FIX: Testing for ubyte and float images. Input dtypes are converted beforehand.

skimage/color/colorconv.py

@@ -769,7 +769,7 @@ def rgb2hed(rgb):
     >>> ihc = data.ihc()
     >>> ihc_hed = rgb2hed(ihc)
     """
-    rgb = rgb.astype(float) + 1
+    rgb = dtype.img_as_float(rgb) + 1
     hed = np.dot(np.reshape(-np.log(rgb), (-1, 3)), hed_from_rgb)
     return np.reshape(hed, rgb.shape)
 
@@ -807,6 +807,7 @@ def hed2rgb(hed):
     >>> ihc_hed = rgb2hed(ihc)
     >>> ihc_rgb = hed2rgb(ihc_hed)
     """
+    hed = dtype.img_as_float(hed)
     logrgb1 = np.dot(-np.reshape(hed, (-1, 3)), rgb_from_hed)
     rgb1 = np.exp(logrgb1)
     return np.reshape(rgb1 - 1, hed.shape)

skimage/color/tests/test_colorconv.py

@@ -122,17 +122,14 @@ class TestColorconv(TestCase):
         img_rgb = img_as_float(self.img_rgb)
         assert_array_almost_equal(xyz2rgb(rgb2xyz(img_rgb)), img_rgb)
 
-    # RGB<->HED roundtrip
+    # RGB<->HED roundtrip with ubyte image
     def test_hed_rgb_roundtrip(self):
-        img_rgb = np.array([[[97, 105, 152],
-                             [217, 187, 225],
-                             [117, 107, 168]],
-                            [[217, 187, 225],
-                             [176, 135, 83],
-                             [234, 144, 205]],
-                            [[97, 105, 152],
-                             [117, 107, 168], 
-                             [217, 187, 225]]], dtype=np.uint8)
+        img_rgb = self.img_rgb
+        assert_array_almost_equal(hed2rgb(rgb2hed(img_rgb)), img_as_float(img_rgb))
+
+    # RGB<->HED roundtrip with float image
+    def test_hed_rgb_float_roundtrip(self):
+        img_rgb = img_as_float(self.img_rgb)
         assert_array_almost_equal(hed2rgb(rgb2hed(img_rgb)), img_rgb)
 
     # RGB to RGB CIE