magick -gamma -1,-1,0 does not produce all-yellow image

[pgajdos]

magick ../test.png  -gamma -1,-1,0  -alpha off  yellow_gamma.png

taken from https://usage.imagemagick.org/canvas/ does not produce all-yellow image, but rather all-white one.

Or

magick ../test.png -channel red -gamma -1 -channel green -gamma -1 -channel blue -gamma 0 -alpha off yellow_gamma.png

produces

Similar to ImageMagick/ImageMagick#1151.

Tested with 7.1.1-43.

[pgajdos]

magick convert ../test.png -channel red -gamma -1 -channel green -gamma -1 -channel blue -gamma 0 -alpha off yellow_gamma.png

(the longer version + magick convert instead of magick) produces expected result, i. e. all-yellow image.

[urban-warrior]

Thank you for reporting the issue. We have successfully reproduced it and are actively working on a patch to resolve it. You can expect this patch to be merged into the main GIT branch, later today. As part of our commitment to quality, this fix will also be included in the upcoming beta releases of ImageMagick by tomorrow. Your patience and feedback are greatly appreciated.

[pgajdos]

Thank you a lot, much appreciated!

Just one nitpick, according:

https://www.imagemagick.org/discourse-server/viewtopic.php?p=147784&sid=49f72e9a671776e25cd8827fe9d2325c#p147784

magick ../test.png  -gamma -1,-1,0  -alpha off  yellow_gamma.png

I guess this should be changed to the longer version in the doc, right?

magick ../test.png -channel red -gamma -1 -channel green -gamma -1 -channel blue -gamma 0 -alpha off yellow_gamma.png

[pgajdos]

Anyway: thank you. Gollowing have expected result after applying latest changes from git.

magick ../test.png -channel red -gamma -1 -channel green -gamma -1 -channel blue -gamma 0 -alpha off yellow_gamma.png