Warrick FitzGerald on wrote... | Hi All, | | Im trying to reduce the number of colors using a ColorMap image and | getting some very strange results when using a colormap. | | Source Image: http://206.65.169.164/~wfitzgerald/G1.tif | | # This seems to work fine. | convert G1.tif -colors 64 G1_Converted.gif | | Result: http://206.65.169.164/~wfitzgerald/G1_Converted.gif | | # This does not | convert G1.tif -colors 64 -unique-colors G1_map.gif | convert G1.tif -map G1_map.gif G1_converted_using_map.gif | | Result: http://206.65.169.164/~wfitzgerald/G1_converted_using_map.gif | The map File: http://206.65.169.164/~wfitzgerald/G1_map.gif |
PROBLEM VERIFIED on a IM only a couple of days old. No matte channel involvement for semi-transparency colors :-( Can't see a color depth problem (see last test below) It is NOT purely a -unique-color map problem, but only seems to happen when BOTH -unique-color and GIF file format is involved. The desired colormap is VERY different from the resuling color map This is a definate error as the -unique-color image has changed! However it also appears on MIFF: saves, and MIFF is supossed to preserve all in memory parameters of the image! ------------- Summery... wget http://206.65.169.164/~wfitzgerald/G1.tif convert G1.tif -colors 64 gif:- | identify -format %k - 64 Good, but use unique colors (with a save to GIF) and we get... convert G1.tif -colors 64 -unique-colors gif:- | identify -format %k - 16 This is clearly an ERROR, and will produce problems with color map generation, especially for animation handling. Without the save to GIF we also get 64 colors... convert G1.tif -colors 64 -unique-colors -format %k info: 64 Using txt at different depths also shows no problem... convert G1.tif -colors 64 -unique-colors txt:- | identify -format %k - 64 convert G1.tif -colors 64 -unique-colors -depth 8 txt:- |\ identify -format %k - 64 Looking at the colors... convert G1.tif -colors 64 -unique-colors -depth 8 txt:- |\ convert - -scale 1000% x: & convert G1.tif -colors 64 -unique-colors gif:- |\ convert - -scale 1000% x: & The two resulting images are very different with LOTS of the original colors lost in the save to GIF format! <------ THE ERROR Seperating the functions... convert G1.tif -colors 64 -unique-colors -depth 8 txt:- |\ convert - gif:- | identify -format %k - 64 Now I get a 64 color GIF of unique colors!!! What was originally wanted! STOP PRESS.... It re-appears for the IM's internal MIFF: format!!!! convert G1.tif -colors 64 -unique-colors miff:- | identify -format %k - 16 Now that is WIERD!!! MIFF header even declares the image to have 64 colors. =======8<-------- id=ImageMagick version=1.0 class=PseudoClass colors=64 matte=False columns=64 rows=1 depth=16 colorspace=RGB compression=None quality=0 units=PixelsPerInch resolution=72x72 page=64x1+0+0 orientation=TopLeft Software={Adobe Photoshop CS Windows} Timestamp={2007:03:11 16:31:34} =======8<-------- Anthony Thyssen ( System Programmer ) <[EMAIL PROTECTED]> ----------------------------------------------------------------------------- Please miss, can I leave? My brain is full! ----------------------------------------------------------------------------- Anthony's Home is his Castle http://www.cit.gu.edu.au/~anthony/ _______________________________________________ Magick-users mailing list [email protected] http://studio.imagemagick.org/mailman/listinfo/magick-users
