Most programs that we have worked with as part of this book followed a specific pattern. We gave the computer detailed instructions on how to operate on input data (mostly images in our case), and our algorithm diligently followed our instructions to generate the output (which could have been an image or a sequence of values as in the case of a histogram). For example, let's consider image filtering covered in Chapter 2, Image Filtering. We call the OpenCV function, filter2D(), with the appropriate parameters. The implementation of filter2D() holds the detailed instructions to perform image filtering, that is, it consists of the logic to traverse through all the pixels in the image and perform the correlation operation at each pixel location. Everything, including the input image and the filter parameters, is provided to the algorithm. It simply follows the instructions and generates the output image.
In fact, this is how programs were written for a long time. The...
