Patents by Inventor Christos Chrysafis

Christos Chrysafis has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 8373718
    Abstract: Embodiments of the claimed subject matter provide a system and process for enhancing the display of color in a graphical display. In one embodiment, a process is provided for color enhancement using a detection volume and a shift volume. In one embodiment, input from pixels, as color data, is compared to a detection volume. If the color data of an input is detected in the detection volume, the color data is modified to a corresponding position in the shift volume, the modification consisting of an enhancement to the original color.
    Type: Grant
    Filed: December 10, 2008
    Date of Patent: February 12, 2013
    Assignee: NVIDIA Corporation
    Inventors: Santanu Dutta, Christos Chrysafis
  • Publication number: 20100141671
    Abstract: Embodiments of the claimed subject matter provide a system and process for enhancing the display of color in a graphical display. In one embodiment, a process is provided for color enhancement using a detection volume and a shift volume. In one embodiment, input from pixels, as color data, is compared to a detection volume. If the color data of an input is detected in the detection volume, the color data is modified to a corresponding position in the shift volume, the modification consisting of an enhancement to the original color.
    Type: Application
    Filed: December 10, 2008
    Publication date: June 10, 2010
    Applicant: NVIDIA CORPORATION
    Inventors: Santanu Dutta, Christos Chrysafis
  • Publication number: 20070110151
    Abstract: A system and method are provided for encoding and compressing video data. A memory device is configured to store video data, and a corresponding memory controller controls the storage of video data in the memory device. A frame buffer compression module compresses frame data received from a video module to be stored in the memory device according to the memory controller and decompresses compressed frame data received from the memory device according to the memory controller for use by a video module. The frame buffer compression module includes a frame buffer compression encoder configured to encode and compress frame data received from a video module for storage in memory according to the memory controller. The frame buffer also includes a corresponding frame buffer compression decoder configured to decode and decompress frame data received from memory according to the memory controller for use by a video module.
    Type: Application
    Filed: November 14, 2005
    Publication date: May 17, 2007
    Applicant: ESS Technology, Inc.
    Inventors: Siu-Leong Yu, Nien-Tsu Wang, Kou-Hu Tzou, Christos Chrysafis, Xuhui Wu
  • Patent number: 7120196
    Abstract: To encode an unencoded block of a frame, a search window is defined within the frame. Each pixel disposed within the search window and disposed in the unencoded portion of the frame that is assigned a value. A difference is computed between the unencoded block and each possible block within the search window. The block having the smallest difference, together with this difference are used to encode the unencoded block.
    Type: Grant
    Filed: April 25, 2003
    Date of Patent: October 10, 2006
    Assignee: ESS Technology, Inc.
    Inventors: Siu-Leong Yu, Christos Chrysafis
  • Patent number: 6956973
    Abstract: A method of image encoding using subband decomposition followed by modified zerotree coding with a symbols for zero and significant zerotrees and isolated zeroes and isolated significant coefficients.
    Type: Grant
    Filed: September 30, 1998
    Date of Patent: October 18, 2005
    Assignee: Texas Instruments Incorporated
    Inventors: Jie Liang, Antonio Ortega, Youngjun Yoo, Christos Chrysafis
  • Publication number: 20040230425
    Abstract: To determine the number of bits to encode a current audio frame, in accordance with a running average of the common scale factors for all preceding audio frames, a common scale factor for the-current frame is computed. The current frame is encoded using the computed common scale factor if the same falls within a defined range, and the number of bits required to so encode the frame also falls within a calculated range. If, the number of bits required to so encode the frame falls outside the calculated range, an energy level associated with the current frame and a running average of the energies of all previous frames is computed, which in turn, are used to compute a target bit rate. Thereafter, a common scale factor which results in coding of the current frame using a number of bits close to the target bit rate is obtained.
    Type: Application
    Filed: May 16, 2003
    Publication date: November 18, 2004
    Applicant: Divio, Inc.
