0 : bidimensional form 1 : form for horizontal lines single-channel picture to analyse. the content must be made of zeroes and ones (other values are reserved for making the output) single-channel picture in which every contiguous region (of ones) is labelled (flood-filled) using a number greater than or equal to 2 those numbers are sorted according to the smallest pixel index found in each region. when form=0: a grid[2] giving the centre ([#moment 1]) of each region when form=0: area of each region (in number of pixels) when form=1: not present when form=1: not present when form=1: a grid[2, 2] that is a 2-polygon, that is, just a straight line. this line is horizontal, and its right-side bound is for the first pixel that is NOT in the region. when form=0: a grid[2, 2] giving the variance (centred [#moment 2]) of each region make one channel of red minus green minus blue Flood-fill every "1" region of a picture using a different number, and make stats about it. select negative regions (R < G+B) generate various colours from the region numbers