roberto, I don't know the answer to your question, but www.imagemagick.org has a lot of resources.

There's a number of examples and discussions available, and searching the bug tracking system for some of your keywords may find sample code that people have posted to demonstrate a problem (pay close attention to the bug searching process. It spits out partial pages, and is not always evident whether it's completed or not. Make sure the browser indicates it's done before assuming the search did not complete).

You might also check what revision you have installed. I found a pretty glaring bug in the 5.2.2 release pertaining to color to monochrome conversion, and a lot of people had problems with format conversion. It would be my last resort, but don't *completely* discount a ImageMagick bug, especially in the 5.2.2 release.

Also, if you have the ImageMagick tarball installed, I believe there is a directory that contains some various examples that may be worth looking at.

I do know from the little I've done with ImageMagick that transparent layers always seem to be a pain. I don't know enough general behavior about them to say 'Oh, you need to do this'.

--Chris

e-mail jcwren