An effective lossless dual-images based hiding method using block complexity and adopted thresholds

An effective lossless dual-images based hiding method using block complexity and adopted thresholds

Dual-images based hiding method is one kind of the hiding scheme which uses two duplicated images to conceal the secret message to generate the stego-images. Only a legal person who owns two stego-images can extract the correct message from the image. This kind of schemes been paid a lot of attention recently because it has better image quality and embedding capacity and realizes the concept of secret sharing. Lu et al. (2017) proposed a reversible dual-image based hiding scheme that used a block folding strategy to reduce the distortion between the cover image and the stego-image. They divided the secret message into two parts and encoded them into smaller digits to enhance the image quality of the stego-image. But their scheme needs an extra pixel to record the section numbers that limit the capacity of the secret message. This paper considers the complexity of the pixel to analysis how many bits can be embedded in the pixel to solve the problem. Furthermore, the proposed scheme applies an adaptive thresholds strategy to decide the thresholds for controlling the image quality. Experimental results show that the proposed scheme indeed improves the hiding performance.