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from pilkit.lib import Image, ImageColor, ImageEnhance
class ProcessorPipeline(list):
"""
A :class:`list` of other processors. This class allows any object that
knows how to deal with a single processor to deal with a list of them.
For example::
processed_image = ProcessorPipeline([ProcessorA(), ProcessorB()]).process(image)
"""
def process(self, img):
for proc in self:
img = proc.process(img)
return img
class Adjust(object):
"""
Performs color, brightness, contrast, and sharpness enhancements on the
image. See :mod:`PIL.ImageEnhance` for more imformation.
"""
def __init__(self, color=1.0, brightness=1.0, contrast=1.0, sharpness=1.0):
"""
:param color: A number between 0 and 1 that specifies the saturation
of the image. 0 corresponds to a completely desaturated image
(black and white) and 1 to the original color.
See :class:`PIL.ImageEnhance.Color`
:param brightness: A number representing the brightness; 0 results in
a completely black image whereas 1 corresponds to the brightness
of the original. See :class:`PIL.ImageEnhance.Brightness`
:param contrast: A number representing the contrast; 0 results in a
completely gray image whereas 1 corresponds to the contrast of
the original. See :class:`PIL.ImageEnhance.Contrast`
:param sharpness: A number representing the sharpness; 0 results in a
blurred image; 1 corresponds to the original sharpness; 2
results in a sharpened image. See
:class:`PIL.ImageEnhance.Sharpness`
"""
self.color = color
self.brightness = brightness
self.contrast = contrast
self.sharpness = sharpness
def process(self, img):
original = img = img.convert('RGBA')
for name in ['Color', 'Brightness', 'Contrast', 'Sharpness']:
factor = getattr(self, name.lower())
if factor != 1.0:
try:
img = getattr(ImageEnhance, name)(img).enhance(factor)
except ValueError:
pass
else:
# PIL's Color and Contrast filters both convert the image
# to L mode, losing transparency info, so we put it back.
# See https://github.com/jdriscoll/django-imagekit/issues/64
if name in ('Color', 'Contrast'):
img = Image.merge('RGBA', img.split()[:3] +
original.split()[3:4])
return img
class Reflection(object):
"""
Creates an image with a reflection.
"""
def __init__(self, background_color='#FFFFFF', size=0.0, opacity=0.6):
self.background_color = background_color
self.size = size
self.opacity = opacity
def process(self, img):
# Convert bgcolor string to RGB value.
background_color = ImageColor.getrgb(self.background_color)
# Handle palleted images.
img = img.convert('RGBA')
# Copy orignial image and flip the orientation.
reflection = img.copy().transpose(Image.FLIP_TOP_BOTTOM)
# Create a new image filled with the bgcolor the same size.
background = Image.new("RGBA", img.size, background_color)
# Calculate our alpha mask.
start = int(255 - (255 * self.opacity)) # The start of our gradient.
steps = int(255 * self.size) # The number of intermedite values.
increment = (255 - start) / float(steps)
mask = Image.new('L', (1, 255))
for y in range(255):
if y < steps:
val = int(y * increment + start)
else:
val = 255
mask.putpixel((0, y), val)
alpha_mask = mask.resize(img.size)
# Merge the reflection onto our background color using the alpha mask.
reflection = Image.composite(background, reflection, alpha_mask)
# Crop the reflection.
reflection_height = int(img.size[1] * self.size)
reflection = reflection.crop((0, 0, img.size[0], reflection_height))
# Create new image sized to hold both the original image and
# the reflection.
composite = Image.new("RGBA", (img.size[0], img.size[1] + reflection_height), background_color)
# Paste the orignal image and the reflection into the composite image.
composite.paste(img, (0, 0))
composite.paste(reflection, (0, img.size[1]))
# Return the image complete with reflection effect.
return composite
class Transpose(object):
"""
Rotates or flips the image.
"""
AUTO = 'auto'
FLIP_HORIZONTAL = Image.FLIP_LEFT_RIGHT
FLIP_VERTICAL = Image.FLIP_TOP_BOTTOM
ROTATE_90 = Image.ROTATE_90
ROTATE_180 = Image.ROTATE_180
ROTATE_270 = Image.ROTATE_270
methods = [AUTO]
_EXIF_ORIENTATION_STEPS = {
1: [],
2: [FLIP_HORIZONTAL],
3: [ROTATE_180],
4: [FLIP_VERTICAL],
5: [ROTATE_270, FLIP_HORIZONTAL],
6: [ROTATE_270],
7: [ROTATE_90, FLIP_HORIZONTAL],
8: [ROTATE_90],
}
def __init__(self, *args):
"""
Possible arguments:
- Transpose.AUTO
- Transpose.FLIP_HORIZONTAL
- Transpose.FLIP_VERTICAL
- Transpose.ROTATE_90
- Transpose.ROTATE_180
- Transpose.ROTATE_270
The order of the arguments dictates the order in which the
Transposition steps are taken.
If Transpose.AUTO is present, all other arguments are ignored, and
the processor will attempt to rotate the image according to the
EXIF Orientation data.
"""
super(Transpose, self).__init__()
if args:
self.methods = args
def process(self, img):
if self.AUTO in self.methods:
try:
orientation = img._getexif()[0x0112]
ops = self._EXIF_ORIENTATION_STEPS[orientation]
except (IndexError, KeyError, TypeError, AttributeError):
ops = []
else:
ops = self.methods
for method in ops:
img = img.transpose(method)
return img
class Anchor(object):
"""
Defines all the anchor points needed by the various processor classes.
"""
TOP_LEFT = 'tl'
TOP = 't'
TOP_RIGHT = 'tr'
BOTTOM_LEFT = 'bl'
BOTTOM = 'b'
BOTTOM_RIGHT = 'br'
CENTER = 'c'
LEFT = 'l'
RIGHT = 'r'
_ANCHOR_PTS = {
TOP_LEFT: (0, 0),
TOP: (0.5, 0),
TOP_RIGHT: (1, 0),
LEFT: (0, 0.5),
CENTER: (0.5, 0.5),
RIGHT: (1, 0.5),
BOTTOM_LEFT: (0, 1),
BOTTOM: (0.5, 1),
BOTTOM_RIGHT: (1, 1),
}
@staticmethod
def get_tuple(anchor):
"""Normalizes anchor values (strings or tuples) to tuples.
"""
# If the user passed in one of the string values, convert it to a
# percentage tuple.
if anchor in Anchor._ANCHOR_PTS.keys():
anchor = Anchor._ANCHOR_PTS[anchor]
return anchor
class MakeOpaque(object):
"""
Pastes the provided image onto an image of a solid color. Used for when you
want to make transparent images opaque.
"""
def __init__(self, background_color=(255, 255, 255)):
self.background_color = background_color
def process(self, img):
img = img.convert('RGBA')
new_img = Image.new('RGBA', img.size, self.background_color)
new_img.paste(img, img)
return new_img