I used OpenCV for the first time around 2 years ago, and I asked one of my professors if he had a good CV text I could use to quickly learn the basic techniques. The book was from the late 90s, but the algorithms it covered were basically the same as those in the OpenCV API. It was quite surprising to me that not much had been added to the state-of-the-art since the publication of the textbook.

For those curious, I was writing some code for 2D object distance estimation for use in a undergrad robotics competition. My team ended up losing, but I think we could have done better had I not started reading up on CV and writing code only a week before the deadline. I'm surprised we were able to even get past the first round!