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:
Mar. 27, 2007
Filed:
Nov. 05, 2003
Guo-zua Wu, Hsinchu, TW;
Yi-jung Wang, Hsinchu, TW;
Zu-wen Chao, Hsinchu, TW;
Chwan-chang Chen, Hsinchu, TW;
Guo-Zua Wu, Hsinchu, TW;
Yi-Jung Wang, Hsinchu, TW;
Zu-Wen Chao, Hsinchu, TW;
Chwan-Chang Chen, Hsinchu, TW;
Industrial Technology Research Institute, Chu-Tung, TW;
Abstract
A watermark embedding method based on DCT subband image characters is disclosed. An original image is converted into a frequency image using a discrete cosine transformation. The watermark information is then embedded into a specific embedding block in each macro-block of the frequency image. The method has the following advantages: (1) the image embedded by watermark is resistant from distortion and damages from compressions; (2) the watermark image can be extracted without employing the original image; and (3) the quality of the image embedded with the watermark image can remain intact.