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Diffstat (limited to 'PIL/ImageStat.py')
| -rw-r--r-- | PIL/ImageStat.py | 179 |
1 files changed, 0 insertions, 179 deletions
diff --git a/PIL/ImageStat.py b/PIL/ImageStat.py deleted file mode 100644 index d53e645..0000000 --- a/PIL/ImageStat.py +++ /dev/null @@ -1,179 +0,0 @@ -# -# The Python Imaging Library. -# $Id: ImageStat.py 2134 2004-10-06 08:55:20Z fredrik $ -# -# 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. -# - -import Image -import operator, math - -## -# The <b>ImageStat</b> module calculates global statistics for an -# image, or a region of an image. -## - -## -# Calculate statistics for the given image. If a mask is included, -# only the regions covered by that mask are included in the -# statistics. - -class Stat: - "Get image or feature statistics" - - ## - # Create a statistics object. - # - # @def __init__(image, mask=None) - # @param image A PIL image, or a precalculate histogram. - # @param mask An optional mask. - - def __init__(self, image_or_list, mask = None): - try: - if mask: - self.h = image_or_list.histogram(mask) - else: - self.h = image_or_list.histogram() - except AttributeError: - self.h = image_or_list # assume it to be a histogram list - if type(self.h) != type([]): - raise TypeError, "first argument must be image or list" - self.bands = range(len(self.h) / 256) - - def __getattr__(self, id): - "Calculate missing attribute" - if id[:4] == "_get": - raise AttributeError, id - # calculate missing attribute - v = getattr(self, "_get" + id)() - setattr(self, id, v) - return v - - def _getextrema(self): - "Get min/max values for each band in the image" - - def minmax(histogram): - n = 255 - x = 0 - for i in range(256): - if histogram[i]: - n = min(n, i) - x = max(x, i) - return n, x # returns (255, 0) if there's no data in the histogram - - v = [] - for i in range(0, len(self.h), 256): - v.append(minmax(self.h[i:])) - return v - - def _getcount(self): - "Get total number of pixels in each layer" - - v = [] - for i in range(0, len(self.h), 256): - v.append(reduce(operator.add, self.h[i:i+256])) - return v - - def _getsum(self): - "Get sum of all pixels in each layer" - - v = [] - for i in range(0, len(self.h), 256): - sum = 0.0 - for j in range(256): - sum = sum + j * self.h[i+j] - v.append(sum) - return v - - def _getsum2(self): - "Get squared sum of all pixels in each layer" - - v = [] - for i in range(0, len(self.h), 256): - sum2 = 0.0 - for j in range(256): - sum2 = sum2 + (j ** 2) * float(self.h[i+j]) - v.append(sum2) - return v - - def _getmean(self): - "Get average pixel level for each layer" - - v = [] - for i in self.bands: - v.append(self.sum[i] / self.count[i]) - return v - - def _getmedian(self): - "Get median pixel level for each layer" - - v = [] - for i in self.bands: - s = 0 - l = self.count[i]/2 - b = i * 256 - for j in range(256): - s = s + self.h[b+j] - if s > l: - break - v.append(j) - return v - - def _getrms(self): - "Get RMS for each layer" - - v = [] - for i in self.bands: - v.append(math.sqrt(self.sum2[i] / self.count[i])) - return v - - - def _getvar(self): - "Get variance for each layer" - - v = [] - for i in self.bands: - n = self.count[i] - v.append((self.sum2[i]-(self.sum[i]**2.0)/n)/n) - return v - - def _getstddev(self): - "Get standard deviation for each layer" - - v = [] - for i in self.bands: - v.append(math.sqrt(self.var[i])) - return v - -Global = Stat # compatibility - -if __name__ == "__main__": - - im = Image.open("Images/lena.ppm") - - st = Stat(im) - - print "extrema", st.extrema - print "sum ", st.sum - print "mean ", st.mean - print "median ", st.median - print "rms ", st.rms - print "sum2 ", st.sum2 - print "var ", st.var - print "stddev ", st.stddev |