The Laplacian is another high-pass linear filter that is based on the computation of the image derivatives. As it will be explained, it computes second-order derivatives to measure the curvature of the image function.
The OpenCV function
cv::Laplacian computes the Laplacian of an image. It is very similar to the
cv::Sobel function. In fact, it uses the same basic function
cv::getDerivKernels in order to obtain its kernel matrix. The only difference is that there is no derivative order parameters since these ones are by definition second order derivatives.
For this operator, we will create a simple class that will encapsulate some useful operations related to the Laplacian. The basic methods are: ...