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Is JPEG-LS subject to patents in any developed country that require payment by implementors? -- Damian Yerrick ( ☎) 14:07, 16 July 2006 (UTC)
since this covers all 3 lossless JPEG formats shouldn't it be titled appropriately, i propose "lossless variants of JPEG" Plugwash 17:08, 31 July 2006 (UTC)
JPEG-LS does not get higher compression ratios than JPEG2000 with any of the public domain software. For a test, I compared JPEG2000 (Meesoft Image Analyzer) to JPEG-LS (University of British Columbia's implementation) on Kodak test images. ( http://r0k.us/graphics/kodak/) JPEG2000 got more than a 2:1 compression ratio on all of them, and they correctly decompress losslessly. JPEG-LS did much worse; some of them were larger than the original PNG files.
If JPEG-LS is able to get higher compression ratios than lossless JPEG2000, why does every JPEG-LS implementation I try do a little better than PNG, but much WORSE than lossless JPEG2000? Korejwa 19:38, 15 August 2006 (UTC)
In summary, though, I don't know what accounts for the difference. Hopefully you can hazard a guess. Calbaer 21:20, 15 August 2006 (UTC)
In my experience, JPEG-LS is better than JPEG 2000 lossless mode for grayscale images, but it isn’t the case for color images. JPEG-LS usually compress color components independently, while JPEG 2000 can employ reversible color transform (RCT) to remove inter-color correlations. JPEG-LS part 2 specifies a new color transform technique but it has not been popular. 124.87.182.116 19:33, 10 August 2007 (UTC)
BTW: jpeg lossless mode (not jpeg LS) seems to often compress worse than png. For fotos the compression rate is similar to png, often a little above 50%), but for line-drawings, it falls much behind (probably because it needs to store at least one bit per pixel and color). -- 77.3.85.66 ( talk) 17:21, 26 January 2016 (UTC)
The JPEG lossless compression article doesn't contain anything interesting, there was a "Merge" proposal, but its discussion page was deleted. Shouldn't it be simply redirected to the Lossless JPEG page? cojoco ( talk) 00:25, 11 December 2008 (UTC)
I agree. Having many pages talking about essentially the same thing is really confusing to someone unfamiliar with the subject. 202.21.130.193 ( talk) 21:04, 15 January 2009 (UTC)
This article is listed in Category:Lossy_compression_algorithms, which I find quite paradoxal given its title, but I am not sure I should just remove it. Ffx ( talk) 13:44, 22 January 2009 (UTC)
I think a section to this effect would be in order. Does anybody here have the expertise to write it? -- Smjg ( talk) 19:39, 5 July 2009 (UTC)
I cannot find anything about this in the DCT article. Maybe we should name the real problems: Reduced color resolution and quantization. It would, for example, be possible to use the lossy jpeg, and use an entropy coder to save the residual errors. Speed/compression may not be that good. -- Arnero ( talk) 15:51, 8 May 2010 (UTC)
More on "the Inverse DCT is not rigorously defined" The inverse DCT in JPEG standard is rigorously defined. The problem is in a concrete DCT implementation. Indeed, DCT is specified with functions 'cos' which produces irrational (even transcedental) outputs. Therefore any finite-precision implementation is actually an approximation of the DCT. This causes a mismatch between between original and reconstructed sources even if quantization scaler is 1. —Preceding unsigned comment added by 199.203.96.62 ( talk) 12:53, 31 October 2010 (UTC)
-- RokerHRO ( talk) 12:05, 13 April 2011 (UTC)
The article says about LL mode of standard JPEG:
This mode is quite popular in the medical imaging field, and defined as an option in DNG standard, but otherwise it is not very widely used because of complexity of doing arithmetics on 10, 12 or 14bpp values on typical embedded 32bit processor and a little resulting gain in space.
But this LL-mode of standard JPEG is used by cameras (Canon CR2, Adobe DNG,...) to encode RAW image data. Probably because these arithmetics are the easiest way on embedded hardware.
-- 77.8.118.19 ( talk) 03:55, 19 January 2016 (UTC)
What does the "LS" in JPEG-LS stand for? I would think "lossless" would be JPEG-LL. Other readers might also like to know... — Preceding unsigned comment added by 118.0.51.1 ( talk) 12:48, 29 November 2017 (UTC) "Low-complexity Standard"?
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With regard to this statement: "This mode is quite popular in the medical imaging field, and defined as an option in DNG standard, but otherwise it is not very widely used because of complexity of doing arithmetics on 10, 12 or 14bpp values on typical embedded 32-bit processor and a little resulting gain in space." Actually, the lack of support is primarily because the compression in lossless mode is comparable to other lossless JPEG modes which have already been widely studied; further, the compression gains of near-lossless mode are explicitly prohibited by the FDA -- irreversible compression is not permitted. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3259360/
Lossless JPEG (1993) is supported for read and write in Jasc Paint Shop Pro version 9. The compression is poor.
There is a JPEG-LS plugin for Adobe Photoshop provided by Hewlett-Packard (on the Wayback Machine). It supports color channel decorrelation, which improves the compression ratio greatly compared to IrfanView, and is comparable to XL at effort 3. All applications with an LS plugin still support these files.
