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author | S. Solomon Darnell | 2025-03-28 21:52:21 -0500 |
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committer | S. Solomon Darnell | 2025-03-28 21:52:21 -0500 |
commit | 4a52a71956a8d46fcb7294ac71734504bb09bcc2 (patch) | |
tree | ee3dc5af3b6313e921cd920906356f5d4febc4ed /.venv/lib/python3.12/site-packages/PIL/ImageStat.py | |
parent | cc961e04ba734dd72309fb548a2f97d67d578813 (diff) | |
download | gn-ai-master.tar.gz |
Diffstat (limited to '.venv/lib/python3.12/site-packages/PIL/ImageStat.py')
-rw-r--r-- | .venv/lib/python3.12/site-packages/PIL/ImageStat.py | 160 |
1 files changed, 160 insertions, 0 deletions
diff --git a/.venv/lib/python3.12/site-packages/PIL/ImageStat.py b/.venv/lib/python3.12/site-packages/PIL/ImageStat.py new file mode 100644 index 00000000..8bc50452 --- /dev/null +++ b/.venv/lib/python3.12/site-packages/PIL/ImageStat.py @@ -0,0 +1,160 @@ +# +# The Python Imaging Library. +# $Id$ +# +# global image statistics +# +# History: +# 1996-04-05 fl Created +# 1997-05-21 fl Added mask; added rms, var, stddev attributes +# 1997-08-05 fl Added median +# 1998-07-05 hk Fixed integer overflow error +# +# Notes: +# This class shows how to implement delayed evaluation of attributes. +# To get a certain value, simply access the corresponding attribute. +# The __getattr__ dispatcher takes care of the rest. +# +# Copyright (c) Secret Labs AB 1997. +# Copyright (c) Fredrik Lundh 1996-97. +# +# See the README file for information on usage and redistribution. +# +from __future__ import annotations + +import math +from functools import cached_property + +from . import Image + + +class Stat: + def __init__( + self, image_or_list: Image.Image | list[int], mask: Image.Image | None = None + ) -> None: + """ + Calculate statistics for the given image. If a mask is included, + only the regions covered by that mask are included in the + statistics. You can also pass in a previously calculated histogram. + + :param image: A PIL image, or a precalculated histogram. + + .. note:: + + For a PIL image, calculations rely on the + :py:meth:`~PIL.Image.Image.histogram` method. The pixel counts are + grouped into 256 bins, even if the image has more than 8 bits per + channel. So ``I`` and ``F`` mode images have a maximum ``mean``, + ``median`` and ``rms`` of 255, and cannot have an ``extrema`` maximum + of more than 255. + + :param mask: An optional mask. + """ + if isinstance(image_or_list, Image.Image): + self.h = image_or_list.histogram(mask) + elif isinstance(image_or_list, list): + self.h = image_or_list + else: + msg = "first argument must be image or list" # type: ignore[unreachable] + raise TypeError(msg) + self.bands = list(range(len(self.h) // 256)) + + @cached_property + def extrema(self) -> list[tuple[int, int]]: + """ + Min/max values for each band in the image. + + .. note:: + This relies on the :py:meth:`~PIL.Image.Image.histogram` method, and + simply returns the low and high bins used. This is correct for + images with 8 bits per channel, but fails for other modes such as + ``I`` or ``F``. Instead, use :py:meth:`~PIL.Image.Image.getextrema` to + return per-band extrema for the image. This is more correct and + efficient because, for non-8-bit modes, the histogram method uses + :py:meth:`~PIL.Image.Image.getextrema` to determine the bins used. + """ + + def minmax(histogram: list[int]) -> tuple[int, int]: + res_min, res_max = 255, 0 + for i in range(256): + if histogram[i]: + res_min = i + break + for i in range(255, -1, -1): + if histogram[i]: + res_max = i + break + return res_min, res_max + + return [minmax(self.h[i:]) for i in range(0, len(self.h), 256)] + + @cached_property + def count(self) -> list[int]: + """Total number of pixels for each band in the image.""" + return [sum(self.h[i : i + 256]) for i in range(0, len(self.h), 256)] + + @cached_property + def sum(self) -> list[float]: + """Sum of all pixels for each band in the image.""" + + v = [] + for i in range(0, len(self.h), 256): + layer_sum = 0.0 + for j in range(256): + layer_sum += j * self.h[i + j] + v.append(layer_sum) + return v + + @cached_property + def sum2(self) -> list[float]: + """Squared sum of all pixels for each band in the image.""" + + v = [] + for i in range(0, len(self.h), 256): + sum2 = 0.0 + for j in range(256): + sum2 += (j**2) * float(self.h[i + j]) + v.append(sum2) + return v + + @cached_property + def mean(self) -> list[float]: + """Average (arithmetic mean) pixel level for each band in the image.""" + return [self.sum[i] / self.count[i] for i in self.bands] + + @cached_property + def median(self) -> list[int]: + """Median pixel level for each band in the image.""" + + v = [] + for i in self.bands: + s = 0 + half = self.count[i] // 2 + b = i * 256 + for j in range(256): + s = s + self.h[b + j] + if s > half: + break + v.append(j) + return v + + @cached_property + def rms(self) -> list[float]: + """RMS (root-mean-square) for each band in the image.""" + return [math.sqrt(self.sum2[i] / self.count[i]) for i in self.bands] + + @cached_property + def var(self) -> list[float]: + """Variance for each band in the image.""" + return [ + (self.sum2[i] - (self.sum[i] ** 2.0) / self.count[i]) / self.count[i] + for i in self.bands + ] + + @cached_property + def stddev(self) -> list[float]: + """Standard deviation for each band in the image.""" + return [math.sqrt(self.var[i]) for i in self.bands] + + +Global = Stat # compatibility |