Hey, this is great :) I attempted to do something similar a while back https://github.com/aadv1k/deimos basically trying to build many of OpenCV's functions from scratch in C from first principles, though I was using stb for handling the images. I ended up putting the project on hold, primarily because I lost interest in computer vision at the time.

For a while I went deep into OCR, and built a rather rudimentary stroke width transform (https://github.com/aadv1k/swt.h) but again, the results were very hit or miss, likely because I never took the time to understand the logic behind why these functions would work.

1) Optimise many of the functions (a lot of room to use GPU, multi-threading and what not!). 2) Add new functions and improve the existing edge detection ones

I would love to know of a good resource for computer vision, the various algorithms, optimisation techniques etc. Thanks for sharing this project! Cheers