174 lines
5.7 KiB
Python
174 lines
5.7 KiB
Python
#!/usr/bin/env python
|
|
# -*- coding: iso-8859-1 -*-
|
|
|
|
import math
|
|
|
|
# from http://code.activestate.com/recipes/121574-matrix-vector-multiplication/
|
|
def matmult(m, v):
|
|
nrows = len(m)
|
|
w = [None] * nrows
|
|
for row in range(nrows):
|
|
w[row] = reduce(lambda x,y: x+y, map(lambda x,y: x*y, m[row], v))
|
|
return w
|
|
|
|
# convert H(ue) S(aturation) L(uminance) to R(ot) G(elb) B(lau)
|
|
# with S,L,R,G,B running from 0 to 1, H running from 0 to 360
|
|
# from http://en.wikipedia.org/wiki/HSL_and_HSV
|
|
def HSL2RGB(HSL):
|
|
RGB = [0.0,0.0,0.0]
|
|
H_strich = HSL[0]/60.0
|
|
c = (1.0- abs(2.0 * HSL[2] - 1.0))*HSL[1]
|
|
x = c*(1.0- abs(H_strich%2-1.0))
|
|
m = HSL[2] -.5*c
|
|
if (0.0 <= H_strich)and(H_strich<1.0):
|
|
RGB[0] = c + m
|
|
RGB[1] = x + m
|
|
RGB[2] = 0.0 + m
|
|
elif (1.0 <= H_strich)and(H_strich<2.0):
|
|
RGB[0] = x + m
|
|
RGB[1] = c + m
|
|
RGB[2] = 0.0 + m
|
|
elif (2.0 <= H_strich)and(H_strich<3.0):
|
|
RGB[0] = 0.0 + m
|
|
RGB[1] = c + m
|
|
RGB[2] = x + m
|
|
elif (3.0 <= H_strich)and(H_strich<4.0):
|
|
RGB[0] = 0.0 + m
|
|
RGB[1] = x + m
|
|
RGB[2] = c + m
|
|
elif (4.0 <= H_strich)and(H_strich<5.0):
|
|
RGB[0] = x + m
|
|
RGB[1] = 0.0 + m
|
|
RGB[2] = c + m
|
|
elif (5.0 <= H_strich)and(H_strich<=6.0):
|
|
RGB[0] = c + m
|
|
RGB[1] = 0.0 + m
|
|
RGB[2] = x + m
|
|
for i in range(3):
|
|
RGB[i] = min(RGB[i],1.0)
|
|
RGB[i] = max(RGB[i],0.0)
|
|
return RGB
|
|
|
|
# convert R(ot) G(elb) B(lau) to H(ue) S(aturation) L(uminance)
|
|
# with S,L,R,G,B running from 0 to 1, H running from 0 to 360
|
|
# from http://130.113.54.154/~monger/hsl-rgb.html
|
|
def RGB2HSL(RGB):
|
|
HSL = [0.0,0.0,0.0]
|
|
maxcolor = max(RGB)
|
|
mincolor = min(RGB)
|
|
HSL[2] = (maxcolor + mincolor)/2.0
|
|
if(mincolor == maxcolor):
|
|
HSL[0] = 0.0
|
|
HSL[1] = 0.0
|
|
else:
|
|
if (HSL[2]<0.5):
|
|
HSL[1] = (maxcolor - mincolor)/(maxcolor + mincolor)
|
|
else:
|
|
HSL[1] = (maxcolor - mincolor)/(2.0 -maxcolor -mincolor)
|
|
if (maxcolor == RGB[0]):
|
|
HSL[0] = 0.0 + (RGB[1] - RGB[2])/(maxcolor - mincolor)
|
|
elif (maxcolor == RGB[1]):
|
|
HSL[0] = 2.0 + (RGB[2] - RGB[0])/(maxcolor - mincolor)
|
|
elif (maxcolor == RGB[2]):
|
|
HSL[0] = 4.0 + (RGB[0] - RGB[1])/(maxcolor - mincolor)
|
|
HSL[0] = HSL[0]*60.0
|
|
if (HSL[0] < 0.0):
|
|
HSL[0] = HSL[0] + 360.0
|
|
for i in range(2):
|
|
HSL[i+1] = min(HSL[i+1],1.0)
|
|
HSL[i+1] = max(HSL[i+1],0.0)
|
|
return HSL
|
|
|
|
# convert R(ot) G(elb) B(lau) to CIE XYZ
|
|
# with all values in the range of 0 to 1
|
|
# from http://www.cs.rit.edu/~ncs/color/t_convert.html
|
|
def RGB2XYZ(RGB):
|
|
XYZ = [0.0,0.0,0.0]
|
|
RGB_lin = [0.0,0.0,0.0]
|
|
for i in range(3):
|
|
if (RGB[i] > 0.04045):
|
|
RGB_lin[i] = ((RGB[i]+0.0555)/1.0555)**2.4
|
|
else:
|
|
RGB_lin[i] = RGB[i]/12.92
|
|
