I am not an expert on this, but I am not sure that IM treats the alpha channel the same as the others. So if you have a 4 channel multispectral image, telling it that it is rgba may not work (and I don't think prefacing it with rgba: is meaningful in IM, but I could be wrong). Also I don't think jp2 (like jpg) may not support alpha, so try converting to png that does support alpha channels
try to separate all the channels and then possibly put the 4th channel back as a an alpha channel, if they separate and look good try the following: convert test.jp2 -channel rgba -matte test.png does that work, if not then try separating channels (see http://www.imagemagick.org/Usage/channels/#channels convert test.jp2 -separate test_%d.png then combine any 3 together to view as RGB. You might be able to trick IM into thinking the 4 channels are CMYK. convert test.jp2 -set colorspace CMYK test.jpg but then I am not sure what to do after that or what the result might be. But you could then convert to RGB, but then you will have changed from 4 channels to 3 and colorspaces as well. Fred _______________________________________________ Magick-users mailing list [email protected] http://studio.imagemagick.org/mailman/listinfo/magick-users
