Abstract: A pixel-data processing circuit delivers a fixed number of pixels to a video processing stage using an irregular sampling pattern that is defined by a variably-definable sampling window. In one example embodiment directed to processing an input stream of pixels corresponding to an array of video pixels, the window size is selected from one of various options for sampling subsets of the array as a two-dimensional window that spans the pixels in the array. A sampling-window is used such that the window size is a multiple of the sampling-window size and the sampling-window size defines the fixed number of pixels.