diff --git a/tippy/data/gnu.jpg b/tippy/data/gnu.jpg
new file mode 100644
index 0000000..0c0cca9
Binary files /dev/null and b/tippy/data/gnu.jpg differ
diff --git a/tippy/segmentations.py b/tippy/segmentations.py
index 05936fa..f15c3db 100644
--- a/tippy/segmentations.py
+++ b/tippy/segmentations.py
@@ -8,6 +8,7 @@ Created on Nov 26, 2011
 '''
 import sys
 import cv
+import numpy
 
 def simple_region_growing(img, seed, threshold=1):
     """
@@ -31,7 +32,7 @@ def simple_region_growing(img, seed, threshold=1):
         raise ValueError("(%s) Positive value expected!" % (sys._getframe().f_code.co_name))
     # seed tests
     if not((isinstance(seed, tuple)) and (len(seed) is 2) ) : 
-        raise ValueError("(%s) (x, y) variable expected!" % (sys._getframe().f_code.co_name))
+        raise TypeError("(%s) (x, y) variable expected!" % (sys._getframe().f_code.co_name))
     
     dims = cv.GetSize(img)
     if (seed[0] or seed[1] ) < 0 :
@@ -56,7 +57,7 @@ def simple_region_growing(img, seed, threshold=1):
     cur_pix = [seed[0], seed[1]]
 
     #Spreading
-    while(dist<thres and size<pix_area):
+    while(dist<threshold and size<pix_area):
     #adding pixels
         for j in range(4):
             #select new candidate
diff --git a/tippy/tests/test_segmentation.py b/tippy/tests/test_segmentation.py
index d3d7925..550c64a 100644
--- a/tippy/tests/test_segmentation.py
+++ b/tippy/tests/test_segmentation.py
@@ -20,10 +20,10 @@ class Test(unittest.TestCase):
         self.img_3c = cv.LoadImage("../data/tippy.jpg", cv.CV_LOAD_IMAGE_COLOR) # 3 channel image 
         self.img_16s = cv.CreateImage((15, 15), cv.IPL_DEPTH_16S, 1) # Non 8 bits image
         self.fake_img = 10 # non Image
-    
+
         self.dims = cv.GetSize(self.img_1c)
         
-        self.neg_thres = -0
+        self.neg_thres = -10
         self.bad_thres = "A"
         
         self.seed = (10, 10)
@@ -53,10 +53,14 @@ class Test(unittest.TestCase):
         self.assertRaises(TypeError, lambda: se.simple_region_growing(self.img_1c, self.bad_seed))
         self.assertRaises(TypeError, lambda: se.simple_region_growing(self.img_1c, self.long_seed))
         # output test
-        out_img = simple_region_growing(self.img_1c, self.seed)
+        out_img = se.simple_region_growing(self.img_1c, self.seed)
         self.assertEqual(out_img.depth, cv.IPL_DEPTH_8U)
         self.assertEqual(out_img.nChannels, 1)
-        self.assertEqual(cv.GetSize(out_img), cv.GetSize(self.img_1C))
+        self.assertEqual(cv.GetSize(out_img), cv.GetSize(self.img_1c))
+        # function result tests
+        img_gnu = cv.LoadImage("../data/gnu.jpg", cv.CV_LOAD_IMAGE_GRAYSCALE) # 1 channel image 
+        out_img = se.simple_region_growing(img_gnu, seed=(70, 106), threshold=20)
+        self.assertEqual(cv.CountNonZero(out_img), 584)
            
 #if __name__ == "__main__":
     #import sys;sys.argv = ['', 'Test.testName']