Batch script - Compare 2 directories of pictures, copy and resize only the non-existing files
<p>I have 2 directories of jpg pictures (about 15.000 files), <code>%source%</code> and <code>%target%</code>, each with theirs subdirectories:</p>

<ul>
<li><code>%source%</code> is the directory where I keep the files in full resolution.</li>
<li><code>%target%</code> is the directory where I want to keep the same files present in %target%, but resized in certain parameters.</li>
</ul>

<p>I add files in <code>%source%</code> continuously, and I need to "synchronize" the 2 directories a couple of times in a week with a batch file.</p>

<p>I had thought of doing this:</p>

<ol>
<li>Compare <code>%source%</code> and <code>%target%</code> and find the new files</li>
<li>Copy the new files (each one with his subdirectory) in a <code>%temp_dir%</code>, or create the full path of the file/files and copy it/them into</li>
<li>Resize the files with irfanview</li>
<li>Move the resized jpg file from <code>%temp_dir%</code> to %target%</li>
</ol>

<p>What a good way to do this operation?</p>