improc ass2 code cleanup.

improc/ass2/interpolation.py

@@ -6,33 +6,32 @@ def inImage(image, x, y):
     return x >= 0 and y >= 0 and x < image.shape[0] and y < image.shape[1]
 
 def pV(image, x, y, method):
-    global bgcolor
-
-    if inImage(image, x, y):
-        if method == 'nearest':
-            return image[round(x)][round(y)]
-        elif method == 'linear':
-            x1 = floor(x)
-            x2 = ceil(x)
-            y1 = floor(y)
-            y2 = ceil(y)
-
-            return image[x1][y1] * (x2 - x) * (y2 - y) \
-                   + image[x2][y1] * (x - x1) * (y2 - y) \
-                   + image[x1][y2] * (x2 - x) * (y - y1) \
-                   + image[x2][y2] * (x - x1) * (y - y1)
-        else:
-            print 'Interpolation method "%s" is not supported' % method
-    else:
+    if not inImage(image, x, y):
         return bgcolor
 
+    if method == 'nearest':
+        return image[round(x)][round(y)]
+
+    if method == 'linear':
+        x1 = floor(x)
+        x2 = ceil(x)
+        y1 = floor(y)
+        y2 = ceil(y)
+
+        return image[x1][y1] * (x2 - x) * (y2 - y) \
+            + image[x2][y1] * (x - x1) * (y2 - y) \
+            + image[x1][y2] * (x2 - x) * (y - y1) \
+            + image[x2][y2] * (x - x1) * (y - y1)
+
+    raise ValueError, 'Interpolation method "%s" is not supported' % method
+
 if __name__ == '__main__':
     from pylab import linspace, show, imread, plot, array
 
     """Profile of an image along line in n points."""
     def profile(image, x0, y0, x1, y1, n, method):
-        return array([pV(image, x, y, method) for x, y in zip(linspace(x0, \
-            x1, n), linspace(y0, y1, n))])
+        dataset = zip(linspace(x0, x1, n), linspace(y0, y1, n))
+        return array([pV(image, x, y, method) for x, y in dataset])
 
     a = imread('cameraman.png')
     for method in ['nearest', 'linear']: