ImProc: Added assignment 3.

improc/ass3/intersect.py

+from pylab import zeros, imread
+
+def col2bin(color):
+    return tuple(map(lambda x: round(x - 1), color))
+
+def domainIterator(image):
+    for x in xrange(image.shape[0]):
+        for y in xrange(image.shape[1]):
+            yield x, y
+
+def colHist(image, bins, model):
+    h = zeros(bins)
+    image *= bins
+
+    if model == 'rgb':
+        image /= 255
+    elif model == 'rgba':
+        pass
+
+    for p in domainIterator(image):
+        h[col2bin(image[p])] += 1
+
+    return h
+
+def histogramIntersect(h1, h2):
+    if h1.shape != h2.shape:
+        raise ValueError('Shape mismatch between h1 and h2.')
+
+    match = 0
+
+    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])
+
+    return match / h2.sum()
+
+# Create table of intersections
+bins = [8] * 3
+db = map(lambda x: imread('database/%d.jpg' % x), range(1, 21))
+table = zeros((len(db), len(db)))
+enum = enumerate(db)
+
+for i, im1 in enum:
+    for j, im2 in enum:
+        table[i, j] = histogramIntersect(colHist(im1, bins, 'rgb'),
+                                         colHist(im2, bins, 'rgb'))
+
+print table