imago_pack/linef.py

   1 """Go image recognition lines-finding module"""
   2
   3 from functools import partial
   4 import sys
   5 from math import sin, cos, pi
   6
   7 try:
   8     import Image, ImageDraw
   9 except ImportError, msg:
  10     print >> sys.stderr, msg
  11     sys.exit(1)
  12
  13 import filters
  14 from hough import Hough
  15
  16 def find_lines(image, show_all, do_something, verbose):
  17
  18     if verbose:
  19         print >> sys.stderr, "preprocessing"
  20
  21     if show_all:
  22         do_something(image, "original image")
  23
  24     im_l = image.convert('L')
  25     if show_all:
  26         do_something(im_l, "ITU-R 601-2 luma transform")
  27
  28     if verbose:
  29         print >> sys.stderr, "edge detection"
  30
  31     im_edges = filters.edge_detection(im_l)
  32     if show_all:
  33         do_something(im_edges, "edge detection")
  34
  35     im_h = filters.high_pass(im_edges, 100)
  36     if show_all:
  37         do_something(im_h, "high pass filters")
  38
  39     if verbose:
  40         print >> sys.stderr, "hough transform"
  41
  42     im_hough = Hough.Transform(im_h)
  43     if show_all:
  44         do_something(im_hough.image, "hough transform")
  45
  46    # im_hough.image = filters.peaks(im_hough.image)
  47    # if show_all:
  48    #     do_something(im_hough.image, "peak extraction")
  49
  50     im_h2 = im_hough.apply_filter(partial(filters.high_pass, height=96))
  51     if show_all:
  52         do_something(im_h2.image, "second high pass filters")
  53
  54     im_h2 = im_h2.apply_filter(filters.components2)
  55     if show_all:
  56         do_something(im_h2.image, "components centers")
  57
  58     if verbose:
  59         print >> sys.stderr, "second hough transform"
  60
  61     # im_hough might be used instead im_h2, but at the moment it brings a lot of
  62     # noise to the second transform, which later confuses the center-finding
  63     # mechanism (which is not very robust yet)
  64     im_hough2 = Hough.Transform(im_h2.image)
  65     if show_all:
  66         do_something(im_hough2.image, "second hough transform")
  67
  68     im_h3 = im_hough2.apply_filter(partial(filters.high_pass, height=120))
  69     if show_all:
  70         do_something(im_h3.image, "third high pass filter")
  71
  72     im_h3 = im_h3.apply_filter(filters.components)
  73     if show_all:
  74         do_something(im_h3.image, "half centers")
  75
  76     if verbose:
  77         print >> sys.stderr, "finding the grid"
  78
  79     lines_m = im_h3.all_lines_h()
  80     lines = []
  81     im_c = im_h2.image.convert('RGB').convert('RGB', (1, 0.5, 0.5, 0))
  82     draw_c = ImageDraw.Draw(im_c)
  83     bounds = []
  84
  85     for line_l in lines_m:
  86         im_line = Image.new('L', im_h2.size)
  87         draw = ImageDraw.Draw(im_line)
  88         line_points = set()
  89         for line in line_l:
  90             draw.line(line_from_angl_dist(line, im_h2.size), fill=255, width=7)
  91             draw_c.line(line_from_angl_dist(line, im_c.size),
  92                         fill=(70, 70, 70), width=7)
  93             for p in combine(im_h2.image, im_line):
  94                 line_points.add(p)
  95         for point in line_points:
  96             draw_c.point(point, fill=(120, 255, 120))
  97         lines.append(im_hough.lines_from_list(line_points))
  98         line_points = list(line_points)
  99         line_points.sort()
 100         bounds += [line_points[0], line_points[-1]]
 101
 102     if show_all:
 103         do_something(im_c, "hough x lines")
 104
 105     image_g = image.copy()
 106     draw = ImageDraw.Draw(image_g)
 107     for line in [l for s in lines for l in s]:
 108         draw.line(line_from_angl_dist(line, image.size), fill=(120, 255, 120))
 109     if show_all:
 110         do_something(image_g, "lines")
 111
 112     return lines, lines_m[0][0], lines_m[1][0], bounds, im_hough
 113
 114 def combine(image1, image2):
 115     im_l1 = image1.load()
 116     im_l2 = image2.load()
 117
 118     on_both = []
 119
 120     for x in xrange(image1.size[0]):
 121         for y in xrange(image1.size[1]):
 122             if im_l1[x, y] and im_l2[x, y]:
 123                 on_both.append((x, y))
 124     return on_both
 125
 126 def line_from_angl_dist((angle, distance), size):
 127     if pi / 4 < angle < 3 * pi / 4:
 128         y1 = - size[1] / 2
 129         x1 = int(round((y1 * cos(angle) + distance) / sin(angle))) + size[0] / 2
 130         y2 = size[1] / 2
 131         x2 = int(round((y2 * cos(angle) + distance) / sin(angle))) + size[0] / 2
 132         return [(x1, 0), (x2, size[1])]
 133     else:
 134         x1 = - size[0] / 2
 135         y1 = int(round((x1 * sin(angle) - distance) / cos(angle))) + size[1] / 2
 136         x2 = size[0] / 2
 137         y2 = int(round((x2 * sin(angle) - distance) / cos(angle))) + size[1] / 2
 138         return [(0, y1), (size[0], y2)]