## The Python Imaging Library.# $Id$## standard channel operations## History:# 1996-03-24 fl Created# 1996-08-13 fl Added logical operations (for "1" images)# 2000-10-12 fl Added offset method (from Image.py)## Copyright (c) 1997-2000 by Secret Labs AB# Copyright (c) 1996-2000 by Fredrik Lundh## See the README file for information on usage and redistribution.#from.importImage
[docs]defconstant(image,value):"""Fill a channel with a given grey level. :rtype: :py:class:`~PIL.Image.Image` """returnImage.new("L",image.size,value)
[docs]defduplicate(image):"""Copy a channel. Alias for :py:meth:`PIL.Image.Image.copy`. :rtype: :py:class:`~PIL.Image.Image` """returnimage.copy()
[docs]definvert(image):""" Invert an image (channel). .. code-block:: python out = MAX - image :rtype: :py:class:`~PIL.Image.Image` """image.load()returnimage._new(image.im.chop_invert())
[docs]deflighter(image1,image2):""" Compares the two images, pixel by pixel, and returns a new image containing the lighter values. .. code-block:: python out = max(image1, image2) :rtype: :py:class:`~PIL.Image.Image` """image1.load()image2.load()returnimage1._new(image1.im.chop_lighter(image2.im))
[docs]defdarker(image1,image2):""" Compares the two images, pixel by pixel, and returns a new image containing the darker values. .. code-block:: python out = min(image1, image2) :rtype: :py:class:`~PIL.Image.Image` """image1.load()image2.load()returnimage1._new(image1.im.chop_darker(image2.im))
[docs]defdifference(image1,image2):""" Returns the absolute value of the pixel-by-pixel difference between the two images. .. code-block:: python out = abs(image1 - image2) :rtype: :py:class:`~PIL.Image.Image` """image1.load()image2.load()returnimage1._new(image1.im.chop_difference(image2.im))
[docs]defmultiply(image1,image2):""" Superimposes two images on top of each other. If you multiply an image with a solid black image, the result is black. If you multiply with a solid white image, the image is unaffected. .. code-block:: python out = image1 * image2 / MAX :rtype: :py:class:`~PIL.Image.Image` """image1.load()image2.load()returnimage1._new(image1.im.chop_multiply(image2.im))
[docs]defscreen(image1,image2):""" Superimposes two inverted images on top of each other. .. code-block:: python out = MAX - ((MAX - image1) * (MAX - image2) / MAX) :rtype: :py:class:`~PIL.Image.Image` """image1.load()image2.load()returnimage1._new(image1.im.chop_screen(image2.im))
[docs]defsoft_light(image1,image2):""" Superimposes two images on top of each other using the Soft Light algorithm :rtype: :py:class:`~PIL.Image.Image` """image1.load()image2.load()returnimage1._new(image1.im.chop_soft_light(image2.im))
[docs]defhard_light(image1,image2):""" Superimposes two images on top of each other using the Hard Light algorithm :rtype: :py:class:`~PIL.Image.Image` """image1.load()image2.load()returnimage1._new(image1.im.chop_hard_light(image2.im))
[docs]defoverlay(image1,image2):""" Superimposes two images on top of each other using the Overlay algorithm :rtype: :py:class:`~PIL.Image.Image` """image1.load()image2.load()returnimage1._new(image1.im.chop_overlay(image2.im))
[docs]defadd(image1,image2,scale=1.0,offset=0):""" Adds two images, dividing the result by scale and adding the offset. If omitted, scale defaults to 1.0, and offset to 0.0. .. code-block:: python out = ((image1 + image2) / scale + offset) :rtype: :py:class:`~PIL.Image.Image` """image1.load()image2.load()returnimage1._new(image1.im.chop_add(image2.im,scale,offset))
[docs]defsubtract(image1,image2,scale=1.0,offset=0):""" Subtracts two images, dividing the result by scale and adding the offset. If omitted, scale defaults to 1.0, and offset to 0.0. .. code-block:: python out = ((image1 - image2) / scale + offset) :rtype: :py:class:`~PIL.Image.Image` """image1.load()image2.load()returnimage1._new(image1.im.chop_subtract(image2.im,scale,offset))
[docs]defadd_modulo(image1,image2):"""Add two images, without clipping the result. .. code-block:: python out = ((image1 + image2) % MAX) :rtype: :py:class:`~PIL.Image.Image` """image1.load()image2.load()returnimage1._new(image1.im.chop_add_modulo(image2.im))
[docs]defsubtract_modulo(image1,image2):"""Subtract two images, without clipping the result. .. code-block:: python out = ((image1 - image2) % MAX) :rtype: :py:class:`~PIL.Image.Image` """image1.load()image2.load()returnimage1._new(image1.im.chop_subtract_modulo(image2.im))
[docs]deflogical_and(image1,image2):"""Logical AND between two images. Both of the images must have mode "1". If you would like to perform a logical AND on an image with a mode other than "1", try :py:meth:`~PIL.ImageChops.multiply` instead, using a black-and-white mask as the second image. .. code-block:: python out = ((image1 and image2) % MAX) :rtype: :py:class:`~PIL.Image.Image` """image1.load()image2.load()returnimage1._new(image1.im.chop_and(image2.im))
[docs]deflogical_or(image1,image2):"""Logical OR between two images. Both of the images must have mode "1". .. code-block:: python out = ((image1 or image2) % MAX) :rtype: :py:class:`~PIL.Image.Image` """image1.load()image2.load()returnimage1._new(image1.im.chop_or(image2.im))
[docs]deflogical_xor(image1,image2):"""Logical XOR between two images. Both of the images must have mode "1". .. code-block:: python out = ((bool(image1) != bool(image2)) % MAX) :rtype: :py:class:`~PIL.Image.Image` """image1.load()image2.load()returnimage1._new(image1.im.chop_xor(image2.im))
[docs]defblend(image1,image2,alpha):"""Blend images using constant transparency weight. Alias for :py:func:`PIL.Image.blend`. :rtype: :py:class:`~PIL.Image.Image` """returnImage.blend(image1,image2,alpha)
[docs]defcomposite(image1,image2,mask):"""Create composite using transparency mask. Alias for :py:func:`PIL.Image.composite`. :rtype: :py:class:`~PIL.Image.Image` """returnImage.composite(image1,image2,mask)
[docs]defoffset(image,xoffset,yoffset=None):"""Returns a copy of the image where data has been offset by the given distances. Data wraps around the edges. If ``yoffset`` is omitted, it is assumed to be equal to ``xoffset``. :param image: Input image. :param xoffset: The horizontal distance. :param yoffset: The vertical distance. If omitted, both distances are set to the same value. :rtype: :py:class:`~PIL.Image.Image` """ifyoffsetisNone:yoffset=xoffsetimage.load()returnimage._new(image.im.offset(xoffset,yoffset))