convert =[[0.412453,0.357580,0.180423],[0.212671,0.715160,0.072169],[0.019334,0.119193,0.950227]]
|
|
XYZ = matmult(convert,RGB_lin)
|
|
for i in range(3):
|
|
XYZ[i] = min(XYZ[i],1.0)
|
|
XYZ[i] = max(XYZ[i],0.0)
|
|
return XYZ
|
|
|
|
# convert CIE XYZ R(ot) G(elb) B(lau)
|
|
# with all values in the range of 0 to 1
|
|
# from http://www.cs.rit.edu/~ncs/color/t_convert.html
|
|
def XYZ2RGB(XYZ):
|
|
RGB_lin = [0.0,0.0,0.0]
|
|
RGB = [0.0,0.0,0.0]
|
|
convert =[[3.240479,-1.537150,-0.498535],[-0.969256,1.875992,0.041556],[0.055648,-0.204043,1.057311]]
|
|
RGB_lin = matmult(convert,XYZ)
|
|
for i in range(3):
|
|
if (RGB_lin[i] > 0.0031308):
|
|
RGB[i] = ((RGB_lin[i])**(1.0/2.4))*1.0555-0.0555
|
|
else:
|
|
RGB[i] = RGB_lin[i]*12.92
|
|
for i in range(3):
|
|
RGB[i] = min(RGB[i],1.0)
|
|
RGB[i] = max(RGB[i],0.0)
|
|
return RGB
|
|
|
|
# convert CIE Lab to CIE XYZ
|
|
# with XYZ in the range of 0 to 1
|
|
# from http://en.wikipedia.org/wiki/Lab_color_space, http://www.cs.rit.edu/~ncs/color/t_convert.html
|
|
def CIELab2XYZ(Lab,white):
|
|
XYZ = [0.0,0.0,0.0]
|
|
temp = [0.0,0.0,0.0]
|
|
temp[0] = 1.0/116.0 *(Lab[0] + 16.0) + 1/500.0 * Lab[1]
|
|
temp[1] = 1.0/116.0 *(Lab[0] + 16.0)
|
|
temp[2] = 1.0/116.0 *(Lab[0] + 16.0) - 1/200.0 * Lab[2]
|
|
for i in range(3):
|
|
if (temp[i] > 6.0/29.0):
|
|
temp[i] = temp[i]**(3.0)
|
|
else:
|
|
temp[i] =3 * (6.0/29.0)**2 * (temp[i]- 4.0/29.0)
|
|
XYZ[i] = white[i] * temp[i]
|
|
for i in range(3):
|
|
XYZ[i] = min(XYZ[i],1.0)
|
|
XYZ[i] = max(XYZ[i],0.0)
|
|
return XYZ
|
|
|
|
# convert CIE XYZ to CIE Lab
|
|
# with XYZ in the range of 0 to 1
|
|
# from http://en.wikipedia.org/wiki/Lab_color_space, http://www.cs.rit.edu/~ncs/color/t_convert.html
|
|
def XYZ2CIELab(XYZ,white):
|
|
temp = [0.0,0.0,0.0]
|
|
Lab = [0.0,0.0,0.0]
|
|
for i in range(3):
|
|
temp[i] = XYZ[i]/white[i]
|
|
if (temp[i] > (6.0/29.0)**3.0):
|
|
temp[i] = temp[i]**(1.0/3.0)
|
|
else:
|
|
temp[i] = 1.0/3.0 * (29.0/6.0)**2.0 * temp[i] + 4.0/29.0
|
|
Lab[0] = 116.0 * temp[1] - 16.0
|
|
Lab[1] = 500.0 *(temp[0] - temp[1])
|
|
Lab[2] = 200.0 *(temp[1] - temp[2])
|
|
return Lab
|
|
|
|
# convert Cie Lab to msh colorspace
|
|
# from http://www.cs.unm.edu/~kmorel/documents/ColorMaps/DivergingColorMapWorkshop.xls
|
|
def CIELab2Msh(Lab):
|
|
Msh = [0.0,0.0,0.0]
|
|
Msh[0] = math.sqrt(Lab[0]**2.0 + Lab[1]**2.0 + Lab[2]**2.0)
|
|
if (Msh[0] != 0.0):
|
|
Msh[1] = math.acos(Lab[0]/Msh[0])
|
|
if (Lab[1] != 0.0):
|
|
Msh[2] = math.atan2(Lab[2],Lab[1])
|
|
return Msh
|
|
|
|
# convert msh colorspace to Cie Lab
|
|
# from http://www.cs.unm.edu/~kmorel/documents/ColorMaps/DivergingColorMapWorkshop.xls
|
|
def Msh2CIELab(Msh):
|
|
Lab = [0.0,0.0,0.0]
|
|
Lab[0] = Msh[0] * math.cos(Msh[1])
|
|
Lab[1] = Msh[0] * math.sin(Msh[1]) * math.cos(Msh[2])
|
|
Lab[2] = Msh[0] * math.sin(Msh[1]) * math.sin(Msh[2])
|
|
return Lab
|