Hello all. I have large 600 DPI colour scans that I would like to convert to compact PNG. To let PNG do its work, the number of colours needs to be reduced.
The document lends itself to quantisation very well ; it is typeset text with some orange highlighter so the scan contains only black, white and shades of fluorescent orange and grey. It could be adequately rendered with just, say, 8 colours : black, white, 3 greys and 3 shades of orange. Unfortunately, convert's native quantisation does not work that well with it. I end up with either too many shades of light grey for good compression or light brown instead of orange. I would like the quantiser to pick something along the lines of #000 #444 #888 #ccc #FFF for the greys and #FF9840 #804c20 #402610 for the oranges. Some scaling would be required, as the thresholds for logical black and white are maybe #333 and #ddd in the original. Normalisation cannot be used because many pixels have at least one component set to 0xFF. How would you approach this ? -- André Majorel <URL:http://www.teaser.fr/~amajorel/> Do not use this account for regular correspondence. See the URL above for contact information. _______________________________________________ Magick-users mailing list [email protected] http://studio.imagemagick.org/mailman/listinfo/magick-users
