filters.py

   1 from PIL import Image, ImageFilter
   2
   3 def edge_detection(image):
   4     image = image.filter(ImageFilter.GaussianBlur())
   5     # GaussianBlur is undocumented class, it might not work in future versions
   6     # of PIL
   7     image_l = image.load()
   8     new_image = Image.new('L', image.size)
   9     new_image_l = new_image.load()
  10
  11     for x in xrange(2, image.size[0] - 2):
  12         for y in xrange(2, image.size[1] - 2):
  13             pix = (sum([sum([
  14                 image_l[a, b]
  15                     for b in range(y - 2, y + 3)])
  16                     for a in range(x - 2, x + 3)])
  17                 - (25  * image_l[x, y]))
  18             if pix > 255:
  19                 pix = 255
  20             if pix < 0:
  21                 pix = 0
  22             new_image_l[x, y] = pix
  23     return new_image
  24
  25 def peaks(image):
  26     image_l = image.load()
  27     new_image = Image.new('L', image.size)
  28     new_image_l = new_image.load()
  29
  30     for x in range(2, image.size[0] - 2):
  31         for y in range(2, image.size[1] - 2):
  32             pix = (sum([sum([
  33                 - image_l[a, b]
  34                     for b in range(y - 2, y + 3)])
  35                     for a in range(x - 2, x + 3)])
  36                 + (16 * image_l[x, y]))
  37             if pix > 255:
  38                 pix = 255
  39             if pix < 0:
  40                 pix = 0
  41             new_image_l[x, y] = pix
  42     return new_image
  43
  44 def high_pass(image, height):
  45     image_l = image.load()
  46     new_image = Image.new('L', image.size)
  47     new_image_l = new_image.load()
  48
  49     for x in xrange(image.size[0]):
  50         for y in xrange(image.size[1]):
  51             if image_l[x, y] < height:
  52                 new_image_l[x, y] = 0
  53             else:
  54                 new_image_l[x, y] = image_l[x, y]
  55
  56     return new_image
  57
  58 def components(image):
  59     image_l = image.load()
  60     new_image = Image.new('L', image.size)
  61     new_image_l = new_image.load()
  62
  63     components = [None]
  64     comp_counter = 1
  65
  66     for y in xrange(1, image.size[1] - 1):
  67         for x in xrange(1, image.size[0] - 1):
  68             if image_l[x, y]:
  69                 s = {0}
  70                 s.add(new_image_l[x - 1, y - 1])
  71                 s.add(new_image_l[x, y - 1])
  72                 s.add(new_image_l[x + 1, y - 1])
  73                 s.add(new_image_l[x - 1, y])
  74                 if len(s) == 1:
  75                     components.append(set())
  76                     new_image_l[x, y] = comp_counter
  77                     components[comp_counter].add((x, y))
  78                     comp_counter += 1
  79                 elif len(s) == 2:
  80                     s.remove(0)
  81                     c = s.pop()
  82                     new_image_l[x, y] = c
  83                     components[c].add((x,y))
  84                 else:
  85                     s.remove(0)
  86                     c1, c2 = s.pop(), s.pop()
  87                     components[c2].add((x, y))
  88                     for (x1, y1) in components[c2]:
  89                         new_image_l[x1, y1] = c1
  90                     components[c1] = components[c1] | components[c2]
  91                     components[c2] = None
  92
  93     new_image = Image.new('L', image.size)
  94     new_image_l = new_image.load()
  95
  96     for component in components:
  97         if component:
  98             x_c = 0
  99             y_c = 0
 100             c = 0
 101             for (x, y) in component:
 102                 x_c += x
 103                 y_c += y
 104                 c += 1
 105             new_image_l[int(round(float(x_c)/c)), int(round(float(y_c)/c))] = 255
 106
 107
 108     return new_image
 109
 110 def components2(image):
 111     image_l = image.load()
 112     new_image = Image.new('L', image.size)
 113     new_image_l = new_image.load()
 114
 115     components = [None]
 116     comp_counter = 1
 117
 118     for y in xrange(2, image.size[1] - 2):
 119         for x in xrange(2, image.size[0] - 2):
 120             if image_l[x, y]:
 121
 122                 s = {0}
 123                 for (a, b) in [(a,b) for a in range(x - 2, x + 3)
 124                           for b in range(y - 2, y + 1)]:
 125                     if not (b == y and a >= x):
 126                         s.add(new_image_l[a, b])
 127
 128                 if len(s) == 1:
 129                     components.append(set())
 130                     new_image_l[x, y] = comp_counter
 131                     components[comp_counter].add((x, y))
 132                     comp_counter += 1
 133                 elif len(s) == 2:
 134                     s.remove(0)
 135                     c = s.pop()
 136                     new_image_l[x, y] = c
 137                     components[c].add((x,y))
 138                 else:
 139                     s.remove(0)
 140                     c1 = s.pop()
 141                     components[c1].add((x, y))
 142                     new_image_l[x, y] = c1
 143                     for c2 in s:
 144                         for (x1, y1) in components[c2]:
 145                             new_image_l[x1, y1] = c1
 146                         components[c1] = components[c1] | components[c2]
 147                         components[c2] = None
 148
 149     new_image = Image.new('L', image.size)
 150     new_image_l = new_image.load()
 151
 152     for component in components:
 153         if component:
 154             x_c = 0
 155             y_c = 0
 156             c = 0
 157             for (x, y) in component:
 158                 x_c += x
 159                 y_c += y
 160                 c += 1
 161             new_image_l[int(round(float(x_c)/c)), int(round(float(y_c)/c))] = 255
 162
 163
 164     return new_image