Adds histogram support to 3 channels images

Finishes support for 3 channels images.
Adds a function allowing to extract only one desired channel
Updates the example to extract all channels.

Support for 16 and 32 bits images should be tested.

Function for 3c to 1c to be added quickly!

Reported-by: Julien Lengrand-Lambert <julien@lengrand.fr>
Signed-off-by: Julien Lengrand-Lambert <julien@lengrand.fr>

tippy/tests/test_statistics.py

@@ -4,4 +4,126 @@ Created on Dec 11, 2011
 @author: Julien Lengrand-Lambert
 @email: julien@lengrand.fr
 '''
+import unittest
+import cv
 
+import tippy.statistics as st
+
+class Test(unittest.TestCase):
+
+
+    def setUp(self):
+        """
+        This method is called before each test
+        """
+        self.img_1c = cv.LoadImage("data/tippy.jpg", cv.CV_LOAD_IMAGE_GRAYSCALE) # 1 channel image 
+        self.img_3c = cv.LoadImage("data/tippy.jpg", cv.CV_LOAD_IMAGE_COLOR) # 3 channel image
+        self.img_2c = cv.CreateImage((10, 10), cv.IPL_DEPTH_8U, 2) # fake 2 channels image 
+        self.img_16s = cv.CreateImage((15, 15), cv.IPL_DEPTH_16S, 1) # Non 8 bits image
+        
+        self.val = 10 # non Image
+        self.neg_val = -10 # non Image
+        self.string = "A" # non Image
+        
+    def tearDown(self):
+        """
+        This method is called after each test
+        """
+        pass
+
+    #--- 
+    ## TESTS
+    def test_compute_histogram(self):
+        # testing input image
+        self.assertRaises(TypeError, lambda:st.Histogram(self.val) )
+        self.assertRaises(TypeError, lambda:st.Histogram(self.img_16s) )        
+        self.assertRaises(ValueError, lambda:st.Histogram(self.img_2c) )      
+        # testing bin_fact
+        self.assertRaises(ValueError, 
+                          lambda: st.Histogram(self.img_1c, self.neg_val))
+        self.assertRaises(TypeError, 
+                          lambda: st.Histogram(self.img_1c, self.string)) 
+
+        # testing min_range. It can be either negative or even.
+        self.assertRaises(TypeError, 
+                          lambda: st.Histogram(self.img_1c, self.val, self.string))     
+<<<<<<< HEAD
+
+        # testing output
+        hist_1c = st.Histogram(self.img_1c)
+        self.assertEquals(self.img_1c.nChannels, hist_1c.channels)     
+        hist_3c = st.Histogram(self.img_3c)
+        self.assertEquals(self.img_3c.nChannels, hist_3c.channels)
+
+    def test_to_tables(self):
+        # testing output size 
+        hist = st.Histogram(self.img_3c)
+        histable = hist.to_tables()
+        self.assertEqual(3, len(histable))
+        self.assertEqual(256, len(histable[0]))
+        
+    def test_channel_to_image(self):
+        hist = st.Histogram(self.img_3c)
+        # testing channel value
+        self.assertRaises(ValueError, 
+                          lambda: hist.channel_to_image(4))        
+        self.assertRaises(TypeError, 
+                          lambda: hist.channel_to_image(self.string))
+        self.assertRaises(TypeError, 
+                          lambda: hist.channel_to_image(self.neg_val))        
+=======
+
+        # testing output
+        hist_1c = st.Histogram(self.img_1c)
+        self.assertEquals(self.img_1c.nChannels, hist_1c.channels)     
+        hist_3c = st.Histogram(self.img_3c)
+        self.assertEquals(self.img_3c.nChannels, hist_3c.channels)
+
+    def test_hist2table(self):
+        # testing output size 
+        hist = st.Histogram(self.img_3c)
+        histable = hist.hist2table()
+        self.assertEqual(3, len(histable))
+        self.assertEqual(256, len(histable[0]))
+        
+    def test_hist2image(self):     
+        hist = st.Histogram(self.img_1c)
+>>>>>>> 335108ecf6cb601da09717b94407e54e677b9cee
+        # testing scale inputs 
+        self.assertRaises(TypeError, 
+                          lambda: hist.channel_to_image(1, self.string))
+        self.assertRaises(TypeError, 
+                          lambda: hist.channel_to_image(1, self.neg_val))
+        self.assertRaises(TypeError, 
+                          lambda: hist.channel_to_image(1, self.val, self.string))
+        self.assertRaises(TypeError, 
+                          lambda: hist.channel_to_image(1, self.val, self.neg_val))
+        # testing range inputs
+        self.assertRaises(TypeError, 
+                          lambda: hist.channel_to_image(1, self.val, self.val, self.string))
+        self.assertRaises(TypeError, 
+                          lambda: hist.channel_to_image(1, self.val, self.val, self.neg_val))
+
+    def test_to_images(self):
+        hist = st.Histogram(self.img_3c)
+        # testing scale inputs 
+        self.assertRaises(TypeError, 
+                          lambda: hist.to_images(self.string))
+        self.assertRaises(TypeError, 
+                          lambda: hist.to_images(self.neg_val))
+        self.assertRaises(TypeError, 
+                          lambda: hist.to_images(self.val, self.string))
+        self.assertRaises(TypeError, 
+                          lambda: hist.to_images(self.val, self.neg_val))
+        # testing range inputs
+        self.assertRaises(TypeError, 
+                          lambda: hist.to_images(self.val, self.val, self.string))
+        self.assertRaises(TypeError, 
+                          lambda: hist.to_images(self.val, self.val, self.neg_val))
+
+        # testing outputs
+        self.assertEqual(hist.channels, len(hist.to_images()))
+        
+#if __name__ == "__main__":
+    #import sys;sys.argv = ['', 'Test.testName']
+    #unittest.main()