possible bug -layers merge IM 7.0.4.5 Q16 Mac OSX

[fmw42]

It seems that -layers merge is causing a difference in creating drop shadow in IM 7.0.4.5 Q16 non-hdri compared to IM 6.9.7.5 Q16 non-hdri. The result from IM 7 has partial transparency in the main part of the image (as opposed to the shadow area) and has transparency on the top and left side of the output.

If I save the 2 images from the -shadow command and do a compare, the result is 0. So this leads me to believe it is a layer merge issue.

Input:



IM 7:

Code: Select all

magick sample.png \
\( +clone -background black -shadow 80x3+5+5 \) \
+swap -background none -layers merge +repage sample_result7.png

IM 6:

Code: Select all

convert sample.png \
\( +clone -background black -shadow 80x3+5+5 \) \
+swap -background none -layers merge +repage sample_result6.png

Animation showing difference:

[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 @ http://www.imagemagick.org/download/beta/ by sometime tomorrow.