The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 29, 2003
Filed:
Apr. 20, 1999
Xiang-Gen Xia, Newark, DE (US);
Charles Boncelet, Jr., Newark, DE (US);
Gonzalo R. Arce, Wilmington, DE (US);
University of Delaware, Newark, DE (US);
Abstract
The present invention relates to multiresolution watermarking methods for digital images which are based on a discrete wavelet transform (DWT). Pseudo-random codes are added to the large coefficients located at the high and middle frequency bands of the DWT of a digital image. A peak is detected to signify a signature of the watermark. The methods taught herein are more robust then conventional methods for common image distortions, such as the wavelet transform based image compression, additive noise, image halftoning, and image resealing. Moreover, the method is hierarchal. The computational load needed to detect the watermark depends on the noise level in an image. The multiresolution and hierarchial watermarking method taught by the present invention results in lower computational loads, on average, while providing a high quality watermark which is utilizable with modern image/video compression standards.