Add test cases for gabor filter

skimage/filter/tests/test_gabor.py

@@ -0,0 +1,35 @@
+import numpy as np
+from numpy.testing import assert_almost_equal, assert_array_almost_equal
+
+from skimage.filter import gabor_kernel, gabor_filter
+
+
+def test_gabor_kernel_sum():
+    for sigmax in range(1, 10, 2):
+        for sigmay in range(1, 10, 2):
+            for frequency in range(0, 10, 2):
+                kernel = gabor_kernel(sigmax, sigmay, frequency+0.1, 0)
+                # make sure gaussian distribution is covered nearly 100%
+                assert_almost_equal(np.abs(kernel).sum(), 1, 2)
+
+
+def test_gabor_kernel_theta():
+    for sigmax in range(1, 10, 2):
+        for sigmay in range(1, 10, 2):
+            for frequency in range(0, 10, 2):
+                for theta in range(0, 10, 2):
+                    kernel0 = gabor_kernel(sigmax, sigmay, frequency+0.1, theta)
+                    kernel180 = gabor_kernel(sigmax, sigmay, frequency,
+                                             theta+np.pi)
+
+                    assert_array_almost_equal(np.abs(kernel0),
+                                              np.abs(kernel180))
+
+
+def test_gabor_filter():
+    real, imag = gabor_filter(np.random.random((100, 100)), 1, 1, 1, 1)
+
+
+if __name__ == "__main__":
+    from numpy import testing
+    testing.run_module_suite()