Good PNG Canvas for GAE but CPU/Warning

[Sylvain]

For my project, I wanted to generate a PNG image on the fly.

I found this one : Simple PNG Canvas for Python
http://the.taoofmac.com/space/Projects/PNGCanvas

It's simple and it works but even with a very simple PNG (200*200, no
gradient, etc,...), it raises a CPU warning.
So it's impossible to use even with memcache.

Is there nothing else that works on GAE (pure python) ?

Thank you

PS : if you want to test the "Simple PNG Canvas for Python" without
warnings because of a deprecated function :
- remplace this : return struct.pack("!I",len(data)) + to_check +
struct.pack("!I",zlib.crc32(to_check))
- witht : return struct.pack(">L",len(data)) + to_check +
struct.pack(">L", 0xFFFFFFFF & zlib.crc32(to_check))