A New Blind Image Watermarking of Handwritten Signatures using Low-Frequency Band DCT Coefficients

This paper deals with a new blind technique for robust image watermarking in the DCT domain. The technique is based on embedding watermark information in eight low-frequency band coefficients of the DCT sub-blocks. Single watermark has been embedded multi-times in the host image. 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.