Separable Reversible Data Hiding in Encrypted Images With High Capacity Based on Median-Edge Detector Prediction

In recent years, reversible data hiding technology in encrypted images has become an important topic for researchers. In addition, separable reversible data hiding technology in encrypted images also has been developed extensively because of its better practicability. In this paper, a new scheme of separable reversible data hiding in encrypted image is proposed based on the median-edge detector prediction. First, the predicted value of each pixel is calculated by using the median-edge detector predictor, and the difference between the original pixel and the predicted pixel is recorded according to the threshold parameter, and a label map is generated. Second, the original image is encrypted. Third, the differences and the secret bits are embedded into the pixels according to certain rules. After being compressed by using Run Length Coding and Huffman Coding, the label map is spliced to the bottom of the encrypted image. Finally, the stego-image is generated. When the receiver possesses the stego-image, which are the encrypted image that contain the hidden data, the desired image can be extracted or decrypted in accordance with a different key. The experimental results showed that our proposed scheme achieved better hiding capacity than the other schemes.