A lossless data hiding scheme in JPEG images with segment coding
This is an incremental improvement for secure data hiding in digital images.
The paper tackles the problem of embedding secret data into JPEG images without increasing file size, achieving a larger capacity than existing methods.
In this paper, we propose a lossless data hiding scheme in JPEG images. After quantified DCT transform, coefficients have characteristics that distribution in high frequencies is relatively sparse and absolute values are small. To improve encoding efficiency, we put forward an encoding algorithm that searches for a high frequency as terminate point and recode the coefficients above, so spare space is reserved to embed secret data and appended data with no file expansion. Receiver can obtain terminate point through data analysis, extract additional data and recover original JPEG images lossless. Experimental results show that the proposed method has a larger capacity than state-of-the-art works.