Research On Data Hiding For Binary Images

Data hiding embeds secret message into digital media such as text, images, video and audio. The intention of data hiding is marking, annotation, authentic distinction, copyright protection and communicating secret messages. It hides the communication process and both communication sides, so it is efficient. At present, Research mainly aims at color images and gray pictures, but less regards to binary images.This paper first introduces background of data hiding, such as its history, development, system model, category and application. Significance of data hiding for binary images is discussed, the technical difficulty is analyzed. Existing algorithms are summarized, strongpoint and weakness are analyzed. This paper takes binary image as main research object, data hiding algorithm for binary images is studied, and contribution lies in:First, some improvement has been made to an existing algorithm and a new method is proposed. Shuffling is applied to average the spatial distribution of pixels that can be flipped. Flippability of each pixel is computed, pixels are selected to flip based on its flippability. Capability and security of the algorithm is analyzed. Experiments and simulation prove that the algorithm causes little artifact to cover images.Second, a safe correspondence model named"writing on wet paper"is introduced and a data hiding method for binary images through wet paper coding is achieved. The sender has much freedom in choosing pixels to flip, and the secret message is transmitted with a shared key. The method is very safe, when extracting the message, the original cover image is not needed. Flow chat is designed and simulation is completed, key problem in the algorithm is analyzed and a solution is given, its weakness is pointed out at the same time.