From 7f100ac1b465d088195802525bba2d3a557c481a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Johannes=20Sch=C3=B6nberger?= <hannesschoenberger@gmail.com>
Date: Sat, 6 Oct 2012 15:23:23 +0200
Subject: [PATCH] Full test coverage for image pyramids

---
 skimage/transform/tests/test_pyramids.py | 49 +++++++++++++++++++-----
 1 file changed, 40 insertions(+), 9 deletions(-)

diff --git a/skimage/transform/tests/test_pyramids.py b/skimage/transform/tests/test_pyramids.py
index 611ecdec..dd976a7b 100644
--- a/skimage/transform/tests/test_pyramids.py
+++ b/skimage/transform/tests/test_pyramids.py
@@ -1,41 +1,72 @@
-from numpy.testing import assert_array_equal, run_module_suite
+from numpy.testing import assert_array_equal, assert_raises, run_module_suite
 from skimage import data
-from skimage.transform import (pyramid_reduce, pyramid_expand,
-                               pyramid_gaussian, pyramid_laplacian)
+from skimage.transform import pyramids
 
 
 image = data.lena()
+image_gray = image[..., 0]
 
 
 def test_pyramid_reduce():
+    # RGB image
     rows, cols, dim = image.shape
-    out = pyramid_reduce(image, downscale=2)
+    out = pyramids.pyramid_reduce(image, downscale=2)
     assert_array_equal(out.shape, (rows / 2, cols / 2, dim))
 
+    # grayscale image
+    rows, cols = image_gray.shape
+    out = pyramids.pyramid_reduce(image_gray, downscale=2)
+    assert_array_equal(out.shape, (rows / 2, cols / 2))
+
 
 def test_pyramid_expand():
+    # RGB image
     rows, cols, dim = image.shape
-    out = pyramid_expand(image, upscale=2)
+    out = pyramids.pyramid_expand(image, upscale=2)
     assert_array_equal(out.shape, (rows * 2, cols * 2, dim))
 
+    # grayscale image
+    rows, cols = image_gray.shape
+    out = pyramids.pyramid_expand(image_gray, upscale=2)
+    assert_array_equal(out.shape, (rows * 2, cols * 2))
+
 
 def test_build_gaussian_pyramid():
+    # RGB image
     rows, cols, dim = image.shape
-    pyramid = pyramid_gaussian(image, downscale=2)
-
+    pyramid = pyramids.pyramid_gaussian(image, downscale=2)
     for layer, out in enumerate(pyramid):
         layer_shape = (rows / 2 ** layer, cols / 2 ** layer, dim)
         assert_array_equal(out.shape, layer_shape)
 
+    # grayscale image
+    rows, cols = image_gray.shape
+    pyramid = pyramids.pyramid_gaussian(image_gray, downscale=2)
+    for layer, out in enumerate(pyramid):
+        layer_shape = (rows / 2 ** layer, cols / 2 ** layer)
+        assert_array_equal(out.shape, layer_shape)
+
 
 def test_build_laplacian_pyramid():
+    # RGB image
     rows, cols, dim = image.shape
-    pyramid = pyramid_laplacian(image, downscale=2)
-
+    pyramid = pyramids.pyramid_laplacian(image, downscale=2)
     for layer, out in enumerate(pyramid):
         layer_shape = (rows / 2 ** layer, cols / 2 ** layer, dim)
         assert_array_equal(out.shape, layer_shape)
 
+    # grayscale image
+    rows, cols = image_gray.shape
+    pyramid = pyramids.pyramid_laplacian(image_gray, downscale=2)
+    for layer, out in enumerate(pyramid):
+        layer_shape = (rows / 2 ** layer, cols / 2 ** layer)
+        assert_array_equal(out.shape, layer_shape)
+
+
+def test_check_factor():
+    assert_raises(ValueError, pyramids._check_factor, 0.99)
+    assert_raises(ValueError, pyramids._check_factor, - 2)
+
 
 if __name__ == "__main__":
     run_module_suite()