Learn OpenCV 4 by Building Projects - Second Edition

Basic matrix operations

In this section, we will learn a number of basic and important matrix operations that we can apply to images or any matrix data. We learned how to load an image and store it in a Mat variable, but we can create Mat manually. The most common constructor is giving the matrix a size and type, as follows:

Mat a= Mat(Size(5,5), CV_32F); 

You can create a new matrix linking with a stored buffer from third-party libraries without copying data using this constructor: Mat(size, type, pointer_to_buffer).

The types supported depend on the type of number you want to store and the number of channels. The most common types are as follows:

CV_8UC1 
CV_8UC3 
CV_8UC4 
CV_32FC1 
CV_32FC3 
CV_32FC4

You can create any type of matrix using ...