Machine Learning for OpenCV 4 - Second Edition

Getting a glimpse of OpenCV's ml module

Starting with OpenCV 3.1, all machine learning related functions in OpenCV have been grouped into the ml module. This has been the case for the C++ API for quite some time. You can get a glimpse of what's to come by displaying all functions in the ml module:

In [4]: dir(cv2.ml)Out[4]: ['ANN_MLP_ANNEAL', 'ANN_MLP_BACKPROP', 'ANN_MLP_GAUSSIAN', 'ANN_MLP_IDENTITY', 'ANN_MLP_LEAKYRELU', 'ANN_MLP_NO_INPUT_SCALE', 'ANN_MLP_NO_OUTPUT_SCALE', ... '__spec__']

If you have installed an older version of OpenCV, the ml module might not be present. For example, the k-nearest neighbor algorithm (which we will talk about in Chapter 3, First Steps in Supervised Learning) used to be called cv2.KNearest() but is now called ...