X-Git-Url: http://git.tomasm.cz/imago.git/blobdiff_plain/6d19451cd1ebad960d015a79f27ab95f86c31d61..71f8dfb76a3534132d68e3f65af7535e723cc44b:/imago_pack/hough.py?ds=inline

diff --git a/imago_pack/hough.py b/imago_pack/hough.py
index 77f30b2..6235b5d 100644
--- a/imago_pack/hough.py
+++ b/imago_pack/hough.py
@@ -7,33 +7,44 @@ from PIL import Image
 import pcf
 
 class Hough:
-    def __init__(self, size, dt, init_angle, image):
-        self.size = size # TODO is this a tuple? This language is crazy
-        self.dt = dt
+    """Hough transform.
+
+    This class stores the parameters of the transformation.
+    """
+    def __init__(self, size, dt, init_angle):
+        self.size = size # this is a tuple (width, height)
+        self.dt = dt     # this is the angle step in hough transform
         self.initial_angle = init_angle
-        self.image = image
 
     @classmethod
-    def Transform(cls, image):
+    def default(cls, image):
+        """Default parameters for Hough transform of the *image*."""
         size = image.size
         dt = pi / size[1]
         initial_angle = (pi / 4) + (dt / 2)
-        image_s = pcf.hough(size, image.tostring(), initial_angle, dt)
-        image_t = Image.fromstring('L', size, image_s)
-        return cls(size, dt, initial_angle, image_t)
+        return cls(size, dt, initial_angle)
+
+    def transform(self, image):
+        image_s = pcf.hough(self.size, image.tostring(), self.initial_angle,
+                            self.dt)
+        image_t = Image.fromstring('L', self.size, image_s)
+        return image_t
 
     def apply_filter(self, filter_f):
         return Hough(self.size, self.dt, self.initial_angle,
                      filter_f(self.image))
 
     def lines_from_list(self, p_list):
+        """Take a list of transformed points and return a list of corresponding
+        lines as (angle, distance) tuples."""
         lines = []
         for p in p_list:
             lines.append(self.angle_distance(p))
         return lines
 
-    def all_lines_h(self):
-        im_l = self.image.load()
+    def all_lines_h(self, image):
+        # TODO what is this?
+        im_l = image.load()
         lines1 = []
         for x in xrange(self.size[0] / 2):
             for y in xrange(self.size[1]):
@@ -47,6 +58,7 @@ class Hough:
         return [lines1, lines2]
 
     def all_lines(self):
+        # TODO what is this? how does it differ from the upper one?
         im_l = self.image.load()
         lines = []
         for x in xrange(self.size[0]):
@@ -56,6 +68,8 @@ class Hough:
         return lines
     
     def angle_distance(self, point):
+        """Take a point from the transformed image and return the corresponding
+        line in the original as (angle, distance) tuple."""
         return (self.dt * point[1] + self.initial_angle,
                 point[0] - self.size[0] / 2)