Coalesce introduces random background colors

[abxccd]

I am trying to run coalesce on this image (animated gif with transparent background):


If I run the following command:

Code: Select all

convert beaver.gif -coalesce temporary.gif

The result is that that parts of the frames are filled up with a random background color:

[fmw42]

I do not think this is a bug. It was answered at viewtopic.php?f=1&t=24684. You need to define the background when creating a new animation.