[Haskell-cafe] How to devide matrix into small blocks

Hi all: I already have one matrix of type [[a]] to store one image. What I want to do is to devide the image into severial small blocks in same size. To do that, I wrote this tool function. chop :: Int -> [a] -> [[a]] chop _ [] = [] chop n ls = take n ls : chop n (drop n ls) But I do not know how to use it to write the function. Thanks for any advice. Regards -------------- L.Guo 2007-06-13