Legacy ImageMagick Discussions Archive

IM 6.5.2-9 Q16 Mac OSX Tiger:

I don't know if this is a bug or a change in the way you deal with transparency:

This used to work in previous versions (as I recall) to convert transparent black outside the inner white to opaque red:

convert \( -size 200x200 xc:black \) \
\( -size 100x100 xc:white \) \
-gravity center -compose over -composite \
-transparent black \
-fill red -opaque none \
tmp_alpha3_red.png


But now I have to add -alpha off

convert \( -size 200x200 xc:black \) \
\( -size 100x100 xc:white \) \
-gravity center -compose over -composite \
-transparent black \
-fill red -opaque none -alpha off \
tmp_alpha4_red.png


Is this a change in the way -fill color -opaque none is supposed to work or is this related to the new -alpha background change.

(see my reply viewtopic.php?f=3&t=13843)

Add -channel rgba to your command line.

OK, this works, but I don't recall that it was necessary before. Am I not remembering correctly or has something changed?

convert \( -size 200x200 xc:black \) \
\( -size 100x100 xc:white \) \
-gravity center -compose over -composite \
-channel rgba -transparent black \
-fill red -opaque none \
tmp_alpha5_red.png