def tint(self, tint='#ffffff'):
self.open()
src = self.img
if src.mode not in ['RGB', 'RGBA']:
raise TypeError('Unsupported source image mode: {}'.format(src.mode))
src.load()
if type(tint) in [str, unicode]:
tr, tg, tb = getrgb(tint)
tl = getcolor(tint, "L") # tint color's overall luminosity
else:
tr, tg, tb = tint
tl = sum([tr,tg,tb])/3
if not tl: tl = 1 # avoid division by zero
tl = float(tl) # compute luminosity preserving tint factors
sr, sg, sb = map(lambda tv: tv/tl, (tr, tg, tb)) # per component adjustments
# create look-up tables to map luminosity to adjusted tint
# (using floating-point math only to compute table)
luts = (map(lambda lr: int(lr*sr + 0.5), range(256)) +
map(lambda lg: int(lg*sg + 0.5), range(256)) +
map(lambda lb: int(lb*sb + 0.5), range(256)))
l = grayscale(src) # 8-bit luminosity version of whole image
if Image.getmodebands(src.mode) < 4:
merge_args = (src.mode, (l, l, l)) # for RGB verion of grayscale
else: # include copy of src image's alpha layer
a = Image.new("L", src.size)
a.putdata(src.getdata(3))
merge_args = (src.mode, (l, l, l, a)) # for RGBA verion of grayscale
luts += range(256) # for 1:1 mapping of copied alpha values
self.img = Image.merge(*merge_args).point(luts)
self.save()
self.close()
def image_tint(src, tint='#ffffff'):
if Image.isStringType(src): # file path?
src = Image.open(src)
if src.mode not in ['RGB', 'RGBA']:
raise TypeError('Unsupported source image mode: {}'.format(src.mode))
src.load()
tr, tg, tb = getrgb(tint)
tl = getcolor(tint, "L") # tint color's overall luminosity
if not tl: tl = 1 # avoid division by zero
tl = float(tl) # compute luminosity preserving tint factors
sr, sg, sb = map(lambda tv: tv / tl,
(tr, tg, tb)) # per component adjustments
# create look-up tables to map luminosity to adjusted tint
# (using floating-point math only to compute table)
luts = (map(lambda lr: int(lr * sr + 0.5), range(256)) +
map(lambda lg: int(lg * sg + 0.5), range(256)) +
map(lambda lb: int(lb * sb + 0.5), range(256)))
l = grayscale(src) # 8-bit luminosity version of whole image
if Image.getmodebands(src.mode) < 4:
merge_args = (src.mode, (l, l, l)) # for RGB verion of grayscale
else: # include copy of src image's alpha layer
a = Image.new("L", src.size)
a.putdata(src.getdata(3))
merge_args = (src.mode, (l, l, l, a)) # for RGBA verion of grayscale
luts += range(256) # for 1:1 mapping of copied alpha values
return Image.merge(*merge_args).point(luts)
