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