I am new at DMIP programming and I have a question about the way graphs work. I want to perform several thresholdings to an image using the MinVal function. I noticed that using the same graph in the code below for the second operation, the second operation does not work. After I added Release() to the graph before the second operation, then it works fine. Could anybody explain me why this happens?
Image *iMag //e.g. the Sobel magnitude
graph = MinVal( *iMag, (Scalar)2, 4);
graph = MinVal( *iMag, (Scalar)-1, 4);