preprocessor">#ifdef BOOST_GIL_IO_ENABLE_GRAY_ALPHA</span></div><div class="line"><a name="l00066"></a><span class="lineno">   66</span>&#160;<span class="keyword">using</span> gray_alpha8_image_t = image&lt;gray_alpha8_pixel_t, false&gt;;</div><div class="line"><a name="l00067"></a><span class="lineno">   67</span>&#160;<span class="keyword">using</span> gray_alpha16_image_t = image&lt;gray_alpha16_pixel_t, false&gt;;</div><div class="line"><a name="l00068"></a><span class="lineno">   68</span>&#160;<span 