Merge pull request #39 from matthewtownson/master

Fixed bug in centroiders and updated test

Author: andrewpaulreeves

aotools/image_processing/centroiders.py

@@ -9,7 +9,7 @@
 import numpy
 
 
-def correlation_centroid(im, ref, threshold):
+def correlation_centroid(im, ref, threshold=0.):
     """
     Correlation Centroider, currently only works for 3d im shape.
     Performs a simple thresholded COM on the correlation.
@@ -80,9 +80,6 @@ def centreOfGravity(img, threshold=0, **kwargs):
         y_centroid = (y_cent*img).sum(-1).sum(-1)/img.sum(-1).sum(-1)
         x_centroid = (x_cent*img).sum(-1).sum(-1)/img.sum(-1).sum(-1)
 
-    y_centroid+=0.5
-    x_centroid+=0.5
-
     return numpy.array([x_centroid, y_centroid])
 
 

test/test_centroiders.py

@@ -15,6 +15,11 @@ def test_centreOfGravity_many():
     assert(com.shape[0] == 2)
     assert(com.shape[1] == 5)
 
+def test_centreOfGravity_value():
+    img = numpy.zeros((1, 5, 5))
+    img[0, 1:3, 2:4] = 1.
+    centroid = image_processing.centreOfGravity(img)
+    numpy.testing.assert_almost_equal(centroid, numpy.array([[2.5], [1.5]]))
 
 def test_brightestPxl_single():
     img = numpy.random.random((10, 10))