ImProc ass3: Added some comments.

improc/ass3/intersect.py

@@ -3,14 +3,17 @@ from numpy import zeros
 from matplotlib.pyplot import imread
 
 def col2bin(color):
+    """Get the histogram bin coordinates of a color."""
     return tuple(map(lambda x: round(x - 1), color))
 
 def domainIterator(image):
+    """Pixel iterator for colHist."""
     for x in xrange(image.shape[0]):
         for y in xrange(image.shape[1]):
             yield x, y
 
 def colHist(image, bins, model):
+    """Create the color histogram of an image."""
     h = zeros(tuple(bins))
     use = image.astype(float) * bins
 
@@ -25,20 +28,22 @@ def colHist(image, bins, model):
     return h
 
 def histogramIntersect(h1, h2):
+    """Calculate the intersection between two color histograms."""
     if h1.shape != h2.shape:
-        raise ValueError('Shape mismatch between h1 and h2.')
+        raise ValueError('Histograms h1 and h2 are not aligned.')
 
     match = 0
-    #print h1, h2
 
+    # Add the minimum of each bin to the result
     for r in xrange(h1.shape[0]):
         for g in xrange(h1.shape[1]):
             for b in xrange(h1.shape[2]):
                 match += min(h1[r, g, b], h2[r, g, b])
 
+    # Normalize by dividing by the number of pixels
     return match / h2.sum()
 
-# Create table of intersections
+# Create table of intersections of images in the database
 if __name__ == '__main__':
     bins = [8] * 3
     db = map(lambda x: imread('database/%d.jpg' % x), range(1, 21))
@@ -46,7 +51,7 @@ if __name__ == '__main__':
 
     for i, im in enumerate(db):
         for j in xrange(i + 1, len(db)):
-            #print 'comparing', i, j
+            print 'comparing', i, j
             table[i, j] = histogramIntersect(colHist(im, bins, 'rgb'),
                                              colHist(db[j], bins, 'rgb'))