Visual Cryptography for Image Processing: A Survey

The method in which the visual information is encrypted by the process of encryption and those encrypted images are decrypted via sight reading is said to be called as visual cryptography or it is a method to hide the picture or an image into non-identical number of shares (different shares) and they are distributed to different set of participants. There are two sets of participants namely qualified and unqualified. The qualified set will combine with the participants of non-qualified set in order to get the secret image. Or the qualified set of participants alone can get the secret image. This new system has two phases. In the initial phase, the secret image as an input generates or creates some meaningless shares (4 shares) based on an algorithm called GAS algorithm. In next phase, the cover images are added in each share. They are added using an algorithm called stamping algorithm and distributes the embedded pictures or images to the participants. In receiver end, the embedded images are processed to receive the covering images from the shares generated and by overlapping those shares, the secret images are retrieved. These shares are arranged in correct order. In proposed system the security problem and the pixel expansion problems are reduced. It also helps to increase in the number of shares. Finally the obtained secret image can be viewed in a high resolution. Soundarya B A | Sowmeya D | Yazhini G V"Visual Cryptography for Image Processing: A Survey" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-2 | Issue-1 , December 2017, URL: http://www.ijtsrd.com/papers/ijtsrd8206.pdf http://www.ijtsrd.com/engineering/information-technology/8206/visual-cryptography-for-image-processing-a-survey/soundarya-b-a