| 講演抄録／キーワード |
| 講演名 |
2006-02-21 10:40
KL空間における復号閾値を鍵とした透かし法
○山本 武・角田 貢・小杉幸夫（東工大） |
| 抄録 |
（和） |
ネットワーク上の画像コンテンツの追跡や検証へ透かしの適用が期待される．前報では，マルチメディア通信による画像のデータ構造の乱れを利用した埋め込みによって，復号時に，埋め込み画像と透かしとの分離が困難となることについて報告した．このような性質を利用して，本稿では，透かしの暗号化による埋め込みを行い，復号において，閾値（鍵）を用いることでのみ透かしの抽出が可能となる方法を提案する．提案法では，暗号化透かしを適用した埋め込みによって，公開アルゴリズムにより抽出が行われた後，設定された閾値を用いることでのみ透かしの検出を行えるようになる．実験結果を示し，更に，鍵となる閾値の全探索による復号について考察する． |
| （英） |
A digital watermark is useful technology as a method to embed kind of key information for proof to digital contents. The digital watermark (KL watermark) for the image based on Karhunen Loeve transformation that we have proposed is an embedding method by application of the basis of an image. The method has confirmed that it has tolerance to JPEG compression and composite transformation. Moreover, it has a feature that an embedded watermark information can be taken out in the hand from received the embedding image. However, this feature is also the subject that the taken-out watermark will be used for another contents image. To such a subject, in the previous work , KL watermarking by low embedding intensity (dumping factor) was studied. Generally, by the digital watermarking, if a dumping factor becomes large, decoding accuracy will improve. Since there is such character, the embedding which enlarged the dumping factor in the range that can permit degradation of embedding quality of image is general approach. In the embedding by KL watermark such a tendency is also the same. In the previous study, in order to make it difficult to watermark divert, disorder of a data structure of embedding image is applied. Such disorder effect occurs in an embedding image, after an embedding image passes a multimedia communication system. Moreover, it was shown that separation with a cover image and a watermark becomes difficult in decoding by such embedding. In this paper, an image authentication based on KL watermark is proposed. First, by proposed method, encryption of a watermark is performed in embedding. In decoding, a watermark can be extracted only by performing decoding using a threshold value. Next, it is shown that decoding from the image by the proposed method is performed with the open algorithm of decoding, while this paper shows that decoding from the image embedded by conventional method is not performed. |
| キーワード |
（和） |
KL変換 / デジタル透かし / マルチメディア通信 / データ構造 / 公開アルゴリズム / / / |
| （英） |
Karhunen Loeve Transform / Watermarking / Multimedia Communication / Data Structure / Open Algorithm / / / |
| 文献情報 |
信学技報, vol. 105, pp. 23-28, 2006年2月. |
| 資料番号 |
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| 発行日 |
2006-02-14 (ITS, IE) |
| ISSN |
Print edition: ISSN 0913-5685 |
| PDFダウンロード |
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