ImageMagick generates HUGE thumbails for 24-bit PNG files with alpha channel

[v3]

Hi. I'm using imagemagick for image handling on my server.
http://img419.imageshack.us/img419/9862/image71ge7.png
When i'm trying to upload this image to my gallery, it generates ~330kb thumbail (224x400px), but original is just 191kb for 350x550px!
It can be solved if you're using "-strip -depth 8" option for PNG. Then thumb becames about 98kb. I don't think "-depth 8" is good option for every format (didn't checked, sorry), but seems like it's good to use it to handle PNG files.

I don't know, maybe it's just ImageMagick bug. Try to generate thumbs for this image using default coppermine settings.

[Nibbler]

Works fine for me. Make sure you are running an up-to-date version of ImageMagick.