Patents by Inventor Chwan-Chang Chen

Chwan-Chang Chen has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Watermark embedding method based on DCT subband image characters
    Patent number: 7197163
    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.
    Type: Grant
    Filed: November 5, 2003
    Date of Patent: March 27, 2007
    Assignee: Industrial Technology Research Institute
    Inventors: Guo-Zua Wu, Yi-Jung Wang, Zu-Wen Chao, Chwan-Chang Chen
  • Watermark embedding method based on DCT subband image characters
    Publication number: 20050018872
    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.
    Type: Application
    Filed: November 5, 2003
    Publication date: January 27, 2005
    Inventors: Guo-Zua Wu, Yi-Jung Wang, Zu-Wen Chao, Chwan-Chang Chen