I'm writing c++ image processing project using opencv. i'm calculating variance of image for each pixel. You may say variance filter. For each pixel i calculate variance around that pixel with filter size. FilterSize much smaller then image size. For that i used blurring:
blur(workingIm, blurredImage, Size(filterSize, filterSize));
blur(workingIm.mul(workingIm), blurredSqureImage, Size(filterSize, filterSize));
sqrt(blurredSqureImage - (blurredImage.mul(blurredImage)), varianceImage);
i try to improve performance using integral image. When i write loop of my own it was slower then original.
Are there any build-in opencv functions to speed up the process? Or how can i write loops that can catch opencv performance?