The directory arrangement of the book "OpenCV4 Quick Start" is more reasonable, starting from the basic operations of opencv step by step to advanced operations. Let you have a more systematic understanding of opencv. Instead of talking about opencv, I think it is big, messy, and complicated. I always feel that I can't get it done for a while.
Start with the basic flip filter of the image, and then do more advanced ones step by step, don't think about reaching the sky step by step.