Wikipedia:Reference desk/Archives/Computing/2022 February 11

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February 11

Why do websites host images in png formats mostly?

I believe jpg/jpeg image is lossless image compression than png, then why do websites host images in png formats mostly? Rizosome (talk) 06:55, 11 February 2022 (UTC)

Read Portable Network Graphics. --←Baseball Bugs ^{What's up, Doc?} carrots→ 07:42, 11 February 2022 (UTC)

It is the other way around. JPEG uses lossy compression, while PNG supports lossless compression if full colours (like 24-bit RGB) are used. For photographic images, JPEG is generally preferred. For text images or schematic diagrams with solid colours and crisp edges, PNG tends to give better results.  --Lambiam 11:25, 11 February 2022 (UTC)

I got the answer from this line: PNG supports lossless compression if full colours (like 24-bit RGB) are used. Rizosome (talk) 04:48, 14 February 2022 (UTC)

@Rizosome: A strong reason to use PNG (as on Wikipedia) is that PNG supports 8-bit (256 levels of) transparency whereas JPEG supports none (GIF supports 1-bit or 2 levels), allowing images to be overlaid on a background, such as markers on a map. cmɢʟee⎆τaʟκ 11:52, 18 February 2022 (UTC)

How do I copy software that appears to be an ad?

Actually, I have a different question. Although copy and paste is not working so I can't ask what programming language I am seeing, I am also wondering why I would see the software that is supposed to produce the ad, rather than the ad itself.

But I would like to be able to copy so I can ask someone what programming lanugage I am seeing.— Vchimpanzee • talk • contributions • 23:49, 11 February 2022 (UTC)

Can you not take a screenshot? Or, failing that, a photo? Matt Deres (talk) 02:50, 12 February 2022 (UTC)

Can you download the page and open it in an editor? I tend to use wget(1) or curl(1) under Linux, I'd hope Windows has something similar if that's your preference. Martin of Sheffield (talk) 09:53, 12 February 2022 (UTC)

I guess a screenshot would be an option, but then what would I do with it?— Vchimpanzee • talk • contributions • 17:09, 12 February 2022 (UTC)

You can use an online OCR service to convert the image to text and post the text here.  --Lambiam 23:29, 12 February 2022 (UTC)

Nothing happened today but I'll take a screenshot next time. As I recall, I save it to Paint.— Vchimpanzee • talk • contributions • 20:06, 12 February 2022 (UTC)