A New Blind Image Watermarking Technique for Dual Watermarks Using Low-Frequency Band DCT Coefficients

This paper deals with a new blind robust watermarking technique for embedding two watermarks into a host image. The technique is based on embedding watermark information in sixteen low-frequency band coefficients of the DCT sub-blocks. The Embedding process is based on changing the selected DCT-coefficients of the host image to odd or even values depending on the binary watermark´s bit value. The proposed blind watermarking embedding has shown to be strongly robust against several attacks.