annel_invert_algorithm.html#gabbbc7b27d9f61ff45cf5ea7ac21051f5">channel_invert</a>(</div><div class="line"><a name="l00236"></a><span class="lineno">  236</span>&#160;                       detail::rgb_to_luminance&lt;<span class="keyword">typename</span> color_element_type&lt;P1,black_t&gt;::type&gt;(</div><div class="line"><a name="l00237"></a><span class="lineno">  237</span>&#160;                            <a class="code" href="group___color_base_algorithm_color.html#gab2d1dda637cb2b7c32cc87f199ea1dc0"