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:
Oct. 01, 2013
Filed:
Jan. 04, 2007
Trac D. Tran, Columbia, MD (US);
Pankaj N. Topiwala, Clarksville, MD (US);
Trac D. Tran, Columbia, MD (US);
Pankaj N. Topiwala, Clarksville, MD (US);
FastVDO, LLC, Columbia, MD (US);
Abstract
This invention relates to the design and implementation of a large family of fast, efficient, hardware-friendly fixed-point multiplierless inverse discrete cosine transforms (IDCT) and the corresponding forward transform counterparts. All of the proposed structures comprises of butterflies and dyadic-rational lifting steps that can be implemented using only shift-and-add operations. The approach also allows the computational scalability with different accuracy-versus-complexity trade-offs. Furthermore, the lifting construction allows a simple construction of the corresponding multiplierless forward DCT, providing bit-exact reconstruction if properly pairing with our proposed IDCT. With appropriately-chosen parameters, all of the disclosed structures can easily pass IEEE-1180 test. The high-accuracy algorithm of the present invention is over 100 times more accurate than IEEE-1180 specifications, leading to practically drifting-free reconstruction in popular MPEG-2 and MPEG-4 codecs even at the lowest quantization setting.