OpenCV has many algorithms covering the same subject. When implementing a new processing pipeline, sometimes there is more than one choice for a step in the pipeline. For example, in Chapter 14, Explore Structure from Motion with the SfM Module, we made an arbitrary decision to use AKAZE features for finding landmarks between the images to estimate camera motion, and sparse 3D structure, however; there are many more kinds of 2D features available in OpenCV's features2D module. A more sensible mode of operation should have been to select the type of feature algorithm to use based on its performance, with respect to our needs. At the very least, we need to be aware of the different options.
Again, we looked to create a convenient way to see whether there are multiple options for the same task. We created a table where we list specific computer vision tasks that have multiple algorithm implementations in OpenCV. We also strived to mark whether algorithms have a common...