possible bug histogram of JP2

[fmw42]

Testing for an issue reported at viewtopic.php?f=27&t=32596

I get a different looking histogram when saving the red channel of a tif to JP2 than I do with PNG. I have tested with IM 7.0.6.10 and IM 6.9.9.10

input tiff:
http://www.fmwconcepts.com/misc_tests/h ... g/luna.tif

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magick luna.tif -channel r -separate -quality 0 luna_r.jp2

http://www.fmwconcepts.com/misc_tests/h ... luna_r.jp2

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magick luna_r.jp2 histogram:luna_r_hist.gif

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magick luna.tif -channel r -separate luna_r.png

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magick luna_r.png histogram:luna_r_png_hist.gif

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magick compare -metric rmse luna_r.jp2 luna_r.png null:

114.797 (0.0017517)

So there is a slight difference is the two images. Would this slight difference cause the spikes in the jp2 histogram that is seen above?

[magick]

Thanks for the problem report. We can reproduce it and will have a patch to fix it in GIT master branch @ https://github.com/ImageMagick/ImageMagick later today. The patch will be available in the beta releases of ImageMagick @ https://www.imagemagick.org/download/beta/ by sometime tomorrow.

[dlemstra]

This commit fixed it: https://github.com/ImageMagick/ImageMag ... 446a59b6e0