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This page should probably be consolidated with the codec page
The information in the image captions is confusing and seems to conflict with itself.
If it is 108.5 KB when uncompressed, then how can the original, lossless image be 60.1 KB?
So... is this compressed to 84% or 16% of the original file size? Is 9.37 KB the loss of information or the compressed file size?
I have doubts about the accuracy of these numbers because, to me, the examples of low and medium compression don't seem to differ from the original image at all. I am also concerned that "low" compression is said to reduce the file size from 60.1 KB (or is it 108.5 KB?) to a mere 9.37 KB without any apparent loss. To me, a loss of 84% of data is not low and should create visible degradation. -- Humanist Geek ( talk) 01:15, 16 May 2010 (UTC)
It's obvious to the naked eye that the low compression and medium compression photos are swapped. Unfortunately, it's that way in the originals, not just in this article. You can confirm that by the file size too. The medium compression file size is bigger than the low compression file size. It should be smaller. With such a goofy mistake, I wouldn't trust the other numbers either. -- 98.151.165.109 ( talk) 21:53, 23 October 2012 (UTC)
I think the examples used in this article should be larger (or at least have links to larger versions) so people can easily examine the images and note the differences between the examples.-- Humanist Geek ( talk) 01:15, 16 May 2010 (UTC)
This is the proper forum to discuss the image in question, rather than trying to squeeze the comments in the history. I chose the Lena image because it is the standard image to use when you talk about any type of image processing. As far as I can determine, the image is still under Playboy copyright, but it is practically in the public domain (perhaps it already is?) because of its proliferation. This is the image that should be used. - grubber 17:48, 2005 July 22 (UTC)
What do you think? -- Shlomital 11:31, 14 October 2005 (UTC)
It doesn't actually say anywhere that the above "lossy" images aren't PNGs like the "original." I was mislead for a second, and someone who's just learning this kind of stuff will walk away thinking PNGs are lossy. Ninetigerr ( talk) 05:29, 9 September 2008 (UTC)ninetigerr
I've managed to find a TIFF version of the Lena image, on one of the sites linked to from the Wikipedia article Lenna. Upon inspection, the image contains noise resultant of scanning, but no artifacts of lossy compression.
My prievous image (of the dog) is the best I could offer as a replacement free of licensing problems (my copyright, released under the GFDL); I don't see how I can put an image comparable to Lena in its suitability for the demonstration of lossy compression, as I can't see myself taking some person's picture and putting it on Wikipedia. I hope the choices so far give you enough room to make a decision. -- Shlomital 15:18, 14 October 2005 (UTC)
For the images in the article, the compression isn't linear is it? Isn't it rounded so that at a certain point there is not much of a difference even if it is compressed more? And that in the beginning, compression saves more than is taken. 70.111.218.254 20:21, 5 November 2006 (UTC)
This page really needs a mention of transcoding and a link, but I don't have the time nor knowledge to really do it justice. disastrophe 03:54, 6 November 2007 (UTC)
you cannot compress lost information. —Preceding unsigned comment added by 88.218.156.7 ( talk) 05:41, 27 October 2009 (UTC)
I've always hated the term "lossy compression" but for some reason it stuck. Throwing information away to get a smaller file size is not the same as compressing it. The algorithms involved may be just as intensive but the overall result is not the same, so the term is a misnomer. If I were to take a foam ball in hand and squeaze it to make it smaller that would be true compression. Release the hand and the ball returns to its ORIGINAL size. If I carve the ball down all I have is a smaller ball. Each ending result has its own advantages but loss of any kind should not be associated with compression. — Preceding unsigned comment added by Drake5150 ( talk • contribs) 22:39, 13 November 2011 (UTC)
Nil Einne ( talk) 16:00, 13 December 2022 (UTC)When put under compression (or any other type of stress), every material will suffer some deformation, even if imperceptible, that causes the average relative positions of its atoms and molecules to change. The deformation may be permanent, or may be reversed when the compression forces disappear. In the latter case, the deformation gives rise to reaction forces that oppose the compression forces, and may eventually balance them.
I appreciate the inclusion of transform coding and understand the relevance of perceptual data vs actual data. That being said, ANY data that is discarded is ONLY a reduction in file size. I'm not knocking the result...but can we change the name to something else ? — Preceding unsigned comment added by Drake5150 ( talk • contribs) 23:22, 13 November 2011 (UTC)
Something looks wrong about the dog images. The Low compression picture is blurrier than the Medium compression image. For instance, on the left of the image, the background green has blurry brown spots in the "low" setting but clear brown spots in the original and the medium. Also on the left of the picture, the grey tufts on the dogs ear are clear strands in the original and medium image, but just a blur on the low compression image. It looks like the medium and low have been mixed up. — Preceding unsigned comment added by 202.89.177.154 ( talk) 14:52, 1 August 2012 (UTC)
Can we remove the Amiga HAM (Hold and Modify) reference? HAM is not a compression format lossy or otherwise: it's a screen display mode aimed at overcoming early Amiga computer hardware limitations in showing more than 32 (or 256) colours simultaneously. HAM pictures were IFF-ILBM, which used lossless runlength encoding.
Converting a truecolour picture to HAM did indeed lose information, but technically so does converting it to less colours or less size. I wouldn't call this lossy compression, because it isn't compression. Opinions?
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This page should probably be consolidated with the codec page
The information in the image captions is confusing and seems to conflict with itself.
If it is 108.5 KB when uncompressed, then how can the original, lossless image be 60.1 KB?
So... is this compressed to 84% or 16% of the original file size? Is 9.37 KB the loss of information or the compressed file size?
