comments for hough and geometry

[imago.git] / imago_pack / hough.py

diff --git a/imago_pack/hough.py b/imago_pack/hough.py
index 2f6e63f..deeb9d8 100644 (file)
--- a/imago_pack/hough.py
+++ b/imago_pack/hough.py
@@ -7,14 +7,20 @@ from PIL import Image
 import pcf
 
 class Hough:
+    """Hough transform.
+
+    This class stores the transformed image and metainformation.
+    """
     def __init__(self, size, dt, init_angle, image):
-        self.size = size
-        self.dt = dt
+        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):
+        """Create Hough transform of the *image* with default parameters."""
+        # TODO rename to transform?
         size = image.size
         dt = pi / size[1]
         initial_angle = (pi / 4) + (dt / 2)
@@ -27,12 +33,15 @@ class Hough:
                      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):
+        # TODO what is this?
         im_l = self.image.load()
         lines1 = []
         for x in xrange(self.size[0] / 2):
@@ -47,6 +56,7 @@ 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 +66,8 @@ 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)