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