| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an image processor capable of protecting a part in an image by encrypting it. <P>SOLUTION: Multilayer data separated for every attribute by an attribute discrimination part 11 is generated based on a specified attribute and encryption processing is performed by an encryption part 12 about a layer of the specified attribute. As the technique of encryption, frequency conversion is performed to the layer to be encrypted, divided into a plurality by frequencies, the divided frequency components are synthesized with frequency components of other layers to perform frequency inverse transformation. Thus, the layer to be encrypted is embedded in other layers and encrypted in a frequency space. It is difficult for understanding the content of the encrypted layer even by watching the image. In decryption, the encrypted layer is restored by using a layer before synthesis as a key layer, extracting difference of frequency components between layers before and after the synthesis, respectively, synthesizing the difference and performing the frequency inverse transformation. <P>COPYRIGHT: (C)2008,JPO&INPIT |