I have doubts about the accuracy of these numbers because, to me, the examples of low and medium compression don't seem to differ from the original image at all. I am also concerned that "low" compression is said to reduce the file size from 60.1 KB (or is it 108.5 KB?) to a mere 9.37 KB without any apparent loss. To me, a loss of 84% of data is not low and should create visible degradation. -- Humanist Geek ( talk) 01:15, 16 May 2010 (UTC)
It's obvious to the naked eye that the low compression and medium compression photos are swapped. Unfortunately, it's that way in the originals, not just in this article. You can confirm that by the file size too. The medium compression file size is bigger than the low compression file size. It should be smaller. With such a goofy mistake, I wouldn't trust the other numbers either. -- 98.151.165.109 ( talk) 21:53, 23 October 2012 (UTC)
I think the examples used in this article should be larger (or at least have links to larger versions) so people can easily examine the images and note the differences between the examples.-- Humanist Geek ( talk) 01:15, 16 May 2010 (UTC)
This is the proper forum to discuss the image in question, rather than trying to squeeze the comments in the history. I chose the Lena image because it is the standard image to use when you talk about any type of image processing. As far as I can determine, the image is still under Playboy copyright, but it is practically in the public domain (perhaps it already is?) because of its proliferation. This is the image that should be used. - grubber 17:48, 2005 July 22 (UTC)
What do you think? -- Shlomital 11:31, 14 October 2005 (UTC)
It doesn't actually say anywhere that the above "lossy" images aren't PNGs like the "original." I was mislead for a second, and someone who's just learning this kind of stuff will walk away thinking PNGs are lossy. Ninetigerr ( talk) 05:29, 9 September 2008 (UTC)ninetigerr
I've managed to find a TIFF version of the Lena image, on one of the sites linked to from the Wikipedia article Lenna. Upon inspection, the image contains noise resultant of scanning, but no artifacts of lossy compression.
My prievous image (of the dog) is the best I could offer as a replacement free of licensing problems (my copyright, released under the GFDL); I don't see how I can put an image comparable to Lena in its suitability for the demonstration of lossy compression, as I can't see myself taking some person's picture and putting it on Wikipedia. I hope the choices so far give you enough room to make a decision. -- Shlomital 15:18, 14 October 2005 (UTC)
For the images in the article, the compression isn't linear is it? Isn't it rounded so that at a certain point there is not much of a difference even if it is compressed more? And that in the beginning, compression saves more than is taken. 70.111.218.254 20:21, 5 November 2006 (UTC)
This page really needs a mention of transcoding and a link, but I don't have the time nor knowledge to really do it justice. disastrophe 03:54, 6 November 2007 (UTC)
you cannot compress lost information. —Preceding unsigned comment added by 88.218.156.7 ( talk) 05:41, 27 October 2009 (UTC)
I've always hated the term "lossy compression" but for some reason it stuck. Throwing information away to get a smaller file size is not the same as compressing it. The algorithms involved may be just as intensive but the overall result is not the same, so the term is a misnomer. If I were to take a foam ball in hand and squeaze it to make it smaller that would be true compression. Release the hand and the ball returns to its ORIGINAL size. If I carve the ball down all I have is a smaller ball. Each ending result has its own advantages but loss of any kind should not be associated with compression. — Preceding unsigned comment added by Drake5150 ( talk • contribs) 22:39, 13 November 2011 (UTC)
Nil Einne ( talk) 16:00, 13 December 2022 (UTC)When put under compression (or any other type of stress), every material will suffer some deformation, even if imperceptible, that causes the average relative positions of its atoms and molecules to change. The deformation may be permanent, or may be reversed when the compression forces disappear. In the latter case, the deformation gives rise to reaction forces that oppose the compression forces, and may eventually balance them.
I appreciate the inclusion of transform coding and understand the relevance of perceptual data vs actual data. That being said, ANY data that is discarded is ONLY a reduction in file size. I'm not knocking the result...but can we change the name to something else ? — Preceding unsigned comment added by Drake5150 ( talk • contribs) 23:22, 13 November 2011 (UTC)
Something looks wrong about the dog images. The Low compression picture is blurrier than the Medium compression image. For instance, on the left of the image, the background green has blurry brown spots in the "low" setting but clear brown spots in the original and the medium. Also on the left of the picture, the grey tufts on the dogs ear are clear strands in the original and medium image, but just a blur on the low compression image. It looks like the medium and low have been mixed up. — Preceding unsigned comment added by 202.89.177.154 ( talk) 14:52, 1 August 2012 (UTC)
Can we remove the Amiga HAM (Hold and Modify) reference? HAM is not a compression format lossy or otherwise: it's a screen display mode aimed at overcoming early Amiga computer hardware limitations in showing more than 32 (or 256) colours simultaneously. HAM pictures were IFF-ILBM, which used lossless runlength encoding.
Converting a truecolour picture to HAM did indeed lose information, but technically so does converting it to less colours or less size. I wouldn't call this lossy compression, because it isn't compression. Opinions?
Hello fellow Wikipedians,
I have just modified one external link on Lossy compression. Please take a moment to review my edit. If you have any questions, or need the bot to ignore the links, or the page altogether, please visit this simple FaQ for additional information. I made the following changes:
When you have finished reviewing my changes, you may follow the instructions on the template below to fix any issues with the URLs.
This message was posted before February 2018.
After February 2018, "External links modified" talk page sections are no longer generated or monitored by InternetArchiveBot. No special action is required regarding these talk page notices, other than
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(last update: 18 January 2022).
Cheers.— InternetArchiveBot ( Report bug) 13:45, 6 January 2018 (UTC)