Files
mayan-edms/mayan/apps/converter/transformations.py
Roberto Rosario 42a7ebeea2 Finish redactions app
Signed-off-by: Roberto Rosario <roberto.rosario@mayan-edms.com>
2019-06-26 14:16:11 -04:00

540 lines
15 KiB
Python

from __future__ import unicode_literals
import hashlib
import logging
from PIL import Image, ImageColor, ImageDraw, ImageFilter
from django.utils.translation import string_concat, ugettext_lazy as _
from django.utils.encoding import force_bytes
logger = logging.getLogger(__name__)
class BaseTransformation(object):
"""
Transformation can modify the appearance of the document's page preview.
Some transformation available are: Rotate, zoom, resize and crop.
"""
arguments = ()
name = 'base_transformation'
_registry = {}
@staticmethod
def combine(transformations):
result = None
for transformation in transformations:
if not result:
result = hashlib.sha256(transformation.cache_hash())
else:
result.update(transformation.cache_hash())
return result.hexdigest()
@classmethod
def get(cls, name):
return cls._registry[name]
@classmethod
def get_label(cls):
if cls.arguments:
return string_concat(cls.label, ': ', ', '.join(cls.arguments))
else:
return cls.label
@classmethod
def get_transformation_choices(cls):
return sorted(
[
(name, klass.get_label()) for name, klass in cls._registry.items()
]
)
@classmethod
def register(cls, transformation):
cls._registry[transformation.name] = transformation
def __init__(self, **kwargs):
self.kwargs = {}
for argument_name in self.arguments:
setattr(self, argument_name, kwargs.get(argument_name))
self.kwargs[argument_name] = kwargs.get(argument_name)
def cache_hash(self):
result = hashlib.sha256(force_bytes(self.name))
# Sort arguments for guaranteed repeatability
for key, value in sorted(self.kwargs.items()):
result.update(force_bytes(key))
result.update(force_bytes(value))
return force_bytes(result.hexdigest())
def execute_on(self, image):
self.image = image
self.aspect = 1.0 * image.size[0] / image.size[1]
class TransformationCrop(BaseTransformation):
arguments = ('left', 'top', 'right', 'bottom',)
label = _('Crop')
name = 'crop'
def execute_on(self, *args, **kwargs):
super(TransformationCrop, self).execute_on(*args, **kwargs)
try:
left = int(self.left or '0')
except ValueError:
left = 0
try:
top = int(self.top or '0')
except ValueError:
top = 0
try:
right = int(self.right or '0')
except ValueError:
right = 0
try:
bottom = int(self.bottom or '0')
except ValueError:
bottom = 0
if left < 0:
left = 0
if left > self.image.size[0] - 1:
left = self.image.size[0] - 1
if top < 0:
top = 0
if top > self.image.size[1] - 1:
top = self.image.size[1] - 1
if right < 0:
right = 0
if right > self.image.size[0] - 1:
right = self.image.size[0] - 1
if bottom < 0:
bottom = 0
if bottom > self.image.size[1] - 1:
bottom = self.image.size[1] - 1
# Invert right value
# Pillow uses left, top, right, bottom to define a viewport
# of real coordinates
# We invert the right and bottom to define a viewport
# that can crop from the right and bottom borders without
# having to know the real dimensions of an image
right = self.image.size[0] - right
bottom = self.image.size[1] - bottom
if left > right:
left = right - 1
if top > bottom:
top = bottom - 1
logger.debug(
'left: %f, top: %f, right: %f, bottom: %f', left, top, right,
bottom
)
return self.image.crop((left, top, right, bottom))
class TransformationDrawRectangle(BaseTransformation):
arguments = (
'left', 'top', 'right', 'bottom', 'fillcolor', 'outlinecolor',
'outlinewidth'
)
label = _('Draw rectangle')
name = 'draw_rectangle'
def execute_on(self, *args, **kwargs):
super(TransformationDrawRectangle, self).execute_on(*args, **kwargs)
try:
left = int(self.left or '0')
except ValueError:
left = 0
try:
top = int(self.top or '0')
except ValueError:
top = 0
try:
right = int(self.right or '0')
except ValueError:
right = 0
try:
bottom = int(self.bottom or '0')
except ValueError:
bottom = 0
if left < 0:
left = 0
if left > self.image.size[0] - 1:
left = self.image.size[0] - 1
if top < 0:
top = 0
if top > self.image.size[1] - 1:
