def _make_transparent(img, color, tolerance=10):
img.load()
if img.mode == 'P':
img = img.convert('RGBA')
channels = img.split()
mask_channels = []
for ch, c in zip(channels, color):
# create bit mask for each matched color
low_c, high_c = c - tolerance, c + tolerance
mask_channels.append(
Image.eval(ch, lambda x: 255 if low_c <= x <= high_c else 0))
# multiply channel bit masks to get a single mask
alpha = reduce(ImageChops.multiply, mask_channels)
# invert to get alpha channel
alpha = ImageChops.invert(alpha)
if len(channels) == 4:
# multiply with existing alpha
alpha = ImageChops.multiply(alpha, channels[-1])
img.putalpha(alpha)
return img
def _make_transparent(img, color, tolerance=10):
img.load()
if img.mode == 'P':
img = img.convert('RGBA')
channels = img.split()
mask_channels = []
for ch, c in zip(channels, color):
# create bit mask for each matched color
low_c, high_c = c-tolerance, c+tolerance
mask_channels.append(Image.eval(ch, lambda x: 255 if low_c <= x <= high_c else 0))
# multiply channel bit masks to get a single mask
alpha = reduce(ImageChops.multiply, mask_channels)
# invert to get alpha channel
alpha = ImageChops.invert(alpha)
if len(channels) == 4:
# multiply with existing alpha
alpha = ImageChops.multiply(alpha, channels[-1])
img.putalpha(alpha)
return img
def merge(self, image_opts, size=None, bbox=None, bbox_srs=None, coverage=None):
"""
Merge the layers. If the format is not 'png' just return the last image.
:param format: The image format for the result.
:param size: The size for the merged output.
:rtype: `ImageSource`
"""
if not self.layers:
return BlankImageSource(size=size, image_opts=image_opts, cacheable=True)
if len(self.layers) == 1:
layer_img, layer = self.layers[0]
layer_opts = layer_img.image_opts
if (((layer_opts and not layer_opts.transparent) or image_opts.transparent)
and (not size or size == layer_img.size)
and (not layer or not layer.coverage or not layer.coverage.clip)
and not coverage):
# layer is opaque, no need to make transparent or add bgcolor
return layer_img
if size is None:
size = self.layers[0][0].size
cacheable = self.cacheable
result = create_image(size, image_opts)
for layer_img, layer in self.layers:
if not layer_img.cacheable:
cacheable = False
img = layer_img.as_image()
layer_image_opts = layer_img.image_opts
if layer_image_opts is None:
opacity = None
else:
opacity = layer_image_opts.opacity
if layer and layer.coverage and layer.coverage.clip:
img = mask_image(img, bbox, bbox_srs, layer.coverage)
if result.mode != 'RGBA':
merge_composite = False
else:
merge_composite = has_alpha_composite_support()
if merge_composite:
if opacity is not None and opacity < 1.0:
# fade-out img to add opacity value
img = img.convert("RGBA")
alpha = img.split()[3]
alpha = ImageChops.multiply(
alpha,
ImageChops.constant(alpha, int(255 * opacity))
)
img.putalpha(alpha)
if img.mode in ('RGBA', 'P'):
# assume paletted images have transparency
if img.mode == 'P':
img = img.convert('RGBA')
result = Image.alpha_composite(result, img)
else:
result.paste(img, (0, 0))
else:
if opacity is not None and opacity < 1.0:
img = img.convert(result.mode)
result = Image.blend(result, img, layer_image_opts.opacity)
elif img.mode in ('RGBA', 'P'):
# assume paletted images have transparency
if img.mode == 'P':
img = img.convert('RGBA')
# paste w transparency mask from layer
result.paste(img, (0, 0), img)
else:
result.paste(img, (0, 0))
# apply global clip coverage
if coverage:
bg = create_image(size, image_opts)
mask = mask_image(result, bbox, bbox_srs, coverage)
bg.paste(result, (0, 0), mask)
result = bg
return ImageSource(result, size=size, image_opts=image_opts, cacheable=cacheable)
def merge(self,
image_opts,
size=None,
bbox=None,
bbox_srs=None,
coverage=None):
"""
Merge the layers. If the format is not 'png' just return the last image.
:param format: The image format for the result.
:param size: The size for the merged output.
:rtype: `ImageSource`
"""
if not self.layers:
return BlankImageSource(size=size,
image_opts=image_opts,
cacheable=True)
if len(self.layers) == 1:
layer_img, layer_coverage = self.layers[0]
layer_opts = layer_img.image_opts
if (((layer_opts and not layer_opts.transparent)
or image_opts.transparent)
and (not size or size == layer_img.size)
and (not layer_coverage or not layer_coverage.clip)
and not coverage):
# layer is opaque, no need to make transparent or add bgcolor
return layer_img
if size is None:
size = self.layers[0][0].size
cacheable = self.cacheable
result = create_image(size, image_opts)
for layer_img, layer_coverage in self.layers:
if not layer_img.cacheable:
cacheable = False
img = layer_img.as_image()
layer_image_opts = layer_img.image_opts
if layer_image_opts is None:
opacity = None
else:
opacity = layer_image_opts.opacity
if layer_coverage and layer_coverage.clip:
img = mask_image(img, bbox, bbox_srs, layer_coverage)
if result.mode != 'RGBA':
merge_composite = False
else:
merge_composite = has_alpha_composite_support()
if 'transparency' in img.info:
# non-paletted PNGs can have a fixed transparency value
# convert to RGBA to have full alpha
img = img.convert('RGBA')
if merge_composite:
if opacity is not None and opacity < 1.0:
# fade-out img to add opacity value
img = img.convert("RGBA")
alpha = img.split()[3]
alpha = ImageChops.multiply(
alpha, ImageChops.constant(alpha, int(255 * opacity)))
img.putalpha(alpha)
if img.mode in ('RGBA', 'P'):
# assume paletted images have transparency
if img.mode == 'P':
img = img.convert('RGBA')
result = Image.alpha_composite(result, img)
else:
result.paste(img, (0, 0))
else:
if opacity is not None and opacity < 1.0:
img = img.convert(result.mode)
result = Image.blend(result, img, layer_image_opts.opacity)
elif img.mode in ('RGBA', 'P'):
# assume paletted images have transparency
if img.mode == 'P':
img = img.convert('RGBA')
# paste w transparency mask from layer
result.paste(img, (0, 0), img)
else:
result.paste(img, (0, 0))
# apply global clip coverage
if coverage:
bg = create_image(size, image_opts)
mask = mask_image(result, bbox, bbox_srs, coverage)
bg.paste(result, (0, 0), mask)
result = bg
return ImageSource(result,
size=size,
image_opts=image_opts,
cacheable=cacheable)