114 lines
3.5 KiB
Python
114 lines
3.5 KiB
Python
#
|
|
# 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 __future__ import annotations
|
|
|
|
from . import Image, ImageFilter, ImageStat
|
|
|
|
|
|
class _Enhance:
|
|
image: Image.Image
|
|
degenerate: Image.Image
|
|
|
|
def enhance(self, factor: float) -> Image.Image:
|
|
"""
|
|
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)
|
|
|
|
|
|
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: Image.Image) -> None:
|
|
self.image = image
|
|
self.intermediate_mode = "L"
|
|
if "A" in image.getbands():
|
|
self.intermediate_mode = "LA"
|
|
|
|
if self.intermediate_mode != image.mode:
|
|
image = image.convert(self.intermediate_mode).convert(image.mode)
|
|
self.degenerate = image
|
|
|
|
|
|
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 gray image. A factor of 1.0 gives the original image.
|
|
"""
|
|
|
|
def __init__(self, image: Image.Image) -> None:
|
|
self.image = image
|
|
if image.mode != "L":
|
|
image = image.convert("L")
|
|
mean = int(ImageStat.Stat(image).mean[0] + 0.5)
|
|
self.degenerate = Image.new("L", image.size, mean)
|
|
if self.degenerate.mode != self.image.mode:
|
|
self.degenerate = self.degenerate.convert(self.image.mode)
|
|
|
|
if "A" in self.image.getbands():
|
|
self.degenerate.putalpha(self.image.getchannel("A"))
|
|
|
|
|
|
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: Image.Image) -> None:
|
|
self.image = image
|
|
self.degenerate = Image.new(image.mode, image.size, 0)
|
|
|
|
if "A" in image.getbands():
|
|
self.degenerate.putalpha(image.getchannel("A"))
|
|
|
|
|
|
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: Image.Image) -> None:
|
|
self.image = image
|
|
self.degenerate = image.filter(ImageFilter.SMOOTH)
|
|
|
|
if "A" in image.getbands():
|
|
self.degenerate.putalpha(image.getchannel("A"))
|