标题: 藉由逐张影像解码而得的渐进式分享
Progressive sharing with image-by-image decoding
作者: 张胜裕
Chang, Sheng-Yu
林志青
Lin, Ja-Chen
资讯科学与工程研究所
关键字: 影像分享;渐进式还原;image sharing;progressive sharing
公开日期: 2012
摘要: 我们提出三种将多组重要的影像渐进式还原的方法。在第一个方法的编码阶段,我们将每一张机密影像分成n等分并适当地组成重要性相等的分存,然后将这n个分存一对一的藏入n张掩护影像里。在第二个方法的编码阶段,编码的方式与第一个方法相似,然而在这个方法中,我们将掩护影像分组并给予适当的权重值,然后根据掩护影像组的权重值将分存藏入。在第三个方法的编码阶段,我们对机密影像采用传统的机密影像分享方法并渐进式地分享k把钥匙,然后将n个分存一对一的藏入n张掩护影像里,并从n张掩护影像里选择k张掩护影像将k个钥匙分存藏入。在第一个方法的还原阶段,如果我们收到分存的数量达到预设低(中或高)的阀值,那么我们就可以还原低(中或高)品质的机密影像。相同地,在第二(或第三)个方法的还原阶段,若将〝收到分存的数量〞换成〝总共收到的权重值〞(或〝收到钥匙分存的数量〞),也可以达到渐进式还原的效果。
We propose three kinds of sharing methods to progressively reveal several group of given important images in the recovery phase. In the encoding phase of Method 1, each secret image is divided into n parts, and the parts of all secret images are properly combined to get n shadows with equal importance. Then, we hide the n shadows in the n given cover images one by one. In the encoding phase of Method 2, the method is similar to the first method. However, we divide the n cover images into several groups, and equip each group with different weights. Then, according to the weight of each cover image group, we hide some of the n secret shadows in the cover group. In the encoding phase of the Method 3, we apply traditional (t, n) secret sharing to the n secret images, and then progressively share the k keys. Then, we hide the n shadows in the n cover images one by one, and then select k of the n cover images to hide in them the shadows of the k keys. In the recovery phase, if the number of received shadows reaches the pre-specified low (or middle or high) threshold of Method 1, then we can reconstruct a low (or middle or high) quality version of the secret images. Likewise, in Method 2 or 3, if we replace the words “the number of received shadows” by “the sum of received weights”, or “the number of received key shadows”, we also get progressive recovery effect.
URI: http://140.113.39.130/cdrfb3/record/nctu/#GT070056077
http://hdl.handle.net/11536/72011
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