-- J7n ( talk) 21:02, 15 May 2024 (UTC)
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Is JPEG-LS subject to patents in any developed country that require payment by implementors? -- Damian Yerrick ( ☎) 14:07, 16 July 2006 (UTC)
since this covers all 3 lossless JPEG formats shouldn't it be titled appropriately, i propose "lossless variants of JPEG" Plugwash 17:08, 31 July 2006 (UTC)
JPEG-LS does not get higher compression ratios than JPEG2000 with any of the public domain software. For a test, I compared JPEG2000 (Meesoft Image Analyzer) to JPEG-LS (University of British Columbia's implementation) on Kodak test images. ( http://r0k.us/graphics/kodak/) JPEG2000 got more than a 2:1 compression ratio on all of them, and they correctly decompress losslessly. JPEG-LS did much worse; some of them were larger than the original PNG files.
If JPEG-LS is able to get higher compression ratios than lossless JPEG2000, why does every JPEG-LS implementation I try do a little better than PNG, but much WORSE than lossless JPEG2000? Korejwa 19:38, 15 August 2006 (UTC)
In summary, though, I don't know what accounts for the difference. Hopefully you can hazard a guess. Calbaer 21:20, 15 August 2006 (UTC)
In my experience, JPEG-LS is better than JPEG 2000 lossless mode for grayscale images, but it isn’t the case for color images. JPEG-LS usually compress color components independently, while JPEG 2000 can employ reversible color transform (RCT) to remove inter-color correlations. JPEG-LS part 2 specifies a new color transform technique but it has not been popular. 124.87.182.116 19:33, 10 August 2007 (UTC)
BTW: jpeg lossless mode (not jpeg LS) seems to often compress worse than png. For fotos the compression rate is similar to png, often a little above 50%), but for line-drawings, it falls much behind (probably because it needs to store at least one bit per pixel and color). -- 77.3.85.66 ( talk) 17:21, 26 January 2016 (UTC)
The JPEG lossless compression article doesn't contain anything interesting, there was a "Merge" proposal, but its discussion page was deleted. Shouldn't it be simply redirected to the Lossless JPEG page? cojoco ( talk) 00:25, 11 December 2008 (UTC)
I agree. Having many pages talking about essentially the same thing is really confusing to someone unfamiliar with the subject. 202.21.130.193 ( talk) 21:04, 15 January 2009 (UTC)
This article is listed in Category:Lossy_compression_algorithms, which I find quite paradoxal given its title, but I am not sure I should just remove it. Ffx ( talk) 13:44, 22 January 2009 (UTC)
I think a section to this effect would be in order. Does anybody here have the expertise to write it? -- Smjg ( talk) 19:39, 5 July 2009 (UTC)
I cannot find anything about this in the DCT article. Maybe we should name the real problems: Reduced color resolution and quantization. It would, for example, be possible to use the lossy jpeg, and use an entropy coder to save the residual errors. Speed/compression may not be that good. -- Arnero ( talk) 15:51, 8 May 2010 (UTC)
More on "the Inverse DCT is not rigorously defined" The inverse DCT in JPEG standard is rigorously defined. The problem is in a concrete DCT implementation. Indeed, DCT is specified with functions 'cos' which produces irrational (even transcedental) outputs. Therefore any finite-precision implementation is actually an approximation of the DCT. This causes a mismatch between between original and reconstructed sources even if quantization scaler is 1. —Preceding unsigned comment added by 199.203.96.62 ( talk) 12:53, 31 October 2010 (UTC)
-- RokerHRO ( talk) 12:05, 13 April 2011 (UTC)
The article says about LL mode of standard JPEG:
This mode is quite popular in the medical imaging field, and defined as an option in DNG standard, but otherwise it is not very widely used because of complexity of doing arithmetics on 10, 12 or 14bpp values on typical embedded 32bit processor and a little resulting gain in space.
But this LL-mode of standard JPEG is used by cameras (Canon CR2, Adobe DNG,...) to encode RAW image data. Probably because these arithmetics are the easiest way on embedded hardware.
-- 77.8.118.19 ( talk) 03:55, 19 January 2016 (UTC)
What does the "LS" in JPEG-LS stand for? I would think "lossless" would be JPEG-LL. Other readers might also like to know... — Preceding unsigned comment added by 118.0.51.1 ( talk) 12:48, 29 November 2017 (UTC) "Low-complexity Standard"?
Hello fellow Wikipedians,
I have just modified 4 external links on Lossless JPEG. 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
regular verification using the archive tool instructions below. Editors
have permission to delete these "External links modified" talk page sections if they want to de-clutter talk pages, but see the
RfC before doing mass systematic removals. This message is updated dynamically through the template {{
source check}}
(last update: 5 June 2024).
Cheers.— InternetArchiveBot ( Report bug) 13:45, 6 January 2018 (UTC)
With regard to this statement: "This mode is quite popular in the medical imaging field, and defined as an option in DNG standard, but otherwise it is not very widely used because of complexity of doing arithmetics on 10, 12 or 14bpp values on typical embedded 32-bit processor and a little resulting gain in space." Actually, the lack of support is primarily because the compression in lossless mode is comparable to other lossless JPEG modes which have already been widely studied; further, the compression gains of near-lossless mode are explicitly prohibited by the FDA -- irreversible compression is not permitted. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3259360/
Lossless JPEG (1993) is supported for read and write in Jasc Paint Shop Pro version 9. The compression is poor.
There is a JPEG-LS plugin for Adobe Photoshop provided by Hewlett-Packard (on the Wayback Machine). It supports color channel decorrelation, which improves the compression ratio greatly compared to IrfanView, and is comparable to XL at effort 3. All applications with an LS plugin still support these files.
-- J7n ( talk) 21:02, 15 May 2024 (UTC)