Source code for PIL.ImageEnhance

#
# The Python Imaging Library.
# $Id$
#
# image enhancement classes
#
# For a background, see "Image Processing By Interpolation and
# Extrapolation", Paul Haeberli and Douglas Voorhies.  Available
# at http://www.graficaobscura.com/interp/index.html
#
# History:
# 1996-03-23 fl  Created
# 2009-06-16 fl  Fixed mean calculation
#
# Copyright (c) Secret Labs AB 1997.
# Copyright (c) Fredrik Lundh 1996.
#
# See the README file for information on usage and redistribution.
#

from . import Image, ImageFilter, ImageStat


[docs]class _Enhance:
[docs] def enhance(self, factor): """ Returns an enhanced image. :param factor: A floating point value controlling the enhancement. Factor 1.0 always returns a copy of the original image, lower factors mean less color (brightness, contrast, etc), and higher values more. There are no restrictions on this value. :rtype: :py:class:`~PIL.Image.Image` """ return Image.blend(self.degenerate, self.image, factor)
[docs]class Color(_Enhance): """Adjust image color balance. This class can be used to adjust the colour balance of an image, in a manner similar to the controls on a colour TV set. An enhancement factor of 0.0 gives a black and white image. A factor of 1.0 gives the original image. """ def __init__(self, image): self.image = image self.intermediate_mode = "L" if "A" in image.getbands(): self.intermediate_mode = "LA" self.degenerate = image.convert(self.intermediate_mode).convert(image.mode)
[docs]class Contrast(_Enhance): """Adjust image contrast. This class can be used to control the contrast of an image, similar to the contrast control on a TV set. An enhancement factor of 0.0 gives a solid grey image. A factor of 1.0 gives the original image. """ def __init__(self, image): self.image = image mean = int(ImageStat.Stat(image.convert("L")).mean[0] + 0.5) self.degenerate = Image.new("L", image.size, mean).convert(image.mode) if "A" in image.getbands(): self.degenerate.putalpha(image.getchannel("A"))
[docs]class Brightness(_Enhance): """Adjust image brightness. This class can be used to control the brightness of an image. An enhancement factor of 0.0 gives a black image. A factor of 1.0 gives the original image. """ def __init__(self, image): self.image = image self.degenerate = Image.new(image.mode, image.size, 0) if "A" in image.getbands(): self.degenerate.putalpha(image.getchannel("A"))
[docs]class Sharpness(_Enhance): """Adjust image sharpness. This class can be used to adjust the sharpness of an image. An enhancement factor of 0.0 gives a blurred image, a factor of 1.0 gives the original image, and a factor of 2.0 gives a sharpened image. """ def __init__(self, image): self.image = image self.degenerate = image.filter(ImageFilter.SMOOTH) if "A" in image.getbands(): self.degenerate.putalpha(image.getchannel("A"))