Patent ID: 7006659
Filing Date: 2006-02-28
Classification: G06T,H04N

Abstract:
1. A method for embedding and extracting a spatial domain blind watermark using a sample expansion in a watermarking method for embedding a watermark information for protecting a copyright of a digital image in the digital image, the method comprising the steps of: creating a pseudo binary random number having a constant size in row and column directions and setting a sample-pair according to the pseudo binary random number; expanding the pseudo binary random number by a constant size in the row and column directions according to a set sample expansion coefficient; tiling the expanded sample-pair blocks at a constant number; creating a watermark bit corresponding to the each tile and converting a polarity of the each tile according to the watermark bit information; multiplying an average pixel value every tile with a watermark embedding intensity to compute a watermark value to be embedded; and embedding the watermark in a pixel within the tile according to the computed watermark value and collecting a partial image in which the watermark is embedded, every tile to acquire a finally watermarked image.