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
Yuh Lin Chang, Wenjun Zeng: Method and apparatus for extracting indexing information from digital video data. Matsushita Electric Industrial, Harness Dickey & Pierce, October 27, 1998: US05828809 (106 worldwide citation)

A method and apparatus to automatically index the locations of specified events on a video tape. The events, for example, include touchdowns, fumbles and other football-related events. An index to the locations where these events occur are created by using both speech detection and video analysis al ...


3
Wenjun Zeng: Method for extracting multiresolution watermark images to determine rightful ownership. Sharp Laboratories of America, Robert D Varitz PC, April 16, 2002: US06373974 (59 worldwide citation)

A method for embedding and extracting visually imperceptible indicia in an image includes embedding a visually imperceptible indicia in an original image; testing a test image for an embedded visually imperceptible indica; and extracting the visually imperceptible indicia from the test image to dete ...


4
Sachin G Deshpande, Wenjun Zeng: Methods and systems for transmitting digital images. Sharp Laboratories of America, Krieger Intellectual Property, Scott C Krieger, April 17, 2007: US07206804 (54 worldwide citation)

Embodiments of the present invention comprise methods and systems for communicating a recipient-selected customization of a digital image using an index file. The index file associates a customization characteristic with the segments of the digital image required to construct a customized image that ...


5
Wenjun Zeng: Method of directional filtering for post-processing compressed video. Sharp Laboratories of America, Chernoff Vilhauer McClung & Stenzel, April 10, 2007: US07203234 (38 worldwide citation)

A method of post-processing decompressed images includes identification of the direction of an image edge in a pixel block of the image and filtering applied along the boundary of the block in a direction substantially parallel to the detected image edge. Pixels are selected for filtering on the bas ...


6
Wenjun Zeng, Shawmin Lei: Distortion-adaptive visual frequency weighting. Sharp Laboratories of America, Chernoff Vilhauer McClung & Stenzel, April 25, 2006: US07035473 (35 worldwide citation)

The ability of the visual system to detect contrast in an image is a function of the frequency of the contrasting pattern and the distortion of the image. The visual system is more sensitive to contrasting patterns of lower frequency. When the image is significantly distorted, the visual system is e ...


7
Wenjun Zeng, Shawmin Lei, Scott Daly: Image coding method using visual optimization. Sharp Laboratories of America, Marger Johnson & McCollom, December 2, 2003: US06658162 (33 worldwide citation)

A method for compressing and decompressing image information. An encoder receives initial image information and transforms said initial information using a linear transform to produce coefficients. These are then locally normalized using a neighborhood masking weighting factor, quantized and coded t ...


8
Yap Peng Tan, Wenjun Zeng, Shawmin Lei: Method for removing ringing artifacts from locations near dominant edges of an image reconstructed after compression. Sharp Laboratories of America, Marger Johnson & McCollom PC, March 16, 2004: US06707952 (31 worldwide citation)

A method to remove ringing artifacts from locations near dominant edges of an image reconstructed after compression. The image is decomposed into blocks small enough so that each would contain only one significant edge. A significant edge is tested as to whether it is a dominant edge of the image. I ...


9
Wenjun Zeng, Shawmin Lei: Digital watermarking in a perceptually uniform domain. Sharp Laboratories of America, Marger Johnson & McCollom, September 14, 2004: US06792129 (26 worldwide citation)

Methods and apparatus for watermarking a digital media object, and for detecting watermarks, are presented. The basic concept underlying the disclosed approach is watermarking/detection in a transform space that allows the same level of watermarking to be applied to all samples. For instance, in one ...


10
Sachin Deshpande, Wenjun Zeng: Error resilient digital video scrambling. Sharp Laboratories of America, Chernoff Vilhauer McClung & Stenzel, May 22, 2007: US07221761 (21 worldwide citation)

A method and an apparatus for error resilient, digital image scrambling are disclosed. Error resilience scrambling is produced by shuffling transform coefficients between arrays of coefficients arranged along an axis substantially orthogonal to the axis along which packetization of the coefficients ...