me="l00086"></a>00086     }
<a name="l00087"></a>00087 };
<a name="l00088"></a>00088 
<a name="l00089"></a>00089 <span class="keyword">template</span> &lt;<span class="keyword">typename</span> GrayChannel, <span class="keyword">typename</span> RedChannel, <span class="keyword">typename</span> GreenChannel, <span class="keyword">typename</span> BlueChannel&gt;
<a name="l00090"></a>00090 <span class="keyword">typename</span> channel_traits&lt;GrayChannel&gt;::value_type rgb_to_luminance(<span class="keyword">