pan class="o">.</span><span class="n">keys</span><span class="p">())]</span>

    <span class="c1"># Calculate color difference and take account of KL:</span>
    <span class="n">DEi</span> <span class="o">=</span> <span class="p">((((</span><span class="n">jabt</span><span class="p">[</span><span class="o">...</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="n">jabr</span><span class="p">[</s