[Image-SIG] Multi-threading and PIL

[Kristofor Amundson]

Hi,

I am writing a Python script that is performing lots of pixel-based 
image comparisons and I'm using PIL's PixelAccess object to do this. In 
order to improve my performance I've attempted to multi-thread the 
pixel access using Python's threading module.

My problem is that I see little to no improvement in my performance 
with the threading, even when I process the images on a machine with 8 
CPU's. In fact, it only seems to utilize one CPU. Is this due to the 
GIL? I am wondering if there is a way for me to properly thread this to 
improve my performance. 

Thank you very much.

Kristofor Amundson