UnknownColormap="UnknownColormap"

import os.path
import Image, ImagePalette
import numpy

class ColorTable:

    def __init__(self, colormap = None):
        self.colormap = colormap
        if colormap != None:
            self.load(colormap)

    def get_palette(self,colormap=""):
        """
        Returns a string representation of the colormap, as used with a PIL image
        @param colormap the name of the colormap to use. If not defined, throws an "UnknownColormap" exception
        """       

        if(self.colormap != colormap):
            self.load(colormap)

        return self.palette

    def get_length(self,colormap=""):

        if(self.colormap != colormap):
            self.load(colormap)

        return self.length

    def load(self, colormap):
        """Load the palette with colormap"""
                
        lutfile = os.path.join ( os.path.dirname ( __file__ ), "color_LUT", colormap+".pal" )
        if not os.path.exists(lutfile) :
            lutfile = os.path.join ( os.path.dirname ( __file__ ), "color_LUT", colormap )
        if not os.path.exists(lutfile) :
            lutfile = colormap
        if not os.path.exists(lutfile) :
            if not os.path.exists(lutfile) :
                raise UnknownColormap, colormap 

        self.length = 0
        fh = open(lutfile, "r")
        self.palette=[]
        for line in fh.xreadlines():
            RGB = line.split()
            self.palette.extend((int(RGB[0]), int(RGB[1]), int(RGB[2])))
            self.length += 1
        fh.close()         

    def save(self, colormap):
        """Saves the palette under name colormap"""
        lutfile = os.path.join ( ".","color_LUT",colormap+".pal" )
        print 'saving palette '+lutfile   
        print self.palette     
        fh = open(lutfile, "w")
        for r, g, b in self.palette:
            line = str(r)+" "+str(g)+" "+str(b)+'\n'
            fh.write(line)       
        fh.close()

    def get_Palette_from_image(self,colormap,filename):
        """
        """
        image = Image.open(filename, 'r')
        pal = image.palette
        
        assert image.mode == "P"

        lut = image.resize((256, 1))
        lut.putdata(range(256))
        lut = list(lut.convert("RGB").getdata())

        pal = lut

        self.palette = pal

        self.save(colormap)
        

def main():
    ct = ColorTable(None)
    ct.get_Palette_from_image(sys.argv[1],sys.argv[2])

if __name__ == '__main__':
    main()