eChannel&amp; blue)<span class="keyword"> const </span>{
<a name="l00073"></a>00073         <span class="keywordflow">return</span> channel_convert&lt;GrayChannelValue&gt;( <a class="code" href="g_i_l_0620.html" title="A channel adaptor that modifies the range of the source channel. Models: ChannelValueConcept...">bits32f</a>(
<a name="l00074"></a>00074             channel_convert&lt;bits32f&gt;(red  )*0.30f + 
<a name="l00075"></a>00075             channel_convert&lt;bits32f&gt;(green)*0.59f + 
<a name="l0