codekingpro/portable-devtools

1#
2# The Python Imaging Library.
3# $Id$
4#
5# image enhancement classes
6#
7# For a background, see "Image Processing By Interpolation and
8# Extrapolation", Paul Haeberli and Douglas Voorhies.  Available
9# at http://www.graficaobscura.com/interp/index.html
10#
11# History:
12# 1996-03-23 fl  Created
13# 2009-06-16 fl  Fixed mean calculation
14#
15# Copyright (c) Secret Labs AB 1997.
16# Copyright (c) Fredrik Lundh 1996.
17#
18# See the README file for information on usage and redistribution.
19#
20from __future__ import annotations
21
22from . import Image, ImageFilter, ImageStat
23
24
25class _Enhance:
26    image: Image.Image
27    degenerate: Image.Image
28
29    def enhance(self, factor: float) -> Image.Image:
30        """
31        Returns an enhanced image.
32
33        :param factor: A floating point value controlling the enhancement.
34                       Factor 1.0 always returns a copy of the original image,
35                       lower factors mean less color (brightness, contrast,
36                       etc), and higher values more. There are no restrictions
37                       on this value.
38        :rtype: :py:class:`~PIL.Image.Image`
39        """
40        return Image.blend(self.degenerate, self.image, factor)
41
42
43class Color(_Enhance):
44    """Adjust image color balance.
45
46    This class can be used to adjust the colour balance of an image, in
47    a manner similar to the controls on a colour TV set. An enhancement
48    factor of 0.0 gives a black and white image. A factor of 1.0 gives
49    the original image.
50    """
51
52    def __init__(self, image: Image.Image) -> None:
53        self.image = image
54        self.intermediate_mode = "L"
55        if "A" in image.getbands():
56            self.intermediate_mode = "LA"
57
58        if self.intermediate_mode != image.mode:
59            image = image.convert(self.intermediate_mode).convert(image.mode)
60        self.degenerate = image
61
62
63class Contrast(_Enhance):
64    """Adjust image contrast.
65
66    This class can be used to control the contrast of an image, similar
67    to the contrast control on a TV set. An enhancement factor of 0.0
68    gives a solid gray image. A factor of 1.0 gives the original image.
69    """
70
71    def __init__(self, image: Image.Image) -> None:
72        self.image = image
73        if image.mode != "L":
74            image = image.convert("L")
75        mean = int(ImageStat.Stat(image).mean[0] + 0.5)
76        self.degenerate = Image.new("L", image.size, mean)
77        if self.degenerate.mode != self.image.mode:
78            self.degenerate = self.degenerate.convert(self.image.mode)
79
80        if "A" in self.image.getbands():
81            self.degenerate.putalpha(self.image.getchannel("A"))
82
83
84class Brightness(_Enhance):
85    """Adjust image brightness.
86
87    This class can be used to control the brightness of an image.  An
88    enhancement factor of 0.0 gives a black image. A factor of 1.0 gives the
89    original image.
90    """
91
92    def __init__(self, image: Image.Image) -> None:
93        self.image = image
94        self.degenerate = Image.new(image.mode, image.size, 0)
95
96        if "A" in image.getbands():
97            self.degenerate.putalpha(image.getchannel("A"))
98
99
100class Sharpness(_Enhance):
101    """Adjust image sharpness.
102
103    This class can be used to adjust the sharpness of an image. An
104    enhancement factor of 0.0 gives a blurred image, a factor of 1.0 gives the
105    original image, and a factor of 2.0 gives a sharpened image.
106    """
107
108    def __init__(self, image: Image.Image) -> None:
109        self.image = image
110        self.degenerate = image.filter(ImageFilter.SMOOTH)
111
112        if "A" in image.getbands():
113            self.degenerate.putalpha(image.getchannel("A"))
114