Secret Communication Based on Quantization Tables

Abstract: Because of the prevalence of internet, the information security issues have attracted much attention in recent years. Protecting privacy of exchanging information through media becomes the subject of many studies. The Quantization in JPEG is to encode the coefficients transformed by Discrete Cosine Transform (DCT) using a Quantization Table (QT) generated by a quality factor. Quantizing DCT coefficients by different QTs can be adopted to record the secret messages. Based on the variation of QTs, we propose two schemes in frequency domain to improve a data hiding method, in terms of correct extraction rate and image quality. Experimental results show that the proposed approaches can provide better correct extraction rate, higher image quality, and satisfactory embedding capacity.