TST: Add tests for image_label2rgb

skimage/color/tests/test_colorlabel.py

@@ -0,0 +1,67 @@
+import itertools
+
+import numpy as np
+from numpy import testing
+from skimage.color.colorlabel import image_label2rgb
+from numpy.testing import assert_array_almost_equal as assert_close
+
+
+def test_shape_mismatch():
+    image = np.ones((3, 3))
+    label = np.ones((2, 2))
+    testing.assert_raises(ValueError, image_label2rgb, image, label)
+
+
+def test_rgb():
+    image = np.ones((1, 3))
+    label = np.arange(3).reshape(1, -1)
+    colors = [(1, 0, 0), (0, 1, 0), (0, 0, 1)]
+    # Set alphas just in case the defaults change
+    rgb = image_label2rgb(image, label, colors=colors, alpha=1, image_alpha=1)
+    assert_close(rgb, [colors])
+
+
+def test_alpha():
+    image = np.random.uniform(size=(3, 3))
+    label = np.random.randint(0, 9, size=(3, 3))
+    # If we set `alpha = 0`, then rgb should match image exactly.
+    rgb = image_label2rgb(image, label, alpha=0, image_alpha=1)
+    assert_close(rgb[..., 0], image)
+    assert_close(rgb[..., 1], image)
+    assert_close(rgb[..., 2], image)
+
+
+def test_image_alpha():
+    image = np.random.uniform(size=(1, 3))
+    label = np.arange(3).reshape(1, -1)
+    colors = [(1, 0, 0), (0, 1, 0), (0, 0, 1)]
+    # If we set `image_alpha = 0`, then rgb should match label colors exactly.
+    rgb = image_label2rgb(image, label, colors=colors, alpha=1, image_alpha=0)
+    assert_close(rgb, [colors])
+
+
+def test_color_names():
+    image = np.ones((1, 3))
+    label = np.arange(3).reshape(1, -1)
+    cnames = ['red', 'lime', 'blue']
+    colors = [(1, 0, 0), (0, 1, 0), (0, 0, 1)]
+    # Set alphas just in case the defaults change
+    rgb = image_label2rgb(image, label, colors=cnames, alpha=1, image_alpha=1)
+    assert_close(rgb, [colors])
+
+
+def test_bg_and_color_cycle():
+    image = np.zeros((1, 10))  # dummy image
+    label = np.arange(10).reshape(1, -1)
+    colors = [(1, 0, 0), (0, 0, 1)]
+    bg_color = (0, 0, 0)
+    rgb = image_label2rgb(image, label, bg_label=0, bg_color=bg_color,
+                          colors=colors, alpha=1)
+    assert_close(rgb[0, 0], bg_color)
+    for pixel, color in zip(rgb[0, 1:], itertools.cycle(colors)):
+        assert_close(pixel, color)
+
+
+if __name__ == '__main__':
+    testing.run_module_suite()
+