ImProc ass1: Replaced separate figures with subplots.

improc/ass1/lowcontrast.py

 from pylab import clf, histogram, imshow, imread, bar, diff, xlim, show, \
-    figure, amin, amax
+    subplot, amin, amax
 
 i = 1
 
 def show_hist(a):
     global i
-    figure(i)
+    subplot(2, 2, i)
     imshow(a, vmin=0, vmax=1)
     h, be = histogram(a.flatten(), bins=40)
 
-    figure(i + 1)
+    subplot(2, 2, i + 1)
     bar(be[:-1], h, width=diff(be)[0])
     xlim((0, 1))
     i += 2