From c1b72ea638119a7755f678897d6a2b7d6859bb15 Mon Sep 17 00:00:00 2001
From: andy <andy@marvin>
Date: Tue, 27 Sep 2011 21:11:30 +0200
Subject: [PATCH] use dtype.img_as_float in _convert for colorspaces. All
 conversions are done as matrix multiplications with floats, so this is the
 only way not to lose precision.

---
 scikits/image/color/colorconv.py | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/scikits/image/color/colorconv.py b/scikits/image/color/colorconv.py
index 6393eb05..b1d4b320 100644
--- a/scikits/image/color/colorconv.py
+++ b/scikits/image/color/colorconv.py
@@ -50,6 +50,7 @@ __docformat__ = "restructuredtext en"
 
 import numpy as np
 from scipy import linalg
+from ..util import dtype
 
 
 def convert_colorspace(arr, fromspace, tospace):
@@ -299,9 +300,10 @@ def _convert(matrix, arr):
 
     Returns
     -------
-    out : ndarray
+    out : ndarray, dtype=float
         The converted array.
     """
+    arr = dtype.img_as_float(arr)
     arr = _prepare_colorarray(arr)
     arr = np.swapaxes(arr, 0, 2)
     oldshape = arr.shape