top = self.image.size[1] - 1
if right < 0:
right = 0
if right > self.image.size[0] - 1:
right = self.image.size[0] - 1
if bottom < 0:
bottom = 0
if bottom > self.image.size[1] - 1:
bottom = self.image.size[1] - 1
# Invert right value
# Pillow uses left, top, right, bottom to define a viewport
# of real coordinates
# We invert the right and bottom to define a viewport
# that can crop from the right and bottom borders without
# having to know the real dimensions of an image
right = self.image.size[0] - right
bottom = self.image.size[1] - bottom
if left > right:
left = right - 1
if top > bottom:
top = bottom - 1
logger.debug(
'left: %f, top: %f, right: %f, bottom: %f', left, top, right,
bottom
)
fillcolor_value = getattr(self, 'fillcolor', None)
if fillcolor_value:
fill_color = ImageColor.getrgb(fillcolor_value)
else:
fill_color = 0
outlinecolor_value = getattr(self, 'outlinecolor', None)
if outlinecolor_value:
outline_color = ImageColor.getrgb(outlinecolor_value)
else:
outline_color = None
outlinewidth_value = getattr(self, 'outlinewidth', None)
if outlinewidth_value:
outline_width = int(outlinewidth_value)
else:
outline_width = 0
draw = ImageDraw.Draw(self.image)
draw.rectangle(
(left, top, right, bottom), fill=fill_color, outline=outline_color,
width=outline_width
)
return self.image
class TransformationDrawRectanglePercent(BaseTransformation):
arguments = (
'left', 'top', 'right', 'bottom', 'fillcolor', 'outlinecolor',
'outlinewidth'
)
label = _('Draw rectangle (percents coordinates)')
name = 'draw_rectangle_percent'
def execute_on(self, *args, **kwargs):
super(TransformationDrawRectanglePercent, self).execute_on(*args, **kwargs)
try:
left = float(self.left or '0')
except ValueError:
left = 0
try:
top = float(self.top or '0')
except ValueError:
top = 0
try:
right = float(self.right or '0')
except ValueError:
right = 0
try:
bottom = float(self.bottom or '0')
except ValueError:
bottom = 0
if left < 0:
left = 0
if left > 100:
left = 100
if top < 0:
top = 0
if top > 100:
top = 100
if right < 0:
right = 0
if right > 100:
right = 100
if bottom < 0:
bottom = 0
if bottom > 100:
bottom = 100
#if left > right:
# left, right = right, left
#if top > bottom:
# top, bottom = bottom, top
logger.debug(
'left: %f, top: %f, right: %f, bottom: %f', left, top, right,
bottom
)
fillcolor_value = getattr(self, 'fillcolor', None)
if fillcolor_value:
fill_color = ImageColor.getrgb(fillcolor_value)
else:
fill_color = 0
outlinecolor_value = getattr(self, 'outlinecolor', None)
if outlinecolor_value:
outline_color = ImageColor.getrgb(outlinecolor_value)
else:
outline_color = None
outlinewidth_value = getattr(self, 'outlinewidth', None)
if outlinewidth_value:
outline_width = int(outlinewidth_value)
else:
outline_width = 0
left = left / 100.0 * self.image.size[0]
top = top / 100.0 * self.image.size[1]
# Invert right value
# Pillow uses left, top, right, bottom to define a viewport
# of real coordinates
# We invert the right and bottom to define a viewport
# that can crop from the right and bottom borders without
# having to know the real dimensions of an image
right = self.image.size[0] - (right / 100.0 * self.image.size[0])
bottom = self.image.size[1] - (bottom / 100.0 * self.image.size[1])
draw = ImageDraw.Draw(self.image)
draw.rectangle(
(left, top, right, bottom), fill=fill_color, outline=outline_color,
width=outline_width
)
return self.image
class TransformationFlip(BaseTransformation):
arguments = ()
label = _('Flip')
name = 'flip'
def execute_on(self, *args, **kwargs):
super(TransformationFlip, self).execute_on(*args, **kwargs)
return self.image.transpose(Image.FLIP_TOP_BOTTOM)
class TransformationGaussianBlur(BaseTransformation):
arguments = ('radius',)
label = _('Gaussian blur')
name = 'gaussianblur'
def execute_on(self, *args, **kwargs):
super(TransformationGaussianBlur, self).execute_on(*args, **kwargs)
return self.image.filter(ImageFilter.GaussianBlur(radius=self.radius))
class TransformationLineArt(BaseTransformation):
label = _('Line art')
name = 'lineart'
def execute_on(self, *args, **kwargs):
