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The technology is very different. Both translate the image into a representation where it's easier to remove "unimportant" data. JPEG is based on discrete cosin
by ahartmetz 5y ago
The technology is very different. Both translate the image into a representation where it's easier to remove "unimportant" data. JPEG is based on discrete cosine transform (DCT), JPEG2000 on wavelet transform.
Visually, where JPEG produces ringing artifacts, JPEG2000 produces blurriness. JPEG artifacts look "sparkly" and are often a reasonable replacement for the original texture, JPEG2000 artifacts look offensively dull (my opinion). I think, in theoretical speak, it's called "JPEG better preserves high frequency energy". You should be able to find side by side comparisons using your favorite image search engine.
- ahartmetz 5y agoI've found a nice example. Compare the lawn, the part above the arc (especially on the right) and the uppermost window on the two 0.17 MB images. There are parts that look like the JPEG2000 encoder inserted big blotches where details should be. JPEG2000 seems to be better at large, gentle gradients and strong discontinuities between solid colored regions. https://www.imagepdf.com/images/jpeg2000.jpg https://www.imagepdf.com/images/jpeg2000.jpg