Interesting. I noticed you mentioned below that you're trying to get rid of OpenCV as a dependency - that's really tough. I came from a Matlab background where image processing was really well-packaged and Python is a total mess.

If you managed to vendor a small portion of OpenCV that contained image i/o, basic colorspace conversion, thresholding, scaling/rotating, shape drawing/insertion, HoughLines and findContours, I think you could release that as its own package and it would be quite popular. OpenCV is such a bloated dependency...