See also

• The Performing simple image arithmetic recipe presents an implementation of the color reduction function (described in the There's more... section) that uses the OpenCV 2 arithmetic image operators and has a runtime of 53 ms.

• The Applying look-up tables to modify image appearance recipe of Chapter 4, Counting the Pixels with Histograms, describes an implementation of the color reduction function based on a lookup table. The idea is to precompute all intensity reduction values that lead to a runtime of 29 ms.

We've successfully learned how to write efficient image-scanning loops. Now let's move on to the next recipe!