super(TransformationLineArt, self).execute_on(*args, **kwargs)
return self.image.convert('L').point(lambda x: 0 if x < 128 else 255, '1')
class TransformationMirror(BaseTransformation):
arguments = ()
label = _('Mirror')
name = 'mirror'
def execute_on(self, *args, **kwargs):
super(TransformationMirror, self).execute_on(*args, **kwargs)
return self.image.transpose(Image.FLIP_LEFT_RIGHT)
class TransformationResize(BaseTransformation):
arguments = ('width', 'height')
label = _('Resize')
name = 'resize'
def execute_on(self, *args, **kwargs):
super(TransformationResize, self).execute_on(*args, **kwargs)
width = int(self.width)
height = int(self.height or 1.0 * width / self.aspect)
factor = 1
while self.image.size[0] / factor > 2 * width and self.image.size[1] * 2 / factor > 2 * height:
factor *= 2
if factor > 1:
self.image.thumbnail(
(self.image.size[0] / factor, self.image.size[1] / factor),
Image.NEAREST
)
# Resize the image with best quality algorithm ANTI-ALIAS
self.image.thumbnail((width, height), Image.ANTIALIAS)
return self.image
class TransformationRotate(BaseTransformation):
arguments = ('degrees', 'fillcolor')
label = _('Rotate')
name = 'rotate'
def execute_on(self, *args, **kwargs):
super(TransformationRotate, self).execute_on(*args, **kwargs)
self.degrees %= 360
if self.degrees == 0:
return self.image
fillcolor_value = getattr(self, 'fillcolor', None)
if fillcolor_value:
fillcolor = ImageColor.getrgb(fillcolor_value)
else:
fillcolor = None
return self.image.rotate(
angle=360 - self.degrees, resample=Image.BICUBIC, expand=True,
fillcolor=fillcolor
)
class TransformationRotate90(TransformationRotate):
arguments = ()
degrees = 90
label = _('Rotate 90 degrees')
name = 'rotate90'
def __init__(self, **kwargs):
super(TransformationRotate90, self).__init__()
self.kwargs['degrees'] = 90
class TransformationRotate180(TransformationRotate):
arguments = ()
degrees = 180
label = _('Rotate 180 degrees')
name = 'rotate180'
def __init__(self, **kwargs):
super(TransformationRotate180, self).__init__()
self.kwargs['degrees'] = 180
class TransformationRotate270(TransformationRotate):
arguments = ()
degrees = 270
label = _('Rotate 270 degrees')
name = 'rotate270'
def __init__(self, **kwargs):
super(TransformationRotate270, self).__init__()
self.kwargs['degrees'] = 270
class TransformationUnsharpMask(BaseTransformation):
arguments = ('radius', 'percent', 'threshold')
label = _('Unsharp masking')
name = 'unsharpmask'
def execute_on(self, *args, **kwargs):
super(TransformationUnsharpMask, self).execute_on(*args, **kwargs)
return self.image.filter(
ImageFilter.UnsharpMask(
radius=self.radius, percent=self.percent,
threshold=self.threshold
)
)
class TransformationZoom(BaseTransformation):
arguments = ('percent',)
label = _('Zoom')
name = 'zoom'
def execute_on(self, *args, **kwargs):
super(TransformationZoom, self).execute_on(*args, **kwargs)
if self.percent == 100:
return self.image
decimal_value = float(self.percent) / 100
return self.image.resize(
(
int(self.image.size[0] * decimal_value),
int(self.image.size[1] * decimal_value)
), Image.ANTIALIAS
)
BaseTransformation.register(transformation=TransformationCrop)
BaseTransformation.register(transformation=TransformationDrawRectangle)
BaseTransformation.register(transformation=TransformationDrawRectanglePercent)
BaseTransformation.register(transformation=TransformationFlip)
BaseTransformation.register(transformation=TransformationGaussianBlur)
BaseTransformation.register(transformation=TransformationLineArt)
BaseTransformation.register(transformation=TransformationMirror)
BaseTransformation.register(transformation=TransformationResize)
BaseTransformation.register(transformation=TransformationRotate)
BaseTransformation.register(transformation=TransformationRotate90)
BaseTransformation.register(transformation=TransformationRotate180)
BaseTransformation.register(transformation=TransformationRotate270)
BaseTransformation.register(transformation=TransformationUnsharpMask)
BaseTransformation.register(transformation=TransformationZoom)