A High Capacity and High Quality Data Hiding Algorithm for High Dynamic Range Images

This paper proposes a high capacity and quality steganographic algorithm for high dynamic range images. Given an input high dynamic range image with the RGBE format, our algorithm considers the luminance distribution characterized in the cover image and the intensity difference existed in the neighboring pixels. The algorithm estimates the overall amount of message that can be embedded in a single pixel. Then, different red, green, and blue channels are assigned to certain parts of the overall message based on the color sensitivity inherent from the human vision. Finally, we present a novel embedding technique to embed the payloads at each color channel. This allows our algorithm to be able to embed a great number of secret messages, yet producing the stego high dynamic range image with high visual quality. Experimental results show that, on average, the embedding capacity can achieve the magnitude of 11.6 similar to 13.5 bits per pixel when using our proposed algorithm. To the best of our knowledge, this capacity is the highest in the literature of steganography for high dynamic range images. Our algorithm has the following characteristics; namely, (1) it is appropriate to characteristics of high dynamic range images, (2) it offers extremely high capacity, (3) it provides high visual quality inherent to human vision, (4) it ensures the secure steganography, and (5) it belongs to the blind detection scheme.