1
Wenjun Zeng, Shaw Min Lei: Digital image scrambling for image coding systems. Sharp Laboratories of America, Marger Johnson & McCollom P C, January 7, 2003: US06505299 (133 worldwide citation)

Methods and apparatus for encryption and decryption of digital images are disclosed. A preferred embodiment operates on an image frame after that frame has undergone a space-frequency transform operation, such as a block DCT or wavelet transform, and before the frame is passed to a bitstream coder f ...


2
Shaw Min Lei, Ming Ting Sun, Kou Hu Tzou: Method and system for high order conditional entropy coding. Bell Communications Research, Leonard Charles Suchyta, March 29, 1994: US05298896 (95 worldwide citation)

Method and system for high order conditional entropy coding utilizing an incremental-tree-extension technique to design a conditional tree for the coding. For complexity reduction, code table reduction and non-uniform quantization of conditioning symbols or pixels is provided. A pattern matching tec ...


3
Shaw Min Lei: Compression and decompression of reference frames in a video decoder. Sharp Laboratories of America, Marger Johnson & McCollom P C, August 7, 2001: US06272180 (78 worldwide citation)

Methods and apparatus for compressing and decompressing reference frames in a video decoder present a low-complexity approach to conserving reference frame memory. At the same time, this approach provides PSNR and drift-reduction performance comparable to competing methods of relatively high-complex ...


4
Jin Li, Shaw Min Lei: Embedded image coder with rate-distortion optimization. Sharp Laboratories of America, Marger Johnson & McCollom, September 23, 2003: US06625321 (69 worldwide citation)

A rate-distortion optimized embedding (RDE) coder optimizes rate-distortion performance by coding information bits in the order of their R-D slope. RDE allocates the available coding bits first to the information bit with the steepest R-D slope, which indicates the largest distortion decrease per co ...


5
Ting Chung Chen, Shaw Min Lei, Ming Ting Sun: Continous presence video signal combiner. Bell Communications Research, Leonard Charles Suchyta, James W Falk, September 26, 1995: US05453780 (60 worldwide citation)

Four QCIF video input signals generated by participants in a multiparty video conference are combined in the coded domain to produce a merged CIF video output signal. When the CIF video output signal is transmitted back to each party's video terminal, a combined 2.times.2 image is displayed. A video ...


6
Jordi Ribas Corbera, Shaw Min Lei: Method and apparatus for optimizing quantizer values in an image encoder. Sharp Laboratories of America, Marger Johnson & McCollom, August 29, 2000: US06111991 (40 worldwide citation)

A quantizer controller identifies a target bit value equal to a total number of bits available for encoding a frame. A total amount of distortion in the frame is modeled according to predicted quantization values for each one of the blocks. The predicted quantization values are characterized accordi ...


7
Christopher Andrew Segall, Shaw min Lei: Method and apparatus for adaptive up-scaling for spatially scalable coding. Sharp Laboratories of America, Stolowitz Ford Cowger, January 25, 2011: US07876833 (31 worldwide citation)

Adaptive up-sample filtering is used to improve compression efficiency of spatially scalable coding systems by more effectively predicting the high-resolution (enhanced-layer) video (or image) from the low-resolution lower-layer video (or image). Different up-sample filters adaptive to local image p ...


8
Shaw Min Lei, Jin Li: Quad-tree embedded image compression and decompression method and apparatus. Sharp Laboratories of America, Marger Johnson & McCollom PC, March 12, 2002: US06356665 (29 worldwide citation)

A quad-tree embedded image coding technique is used in combination with a bit-plane encoding technique to provide an efficient and low complexity embedded image coding system. A simple quad-tree method identifies coefficients as significant, insignificant, or refinement at each successive quantizati ...


9
Jordi Ribas Corbera, Shaw Min Lei: Method and apparatus for a delay-adaptive rate control scheme for the frame layer. Sharp Laboratories of America, Marger Johnson & McCollom P C, April 2, 2002: US06366704 (25 worldwide citation)

A digital video encoder and method for its operation are disclosed. This encoder comprises a frame-layer rate controller that bases a rate-distortion-optimized target bit assignment T


10
Shaw Min Lei: System for avoiding start code emulation and long carry-over propagation. Sharp Laboratories of America, Marger Johnson et al, September 21, 1999: US05955977 (23 worldwide citation)

An encoding scheme controls long carry-over propagation while at the same time prevents start code emulation. An arithmetic encoder converts an input signal into an encoded bit stream that provides data compression of the original input signal. The encoding scheme identifies carry-overs from the enc ...