Adding histogram example to arrayfire

Author: pavanky

examples/graphics/histogram.py

@@ -0,0 +1,37 @@
+#!/usr/bin/python
+
+#######################################################
+# Copyright (c) 2015, ArrayFire
+# All rights reserved.
+#
+# This file is distributed under 3-clause BSD license.
+# The complete license agreement can be obtained at:
+# http://arrayfire.com/licenses/BSD-3-Clause
+########################################################
+
+import arrayfire as af
+import sys
+import os
+
+if __name__ == "__main__":
+
+    if (len(sys.argv) == 1):
+        raise RuntimeError("Expected to the image as the first argument")
+
+    if not os.path.isfile(sys.argv[1]):
+        raise RuntimeError("File %s not found" % sys.argv[1])
+
+    if (len(sys.argv) >  2):
+        af.set_device(int(sys.argv[2]))
+
+    af.info()
+
+    hist_win = af.Window(512, 512, "3D Plot example using ArrayFire")
+    img_win  = af.Window(480, 640, "Input Image")
+
+    img = af.cast(af.load_image(sys.argv[1]), af.Dtype.u8)
+    hist = af.histogram(img, 256, 0, 255)
+
+    while (not hist_win.close()) and (not img_win.close()):
+        hist_win.hist(hist, 0, 255)
+        img_win.image(img)