Secure and Robust Digital Watermarking on Grey Level Images

A good watermarking technique embeds information into a carrier image with virtually imperceptible modification of the image. The present paper found a novel fact that by inserting the watermark using Least Significant Bit (LSB), the grey value of the image pixel either remains same or increases or decreases to one. The present paper is focused on this issue and found that such ambiguity of grey level values by LSB method comes between successive even and odd grey level values only. The proposed method inserts hidden message on m x m windows, based on their grey level values and coordinate positions. The present approach allows high robustness, embedding capacity and enhanced security.