filters.py

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