An Improvement Method for Data Embedding to Printing Images Based on DCT

This paper proposes an improvement method for a data embedding technique to printing images. This embedding technique is based on discrete cosine transform (DCT) and pseudo number (PN) sequences. In the conventional method, deformations, such as rotation and scaling have given a serious defect to the extraction rate. To solve this problem, a new data embedding position and the processing by the resolution of scanner itself are applied. The gain control method is also improved. From the comparison between the proposed and conventional methods, the improvement of the extraction rate in the proposed method is shown.