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Revision as of 04:28, 7 April 2004 editChinasaur (talk | contribs)Extended confirmed users3,353 edits Did my best to touch things up for HSV. Dunno Py, so may need tweaking to get it to run.← Previous edit Latest revision as of 15:49, 8 May 2022 edit undoQwerfjkl (bot) (talk | contribs)Bots, Mass message senders4,012,477 editsm →top: Replaced deprecated <source> tags with <syntaxhighlight>Tag: AWB 
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<pre>


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



# Diclaimer: # Diclaimer:
# I only just picked up python. No apologies are made for this code. # 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) : def hextriplet2rgb(triplet) :
# assuming the triplet *isn't* prefixed with 0x value=int(triplet, 16)
value=eval("0x"+triplet)
r=(value & 0xFF0000) / 0x10000 r=(value & 0xFF0000) / 0x10000
g=(value & 0x00FF00) / 0x100 g=(value & 0x00FF00) / 0x100
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MIN=min(r,g,b) MIN=min(r,g,b)


# Using negatives for this generally not a good idea. In most # Using a "undefined" instead of None
# languages, you'd want to use a special value like "undef" or # because we want encyclopedic style output
h="undefined" #default
# "null". I think Python has "none" but I don't know Python so
s="undefined" #default
# I'm not sure if that's what you'd use.
# Especially not a good idea in this case since h is actually supposed
# to be able to go negative (see below and my new revision to the
# HSV color space article.
# And anyway, using the else statement is a better way to arrange the
# logic. Easier to read, and one less comparison so probably more
⚫ # efficient.
⚫ # h=-1
⚫ # s=-1


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


if (s > 0) : if s > 0 and s != "undefined" :
if r == MAX: h=(0.0+( (g-b)/(MAX-MIN) ))*60 if r == MAX: h=(0.0+( (g-b)/(MAX-MIN) ))*60

# This was wrong in the article; reversed the minus
if g == MAX: h=(2.0+( (b-r)/(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 if b == MAX: h=(4.0+( (r-g)/(MAX-MIN) ))*60
# Actually h should be undefined in this case; you might want to
# set it to "none" if that's the way Python works. In practice
# there's nothing wrong with making it zero though.
⚫ else: h = 0

⚫ H=int(h)
⚫ S=int(s*100)
V=int(v*100)
⚫ # Format
# H will intentionally come out < 0 for purples; have to wrap around
# if H<0: H="undefined"
if H < 0: H += 360 H=h
⚫ if h != "undefined" :

# Shouldn't be possible for S < 0; at most throw an error here but if h < 0: h+=360
# I'd just cut it. H=int(round(h))
# if S<0: S="undefined" S=s
⚫ if s!= "undefined" : S=int(round(s*100))

⚫
⚫ V=int(round(v*100))
⚫
return (H,S,V) return (H,S,V)


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</syntaxhighlight>
</pre>

Latest revision as of 15:49, 8 May 2022

> example run 

#!/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) :
        value=int(triplet, 16)
        r=(value & 0xFF0000) / 0x10000
        g=(value & 0x00FF00) /   0x100
        b=(value & 0x0000FF) 
        return (r,g,b)
# from http://en.wikipedia.org/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), ))
# from http://en.wikipedia.org/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(" \'\'\']\'\'\' = #")
        rgb=hextriplet2rgb(hextriplet)
        print " \'\'\']\'\'\'    (r, g, b)    = ",rgb
        print " \'\'\']\'\'\'   (c, m, y, k) = ",rgb2cmyk(rgb)
        print " \'\'\']\'\'\'    (h, s, v)    = ",rgb2hsv(rgb)