Merge pull request jdf#111 from AnishHota/AnishHota/error-tutorial

[#258]Updated index.html to process only the rectangle instead of the entire image

Author: Jonathan Feinberg

Tutorials/pixels/index.html

@@ -586,8 +586,8 @@ <h3>Level II: Pixel Group Processing</h3>
     matrixsize = 3
     loadPixels()
     # Begin our loop for every pixel
-    for x in xrange(xend):
-        for y in xrange(yend):
+    for x in xrange(xstart,xend):
+        for y in xrange(ystart,yend):
             # Each pixel location (x,y) gets passed into a function called convolution() 
             # which returns a new color value to be displayed.
             c = convolution(x,y,matrix,matrixsize,img)