Talk:JPEG

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Former good article nominee JPEG was a good articles nominee, but did not meet the good article criteria at the time. There are suggestions below for improving the article. Once these issues have been addressed, the article can be renominated. Editors may also seek a reassessment of the decision if they believe there was a mistake.
October 28, 2007 Good article nominee Not listed
WikiProject Computing / Software (Rated B-class, High-importance)
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It's probably not DCT, it's flood fill ![edit]

You make a balanced flood fill over the source image that aborts when the average of all covered pixels differs with the current pixel by more than a tolerance limit. The covered area is then filled with the average value of all of it's pixels. When you compress the result with RLE or ZIP, you'll see that a lot of redundancy can be won without completely ruining the image. When the resulting image doesn't look that good or photorealistic, you can still interpolate the areas with sinus or cosinus formed shades and it will get a bit better.

IE info in lead outdated, or ambiguous?[edit]

In the lead: "The MIME media type for JPEG is image/jpeg, except in older Internet Explorer versions". This is ambiguous. In the source I find: "In Microsoft Internet Explorer 4.0 and later, MIME type determination occurs in URL monikers through the FindMimeFromData method." so it could mean "in all current Internet Explorer browser down to 4.0".

Maybe I'm not reading this right, does the "expect" apply to IE4 up to some IE that is still old? Then maybe drop this from the lead as too much trivia? If this does not apply to Microsoft Edge (does it?) then at least this will get dated at some point.. comp.arch (talk) 16:36, 12 December 2015 (UTC)

According to this may have changed as of "ie 9 image/jpeg image/bmp image/gif image/png"[1]
"But some applications (most notably MS Internet Explores but also Yahoo! mail) send jpeg files as image/pjpeg
I thought I knew that pjpeg stood for 'progressive' jpeg. It turns out that progressive/standard encoding has nothing to do with it. MS Internet explorer send out all jpeg files as pjpeg regardless of the contents of the file.
The same goes for citrix: all jpeg files send from a citrix client are reported as the image/x-citrix-pjpeg MIME type."[2]
See also: http://stackoverflow.com/questions/115705/why-does-ie7-specify-a-mime-type-of-image-pjpeg-rather-than-just-image-jpeg comp.arch (talk) 17:30, 12 December 2015 (UTC)

Lossless editing[edit]

@Waerloeg: your qualifier isn't limited to rotations, or is it? On commons I sometimes state "lossless crop with XnView" assuming that it's understood to be not really lossless for width x height != m*8 x n*8. –Be..anyone 💩 17:03, 22 April 2016 (UTC)