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How does this MozJPEG 2.0 encoding compare to JPEGMini? I've been using JPEGMini for all client projects, it results in optimized JPEGs that work on all platfor

How does this MozJPEG 2.0 encoding compare to JPEGMini? I've been using JPEGMini for all client projects, it results in optimized JPEGs that work on all platforms with minute differences, rarely visible to the naked eye, only when I subtract pre/post in Photoshop. Very rarely does it save less than 5% and for larger images (saved with PhotoShop, save for web) often 15-30% or even more. Is the test set of images available?

muizelaar 12y ago
jpegmini works by compressing an image as much as possible while keeping the distortion calculated by there particular metric below a threshold. To compare against mozjpeg you'd need to compress a bunch of images with JPEGMini and then compress those images with mozjpeg so that they were the same size. You could then compare the quality of the resulting images. The test set of images is here: https://github.com/bdaehlie/web_image_formats/tree/master/images https://github.com/bdaehlie/web_image_formats/tree/master/im... If you're interested, https://github.com/dwbuiten/smallfry https://github.com/dwbuiten/smallfry is program similar to JPEGMini that uses mozjpeg as its backend.
- ZeroGravitas 12y ago
  How much extra saving does JPEGMini or smallfry offer over a sanely but conservatively encoded JPEG?
mzs 12y ago
http://people.mozilla.org/~josh/lossy_compressed_image_study_july_2014/#image_sets http://people.mozilla.org/~josh/lossy_compressed_image_study... mozjpeg does Trellis quantization, there is no detailed explanation about jpegmini, a guess is it optimizes the DCT similarly to how it is described in this paper: http://vision.arc.nasa.gov/publications/sid93/sid93.pdf http://vision.arc.nasa.gov/publications/sid93/sid93.pdf
- muizelaar 12y ago
  There are some papers by the JPEGMini people that give a pretty good hint as to how it works: http://spie.org/Publications/Proceedings/Paper/10.1117/12.872231 http://spie.org/Publications/Proceedings/Paper/10.1117/12.87... http://spie.org/Publications/Proceedings/Paper/10.1117/12.872230 http://spie.org/Publications/Proceedings/Paper/10.1117/12.87...
ajslater 12y ago
jpegrescan AFAIK is the gold standard today. https://github.com/kud/jpegrescan https://github.com/kud/jpegrescan

muizelaar 12y ago

jpegmini works by compressing an image as much as possible while keeping the distortion calculated by there particular metric below a threshold. To compare against mozjpeg you'd need to compress a bunch of images with JPEGMini and then compress those images with mozjpeg so that they were the same size. You could then compare the quality of the resulting images. The test set of images is here: https://github.com/bdaehlie/web_image_formats/tree/master/images https://github.com/bdaehlie/web_image_formats/tree/master/im... If you're interested, https://github.com/dwbuiten/smallfry https://github.com/dwbuiten/smallfry is program similar to JPEGMini that uses mozjpeg as its backend.

ZeroGravitas 12y ago
How much extra saving does JPEGMini or smallfry offer over a sanely but conservatively encoded JPEG?

mzs 12y ago

http://people.mozilla.org/~josh/lossy_compressed_image_study_july_2014/#image_sets http://people.mozilla.org/~josh/lossy_compressed_image_study... mozjpeg does Trellis quantization, there is no detailed explanation about jpegmini, a guess is it optimizes the DCT similarly to how it is described in this paper: http://vision.arc.nasa.gov/publications/sid93/sid93.pdf http://vision.arc.nasa.gov/publications/sid93/sid93.pdf

muizelaar 12y ago
There are some papers by the JPEGMini people that give a pretty good hint as to how it works: http://spie.org/Publications/Proceedings/Paper/10.1117/12.872231 http://spie.org/Publications/Proceedings/Paper/10.1117/12.87... http://spie.org/Publications/Proceedings/Paper/10.1117/12.872230 http://spie.org/Publications/Proceedings/Paper/10.1117/12.87...

ajslater 12y ago

jpegrescan AFAIK is the gold standard today. https://github.com/kud/jpegrescan https://github.com/kud/jpegrescan