Alpha bug with 7.0.10-53

[GeeMack]

ImageMagick 7.0.10-53 Q16 x64 HDRI on Windows 10.

When I run this command...

magick rose: -bordercolor %[pixel:p{20,20}] -border 12 result.png

I get this result, as I would expect, the rose image with a border of the color of the pixel at location x20 y20.

I've come across a problem with v7.0.10-53 when I do anything that adds an alpha channel. By appending a transparent pixel to the rose image with this command...

magick rose: xc:none +append -bordercolor %[pixel:p{20,20}] -border 12 result.png

The result has a transparent border instead of the red border expected.

This transparent effect happens in any case where I use "%[pixel:p{x,y}]" to acquire a color and apply it to any image with an alpha channel. I don't know when this issue first appeared, but it did not occur in version 7.0.10-44 or before.

[dlemstra]

It looks like this was broken due to this commit: 3ba4863. The problem can also be reproduced with:
magick -size 100x100 xc:srgba(169,59,42,1) result.png. Due to that change it now expects the alpha value to be in the quantum range, where 1 is almost transparent. We will need to investigate this futher.

[urban-warrior]

hanks for the problem report. We can reproduce it and will have a patch to fix it in the 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.

[GeeMack]

The issues associated with this bug seem to be corrected in version ImageMagick 7.0.10-54 Q16 x64. Thanks!