filters.py

   1 from PIL import Image
   2
   3 from commons import clear
   4
   5 def edge_detection(image):
   6     image_l = image.load()
   7     new_image = Image.new('L', image.size)
   8     new_image_l = new_image.load()
   9     clear()
  10     print "edge detection"
  11     for x in range(2, image.size[0] - 2):
  12         for y in range(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     clear()
  30     print "peak extraction"
  31     for x in range(2, image.size[0] - 2):
  32         for y in range(2, image.size[1] - 2):
  33             pix = (sum([sum([
  34                 - image_l[a, b]
  35                     for b in range(y - 2, y + 3)])
  36                     for a in range(x - 2, x + 3)])
  37                 + (16 * image_l[x, y]))
  38             if pix > 255:
  39                 pix = 255
  40             if pix < 0:
  41                 pix = 0
  42             new_image_l[x, y] = pix
  43     return new_image
  44
  45 def high_pass(image, height):
  46     image_l = image.load()
  47     new_image = Image.new('L', image.size)
  48     new_image_l = new_image.load()
  49     clear()
  50     print "high pass filter"
  51     for x in xrange(image.size[0]):
  52         for y in xrange(image.size[1]):
  53             if image_l[x, y] < height:
  54                 new_image_l[x, y] = 0
  55             else:
  56                 new_image_l[x, y] = image_l[x, y]
  57
  58     return new_image