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<article article-type="research-article">
  <front>
    <journal-meta>
      <journal-id journal-id-type="aggregator">72010604</journal-id>
      <journal-title>Electronic Imaging</journal-title>
      <issn pub-type="ppub">2470-1173</issn><issn pub-type="epub"></issn>
      <publisher>
        <publisher-name>Society for Imaging Science and Technology</publisher-name>
      </publisher>
    </journal-meta>
    <article-meta>
      <article-id pub-id-type="doi">10.2352/ISSN.2470-1173.2017.7.MWSF-323</article-id>
      <article-id pub-id-type="sici">2470-1173(20170129)2017:7L.36;1-</article-id>
      <article-id pub-id-type="publisher-id">s7.phd</article-id>
      <article-id pub-id-type="other">/ist/ei/2017/00002017/00000007/art00007</article-id>
      <article-categories>
        <subj-group>
          <subject>Articles</subject>
        </subj-group>
      </article-categories>
      <title-group>
        <article-title>How to recompress a JPEG crypto-compressed image?</article-title>
      </title-group>
      <contrib-group>
        <contrib>
          <name>
            <surname>Itier</surname>
            <given-names>Vincent</given-names>
          </name>
        </contrib>
        <contrib>
          <name>
            <surname>Puech</surname>
            <given-names>William</given-names>
          </name>
        </contrib>
      </contrib-group>
      <pub-date>
        <day>29</day>
        <month>01</month>
        <year>2017</year>
      </pub-date>
      <volume>2017</volume>
      <issue>7</issue>
      <fpage>36</fpage>
      <lpage>43</lpage>
      <permissions>
        <copyright-year>2017</copyright-year>
      </permissions>
      <abstract>
        <p>This paper presents a new method, of recompressing a JPEG crypto-compressed image. In this project, we propose a cryptocompression method which allows recompression without any information about the encryption key. The recompression can be executed on the JPEG bitstream directly by
 removing the last bit of the code representation of a non null DCT coefficient and adapting its Huffman code part. To be able to apply this approach, the quantization table is slightly modified to make up the modifications. This method is efficient to recompress a JPEG cryptocompressed image
 in terms of ratio compression. Moreover, since the encryption is fully reversible, the decryption of the recompressed image produces an image that has a similar visual quality compared to the original compressed image.</p>
      </abstract>
      <kwd-group>
        <kwd>ENCRYPTED DOMAIN</kwd>
        <kwd>RECOMPRESSION</kwd>
        <kwd>JPEG</kwd>
      </kwd-group>
    </article-meta>
  </front>
</article>
