possible bug combining non-RGB colorspace channels

[fmw42]

IM 6.7.8.7 Q16

The following round trip from RGB to HSL/HSB and back to RGB is failing for IM 6.7.8.7, but works for IM 6.7.6.10 and IM 6.7.4.10

I tried both wasy (with and without making the input image linear color or leaving it non-linear color. The result of both is a grayscale image and not the original color image. The miff image layers look fine. So I believe it is with the recombination, perhaps the -compose R/B/B.


Input:



Processing with IM 6.7.8.7


convert monet3.jpg -colorspace HSL -separate 1tmp.miff
convert 1tmp.miff[0] -colorspace HSL \
1tmp.miff[0] -compose CopyRed -composite \
1tmp.miff[1] -compose CopyGreen -composite \
1tmp.miff[2] -compose CopyBlue -composite \
-colorspace sRGB monet3_HSL_rt.jpg



convert monet3.jpg -set colorspace RGB -colorspace HSL -separate 2tmp.miff
convert 2tmp.miff[0] -colorspace HSL \
2tmp.miff[0] -compose CopyRed -composite \
2tmp.miff[1] -compose CopyGreen -composite \
2tmp.miff[2] -compose CopyBlue -composite \
-colorspace RGB monet3_HSL_rt2.jpg


Is this a bug, or am I misunderstanding something here. It does work fine for IM before 6.7.7.8

[fmw42]

Further information. This does not fail in IM 6.7.8.6 or in IM 6.7.8.7 with HDRI. It only fails in 6.7.8.7 non-hdri

[magick]

We can reproduce the problem you reported and have a patch in ImageMagick 6.7.8-8 Beta by sometime tomorrow. Thanks.

[fmw42]

We can reproduce the problem you reported and have a patch in ImageMagick 6.7.8-8 Beta by sometime tomorrow. Thanks.

This appears to be fixed in the latest 6.7.8-8 beta, today.