Lijie Liu, 433208 Centennial Cir, Utica, NY 13502

2007019, Aug 23, 2007

Jan 4, 2007

11/649491

Trac Tran - Laurel MD, US
Lijie Liu - Baltimore MD, US
Pankai Topiwala - Clarksville MD, US

G06K 9/36

382250000

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.

2008017, Jul 24, 2008

Dec 31, 2007

11/968030

Trac D. Tran - Columbia MD, US
Lijie Liu - Skillman NJ, US
Pankaj N. Topiwala - Clarksville MD, US

G06K 9/36

382240

A reconstruction system for digital signals processed by the laplacian pyramid including a master lifting-based parameterization reconstruction scheme. The system also involves the design of low-complexity FIR linear-phase integer-coefficient filtering operators for lapacian pyramid decimation and interpolation stages that deliver a minimum mean-squared error reconstruction.