This patent can be defeated.
Please see my comments:
http://www.geocities.com/mpegminus/IPR/RLD/index.h tml
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This patent US 4698672 (and similar Philips US4901075 patent) are the two most infamous ones known within MPEG. Claim 6 of the former reads onto JPEG and MPEG. It concerns the simple "2-D" run-length entropy symbol coding trick, where the most probable combination of run-of-zeros and coefficient levels are combined into a single token. It provides some small boost to coding efficiency. This patent can be circumnativated by, for example, resorting back to 1D run-length coding (separate tokens for zero-run and non-zero level), or more advanced techniques like CAVLC recently developed in H.26L (known by a silly number of other names such as, but not limited to: AVC, MPEG-4 Part 10, H.264, VCEG, and JVT !!).
Much like sequental block to progressive transmission scan transcoders that repack an existing JPEG image today, a lossless transcoder could easily convert JPEG files to a number of non-infringing formats, albeit not decodable by older JPEG decoders. You do not have to alter the numerical outcome of the picture.
However, thanks to the stupid and relentless behaviour of the claimants, prior art has been found recently that will invalidate both and will probably be made public within a year.
The Wen-Chen patent has been agressively asserted by CLI (now Forgent) for nearly a year already. Several Asian companies have already settled. The Vogel patent (Philips) US 4901075 covers essentially the same concept.
The truth shall lower your royalties!
MPEG-
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A list of prior art is given in the history paper linked at this website:
http://www.geocities.com/mpegminus/
In any event, JPEG could be tweaked to circumvent this infamous patent by losslessly transcoding the 2D-run-length symbols to something else.
In fact, every JPEG picture in the world could be filtered without altering a single pixel, and would completely avoid this patent.
This patent can be defeated. Please see my comments: http://www.geocities.com/mpegminus/IPR/RLD/index.h tml
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This patent US 4698672 (and similar Philips US4901075 patent) are the two most infamous ones known within MPEG. Claim 6 of the former reads onto JPEG and MPEG. It concerns the simple "2-D" run-length entropy symbol coding trick, where the most probable combination of run-of-zeros and coefficient levels are combined into a single token. It provides some small boost to coding efficiency. This patent can be circumnativated by, for example, resorting back to 1D run-length coding (separate tokens for zero-run and non-zero level), or more advanced techniques like CAVLC recently developed in H.26L (known by a silly number of other names such as, but not limited to: AVC, MPEG-4 Part 10, H.264, VCEG, and JVT !!).
Much like sequental block to progressive transmission scan transcoders that repack an existing JPEG image today, a lossless transcoder could easily convert JPEG files to a number of non-infringing formats, albeit not decodable by older JPEG decoders. You do not have to alter the numerical outcome of the picture.
However, thanks to the stupid and relentless behaviour of the claimants, prior art has been found recently that will invalidate both and will probably be made public within a year.
The Wen-Chen patent has been agressively asserted by CLI (now Forgent) for nearly a year already. Several Asian companies have already settled. The Vogel patent (Philips) US 4901075 covers essentially the same concept.
The truth shall lower your royalties!
MPEG-