Image processing operations

When you write a computer vision algorithm, there are a lot of basic image processing operations that you will use over and over again. Most of these functions are present in the imgproc module. You can do things such as image filtering, morphological operations, geometric transformations, color conversions, drawing on images, histograms, shape analysis, motion analysis, feature detection, and more.

Let's consider the following photo:

The right image is a rotated version of the one on the left. We can carry out this transformation with a single line in OpenCV.

There is another module, called ximgproc, which contains advanced image processing algorithms such as structured forests for edge detection, domain transform filter, adaptive manifold filter, and so on.