A Reversible Steganographic Algorithm for High Dynamic Range Images

This paper proposes a reversible data hiding algorithm for high dynamic range (HDR) images. To the best of our knowledge, our scheme is the first reversible approach, which can recover the cover HDR image without any distortion after the secret data being extracted. Our algorithm takes advantages of the differences of the neighboring pixels in the R, G and B channel to provide large embedding capacity. We exploit the difference of the neighboring pixels in the exponent channel E to embed dynamic ranges of the secret message, achieving that embedding adaptability. Experimental results show the our algorithm provides an average payload capacity for up to 0.13 similar to 0.63 bits per pixel (bpp). In addition, our algorithm produces a stego image with high visual quality. The normalized root mean squared error (NRMSE) is 0.05 similar to 0.83%, and the peak signal-to-noise ratio (PSNR) between the stego and cover HDR images after the tone mapping process is over 39 dB. Experimental results verify the feasibility of our algorithm in providing a reversible solution for steganography on high dynamic range images.