer manufacturer. They'd say (perhaps with reason) that the OS' print system should fix this - after all, it knows the paper size of the document and these days usually knows the paper size in the printer (because the printer's wire protocol allows it to find that out). By that logic, when you try to print letter on legal etc. the print dialog should pop up and say "that doesn't fit, how do you want me to handle it (1,2,3,4)?". In practice most domestic printers are junk (£30 for a 5ppm colour all-in-one scan/fax/printer - of course it'll be junk), and office printers are expensive and terrible. Incidentally, if I understand how CUPS pre-rasterisation filters are supposed to work, it should be possible to write one(s) that notice the job doesn't match the paper and mutate the job by 1,2, or 3. -- Finlay McWalterჷTalk 23:32, 25 July 2013 (UTC)

Interestingly, from Letter (paper size):

"Unlike the A4 (210 × 297 mm) international standard (ISO) paper sizes which are used in most countries in the world today, the origin of the dimensions of letter size paper are lost in tradition. The American Forest and Paper Association argues that the dimension originates from the days of manual paper making, and that the 11-inch length of the page is about a quarter of "the average maximum stretch of an experienced vatman's arms". However, this does not explain the width or aspect ratio." --Yellow1996 (talk) 00:51, 26 July 2013 (UTC)

This is not a printer problem. The paper size is specified in the print job and the printer is not in the business of second guessing what you (via your computer) told it to do. The problem is that the computer is misconfigured, and you should be able to fix it in the printer properties somewhere, or by complaining to whoever should've done that. I have to say that I've printed a lot of letter-size documents in the UK and A4-size documents in the US (mostly academic papers in PDF or PS format) and I can't remember ever having had this problem. The printer driver always knew what kind of paper was in the printer and the PDF viewer fit the actual page size to the dimensions of the paper. -- BenRG (talk) 07:33, 26 July 2013 (UTC)