Systems, methods, and computer readable media to categorize a pixel (or other element) in an image into one of a number of different categories are described. In general, techniques are disclosed for using properties (e.g., statistics) of the regions being categorized to determine the appropriate size of window around a target pixel (element) and, when necessary, the manner in which the window may be changed if the current size is inappropriate. More particularly, adaptive window size selection techniques are disclosed for use when categorizing an image's pixels into one of two categories (e.g., black or white). Statistics of the selected region may be cascaded to determine whether the current evaluation window is acceptable and, if it is not, an appropriate factor by which to change the currently selected window's size.