97 lines
3.3 KiB
Python
97 lines
3.3 KiB
Python
from PIL import Image
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def getErr(r,g,b,stdCol):
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r-=stdCol[0]
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g-=stdCol[1]
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b-=stdCol[2]
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return r*r + g*g + b*b
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def getNear(r,g,b, curPal):
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ind=0
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err=getErr(r,g,b,curPal[0])
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for i in range(1,len(curPal)):
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cur=getErr(r,g,b,curPal[i])
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if (cur<err):
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err=cur
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ind=i
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return ind
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def addVal(c,r,g,b,k):
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return[c[0]+(r*k)/32,c[1]+(g*k)/32,c[2]+(b*k)/32]
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def procImg(img, dW, dH, dX, dY, palInd, isLvl, isRed, palArr):
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if isRed and ((palInd & 1) == 0):
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raise ValueError('This white-black display')
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if not isRed:
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palInd = palInd & 0xFE
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curPal = palArr[palInd]
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sW = img.width
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sH = img.height
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pDst = Image.new('RGB', (dW, dH))
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pixels = pDst.load()
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if isLvl:
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# Level-based processing
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for j in range(dH):
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y = dY + j
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for i in range(dW):
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x = dX + i
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if 0 <= x < sW and 0 <= y < sH:
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r, g, b = img.getpixel((x, y))
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color_index = getNear(r, g, b, curPal)
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pixels[i, j] = tuple(curPal[color_index])
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else:
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pixels[i, j] = tuple(curPal[(i + j) % 2]) # checkerboard for out of bounds
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else:
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# Dithering
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errArr = [[[0, 0, 0] for _ in range(dW)] for _ in range(2)]
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aInd = 0
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bInd = 1
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for j in range(dH):
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y = dY + j
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aInd, bInd = bInd, aInd # swap buffers
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for i in range(dW):
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errArr[bInd][i] = [0,0,0]
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for i in range(dW):
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x = dX + i
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if 0 <= x < sW and 0 <= y < sH:
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old = errArr[aInd][i]
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r_orig, g_orig, b_orig = img.getpixel((x, y))
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r = r_orig + old[0]
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g = g_orig + old[1]
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b = b_orig + old[2]
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color_index = getNear(r, g, b, curPal)
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colVal = curPal[color_index]
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pixels[i, j] = tuple(colVal)
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r_err = r - colVal[0]
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g_err = g - colVal[1]
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b_err = b - colVal[2]
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# Propagate error (Floyd-Steinberg-like)
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if i == 0:
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errArr[bInd][i] = addVal(errArr[bInd][i], r_err, g_err, b_err, 7.0)
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if dW > 1:
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errArr[bInd][i+1] = addVal(errArr[bInd][i+1], r_err, g_err, b_err, 2.0)
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errArr[aInd][i+1] = addVal(errArr[aInd][i+1], r_err, g_err, b_err, 7.0)
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elif i == dW - 1:
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errArr[bInd][i-1] = addVal(errArr[bInd][i-1], r_err, g_err, b_err, 7.0)
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errArr[bInd][i] = addVal(errArr[bInd][i], r_err, g_err, b_err, 9.0)
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else:
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errArr[bInd][i-1] = addVal(errArr[bInd][i-1], r_err, g_err, b_err, 3.0)
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errArr[bInd][i] = addVal(errArr[bInd][i], r_err, g_err, b_err, 5.0)
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errArr[bInd][i+1] = addVal(errArr[bInd][i+1], r_err, g_err, b_err, 1.0)
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errArr[aInd][i+1] = addVal(errArr[aInd][i+1], r_err, g_err, b_err, 7.0)
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else:
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pixels[i, j] = tuple(curPal[(i + j) % 2]) # checkerboard
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return pDst
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