Method and Apparatus for Coding an Image Object of Arbitrary Shape
At the internet age, transmittal of video signal in digital form is very common. Among various video compression standards or processes established, Discrete cosine transform (DCT)- based block transform coding is one of the frequently used coding techniques for compression of still image. This method provides a compromise between energy packing ability and computation complexity. However, the existing shape-adaptive DCT (SA-DCT) method suffers from its non-regular structure and the non-existence of efficient implementation methods. Its hardware implementation requirement can make fabrication very costly.
This invention offers a new method and apparatus based on which the arbitrarily-shaped transform coding can be accomplished using the regular N-point DCT/IDCT. The existing fast algorithms and/or available chipsets could be thus utilized directly. The new method consistently provides several dB improvement over the LPE padding that is recommended in MPEG-4, at just a minimal increase in computation requirement at the encoder side only. It has low computational complexity, slightly better encoding performance, and no requirement for depadding process at the decoder side. Last but not least, this method can be easily integrated into any object-based video/image control system that supports arbitrarily-shaped coding functionally.
1. Provides consistently several dB improvement over the LPE padding
2. No quantization errors occurs at the highest frequencies positions
3. Much lower computation complexity
4. No de-padding process at the decoder side
5. Easy integration
6. Avoid redesigning of SA-DCT/SA-IDCT
- Object-based video/image coding systems found in multimedia applications/products
- Multimedia applications using MPEG-4
Patent Number: USRE42853E1
Application Number: US2006561770A
Inventor: Shen, Guobin | Zeng, Bing | Liou, Ming
Priority Date: 14 Aug 2000
Priority Number: USRE42853E1
Application Date: 20 Nov 2006
Publication Date: 18 Oct 2011
IPC Current: G06K000936 | G06K000934 | G06K000946 | H04N000726 | H04N000730 | H04N000750
US Class: 382243 | 382173 | 382232 | 382248 | 382250
Assignee Applicant: The Hong Kong University of Science & Technology
Title: Method and apparatus for coding an image object of arbitrary shape
Usefulness: Method and apparatus for coding an image object of arbitrary shape
Summary: For encoding image object.
Novelty: Image object encoding method involves transforming padded vector such that number of zero elements in predetermined transform locations of transformed vector is equal to number of padding elements
信息和通信技术/电信
图像处理
20 Nov 2006
US RE42853
TTC.PA.119
香港
