User:Kim Bruning/colorspace.py

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#!/usr/bin/python
# colorspace.py
# calculates RGB, CMYK and HSV values from a hex triplet


# Diclaimer: 
# I only just picked up python. No apologies are made for this code.
# Dysprosia and Chinasaur helped with formulas for CMYK and HSV respectively

def hextriplet2rgb(triplet) :
        # assuming the triplet *isn't* prefixed with 0x
        value=eval("0x"+triplet)
        r=(value & 0xFF0000) / 0x10000
        g=(value & 0x00FF00) /   0x100
        b=(value & 0x0000FF) 
        return (r,g,b)


# from http://en.wikipedia.org/wiki/CMYK
def rgb2cmyk (rgb) :
        r,g,b=rgb
        c,m,y=(1 - r / 255.0,1 - g / 255.0,1 - b / 255.0)
        C,M,Y,K= (c-min(c,m,y),m-min(c,m,y),y-min(c,m,y),min(c,m,y))
        # and additionally, *255 to convert proportion up to 8bits
        return tuple(map (lambda proportion: int(proportion*255), [C,M,Y,K]))

# from http://en.wikipedia.org/wiki/HSV_color_space
def rgb2hsv (rgb) :
        # formula takes fp, bother!
        r,g,b = map (lambda x : x/255.0, rgb)
        MAX=max(r,g,b)
        MIN=min(r,g,b)

        # Using a "undefined" instead of None 
        # because we want encyclopedic style output
        h="undefined" #default
        s="undefined" #default

        v=MAX
        
        if (v > 0) :
                s = (MAX - MIN) / MAX 

        if (s > 0 and s != "undefined" ):
                if r == MAX: h=(0.0+( (g-b)/(MAX-MIN) ))*60
                if g == MAX: h=(2.0+( (b-r)/(MAX-MIN) ))*60
                if b == MAX: h=(4.0+( (r-g)/(MAX-MIN) ))*60
        
        # Format
        
        H=h
        if ( h != "undefined" ):
                if h < 0: h+=360
                H=int(round(h))
        S=s
        if (s!= "undefined") : S=int(round(s*100))
        
        V=int(round(v*100))
        
        return (H,S,V)

while True:
        print "\n\n"
        print "== Color Coordinates =="
        hextriplet = raw_input(" \'\'\'[[Hex triplet]]\'\'\' = #")
        rgb=hextriplet2rgb(hextriplet)
        print " \'\'\'[[RGB]]\'\'\'    (r, g, b)    = ",rgb
        print " \'\'\'[[CMYK]]\'\'\'   (c, m, y, k) = ",rgb2cmyk(rgb)
        print " \'\'\'[[HSV color space|HSV]]\'\'\'    (h, s, v)    = ",rgb2hsv(rgb)