----------------------------Original message---------------------------- This message has been cross-posted to MAPS-L and MapHist. My apologies to those people who subscribe to both. I would like to know if anyone has come across a scheme to classify maps based on the number of colours present in them. That is, I am not interested in classifications based on the intellectual content (eg., topo map, thematic map, cadastral survey, etc.) but rather on the physical attributes of the picture itself, such as colour, line widths and letter sizes. For example, an outline map of North America would likely be in 2 colour, black and white, with maybe 2 line widths and 1 or 2 sizes of letters while a topograhpic map would have 8-10 colours, several line widths, and several sizes of text, and a satellite image of North America would likely be a continuous tone image, with myriad subtle shades, etc. Is there a classification scheme that would separate these images based on these attributes? Thanks folks.... P. Andrew Ray Department of Geography University of Western Ontario <[log in to unmask]>