)</span><span class="o">+</span><span class="n">loc</span><span class="p">(</span><span class="mi">0</span><span class="p">,</span><span class="mi">1</span><span class="p">))</span><span class="o">/</span><span class="mi">2</span><span class="p">;</span>     <span class="c1">// set pixel (10,24) to the average of (10,23) and (10,25) (grayscale pixels only)</span>
<span class="o">*</span><span class="n">loc</span><span class="o">=</span><span class="p">(</span><span class="n">loc</span><span class="p">[</spa