+
+def grayOut(anImage):
+ """
+ Convert the given image (in place) to a grayed-out
+ version, appropriate for a 'disabled' appearance.
+ """
+ factor = 0.7 # 0 < f < 1. Higher is grayer.
+ if anImage.HasMask():
+ maskColor = (anImage.GetMaskRed(), anImage.GetMaskGreen(), anImage.GetMaskBlue())
+ else:
+ maskColor = None
+ data = map(ord, list(anImage.GetData()))
+
+ for i in range(0, len(data), 3):
+ pixel = (data[i], data[i+1], data[i+2])
+ pixel = makeGray(pixel, factor, maskColor)
+ for x in range(3):
+ data[i+x] = pixel[x]
+ anImage.SetData(''.join(map(chr, data)))
+
+
+def makeGray((r,g,b), factor, maskColor):
+ """
+ Make a pixel grayed-out. If the pixel
+ matches the maskColor, it won't be
+ changed.
+ """
+ if (r,g,b) != maskColor:
+ return map(lambda x: int((230 - x) * factor) + x, (r,g,b))
+ else:
+ return (r,g,b)