age_t = bit_aligned_image1_type&lt;24, gray_layout_t&gt;::type;</div><div class="line"><a name="l00052"></a><span class="lineno">   52</span>&#160;</div><div class="line"><a name="l00053"></a><span class="lineno">   53</span>&#160;<span class="keyword">using</span> gray64f_pixel_t = pixel&lt;double, gray_layout_t&gt;;</div><div class="line"><a name="l00054"></a><span class="lineno">   54</span>&#160;</div><div class="line"><a name="l00055"></a><span class="lineno">   55</span>&#160;<span class="preprocessor