Wikipedia:Reference desk/Archives/Computing/2021 January 1

= January 1 =

Image Pixels in TIFF to JPEG conversion?
If I make sure to preserve the maximum quality of digital images every single time when I convert them from TIFF format to JPEG format, I should not expect to encounter any change in the amount of pixels or the dimension of those images, correct? For example, if I convert this this image to jpeg, the dimension of the new image would still be 4,016 × 2,953 pixels, correct? StellarHalo (talk) 07:03, 1 January 2021 (UTC)
 * Image dimensions are usually not changed during conversions into another format. Ruslik_ Zero 12:13, 1 January 2021 (UTC)
 * Right. The quality in conversion to JPG is not about the number of pixels but about how accurately the original colors of pixels can be reproduced from the compressed jpg file. "maximum quality", "100%" or whatever your image software calls it, may still not be able to reproduce the exact colors. If there is an option called "lossless" then it should work. Roughly speaking, JPEG uses that pixels in the same area often have nearly the same color in a photo, and the human eye doesn't notice small changes. It often works poorly for drawings where clear lines may become blurry. The P in JPG is for Photographic. PrimeHunter (talk) 12:45, 1 January 2021 (UTC)
 * Note that modern TIFF is more of a container than a simple file format. It it possible to store one or more JPEGs inside a TIFF, and a well designed program should be able to extract these without recompression. That said, as per our article or [//graphicdesign.stackexchange.com/questions/91366/clipping-path-in-tiff-how-to-make-use-of-it], TIFF can also store a vector path and other things so there's no guarantee of no loss even if the TIFF does have JPEG inside it. Nil Einne (talk) 15:07, 1 January 2021 (UTC)

Why is the address so long?
I was looking for a photo that appeared on a newspaper web site and found the option to search for it on Google. Ordinarily I would right-click and "copy image address" but the image is part of a video. I can't post the "address" here because it would take up most of the page. Where would be a good place to put it so you can see how long it is and maybe see enough information to figure out why it so long?— Vchimpanzee  •  talk  •  contributions  •  23:55, 1 January 2021 (UTC)
 * A URL can be very long. Anything under 2,000 characters is normal. There is no hidden meaning behind URL length. It as long as it needs to be. 97.82.165.112 (talk) 01:49, 2 January 2021 (UTC)


 * I often see links posted that contain a lot of unnecessary detail, such as a search string that led to the page, or some info about the referring site, or even what browser was used. Sometimes I try snipping each of the fields (strings bounded by ?...&...&...) to see which of them make a difference in the resulting page. —Tamfang (talk) 03:06, 2 January 2021 (UTC)
 * pastebin.com or https://gist.github.com/discover are good places for cut-and-paste snippets. Elizium23 (talk) 11:45, 2 January 2021 (UTC)
 * Just tell us the Google search and which result you picked. That may also tell us more than the address itself. If you are looking for a shorter address then say that. A long "address" starting with  can contain an image and not just link to it. MediaWiki doesn't allow it in links so I cannot post a clickable example but you can copy-paste this to the address bar for a small example:
 * data:image/gif;base64,R0lGODlhEAAQAMQAAORHHOVSKudfOulrSOp3WOyDZu6QdvCchPGolfO0o/XBs/fNwfjZ0frl3/zy7////wAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAACH5BAkAABAALAAAAAAQABAAAAVVICSOZGlCQAosJ6mu7fiyZeKqNKToQGDsM8hBADgUXoGAiqhSvp5QAnQKGIgUhwFUYLCVDFCrKUE1lBavAViFIDlTImbKC5Gm2hB0SlBCBMQiB0UjIQA7
 * PrimeHunter (talk) 12:10, 2 January 2021 (UTC)
 * I can't repeat the Google search at this time but by trying I ended up with a shorter URL and a better version of the photo. I was sort of hoping, though, that someone could explain the very long "address".— Vchimpanzee  •  talk  •  contributions  •  16:39, 2 January 2021 (UTC)
 * It is not a real address, but a use of the data URI scheme. The string contains a base64 encoding of the pixels of the image; in this case 16×16 = 256 pixels. --Lambiam 12:26, 6 January 2021 (UTC)
 * Okay, thanks. I couldn't reproduce the search, but my attempt gave me a better version of the photo.— Vchimpanzee  •  talk  •  contributions  •  16:37, 6 January 2021 (UTC)