    Inventors: Siu-Leong Yu, Christos Chrysafis, Johnny Wang
  • Publication number: 20040230423
    Abstract: To select the encoding mode of an audio signal in a multi-channel system, a level of energy of the audio signal associated with each channel is determined, which in turn is used to compute a first value. Next, a second value based on a degree of correlation of the signals of each channel is determined. If the first value is smaller than the second value, the audio signal is encoded using a first encoding mode. Next, a third value defined by the energy levels and a fourth value defined by the correlation are computed. If the first value is greater than the second value, and the third value is smaller than the fourth value, the audio signal is encoded using a second encoding mode. Otherwise the audio signal is encoded using a third encoding mode.
    Type: Application
    Filed: May 16, 2003
    Publication date: November 18, 2004
    Applicant: Divio, Inc.
    Inventors: Christos Chrysafis, Siu-Leong Yu
  • Publication number: 20040230419
    Abstract: To encode an audio signal xn, N samples of the audio signal is taken during each period of the signal (i.e., n varies from 0 to N-1) and are stored in a memory, such as a DRAM. The indices of the input samples (i.e., coefficients) are divided into T groups such that M of these coefficients each associated with a different one of the indices of each of the T groups may be read from the DRAM in a burst read operation. The M coefficients read during each burst operation are stored in a second memory in a burst write operation. Thereafter, each T time-domain coefficients whose indices belong to the same group are used to compute a first set of complex numbers ƒs which are subsequently used to encode the signal. Because the read and write operations are carried out using burst modes, the number of memory accesses is reduced, thereby improving efficiency and reducing cost.
    Type: Application
    Filed: May 15, 2003
    Publication date: November 18, 2004
    Applicant: Divio, Inc.
    Inventors: Christos Chrysafis, Siu-Leong Yu, Charlie Cheng
  • Patent number: 6701020
    Abstract: A method, system and program product for compressing a compound image, comprising forming compound image data into a plurality of blocks; obtaining classifying data that designate one from a plurality of classes for each of a plurality of said blocks, based on predominate compression properties of the block; for each of a plurality of said blocks, obtaining transformed data therefor from either a lossy or a lossless transform selected based on the classifying data for the block; and forwarding that transformed data to one entropy encoder. In one embodiment, obtaining transformed data comprises obtaining transformed data from at least one of a lossy transform, a first lossless transform, or a second lossless transform, based on the classifying data for the transform.
    Type: Grant
    Filed: March 15, 2001
    Date of Patent: March 2, 2004
    Assignee: Hewlett-Packard Development Company, L.P.
    Inventors: Christos Chrysafis, Amir Said
  • Publication number: 20030202588
    Abstract: To encode an unencoded block of a frame, a search window is defined within the frame. Each pixel disposed within the search window and disposed in the unencoded portion of the frame that is assigned a value. A difference is computed between the unencoded block and each possible block within the search window. The block having the smallest difference, together with this difference are used to encode the unencoded block.
    Type: Application
    Filed: April 25, 2003
    Publication date: October 30, 2003
    Applicant: Divio, Inc.
    Inventors: Siu-Leong Yu, Christos Chrysafis
  • Patent number: 6546143
    Abstract: A subband decomposition of an image is performed by filtering the image in a progression of N line windows. In a first filter stage, vertical filters perform high and low pass filtering on each N line window. Then horizontal filtering is performed on the output of each vertical filter. The lowest subband provided by the filter stage is recursively decomposed by additional filter stages. Higher subbands of each filter stage are encoded and placed in an embedded bitstream. Block encoding can be performed in which a number of lines of each subband are coded as a plurality of blocks. The blocks of a subband are coded independently of each other. The block coding supports region-of-interest reconstruction.
    Type: Grant
    Filed: March 12, 1999
    Date of Patent: April 8, 2003
    Assignee: Hewlett-Packard Development Company
    Inventors: David S. Taubman, Christos Chrysafis, Erik Ordentlich
  • Publication number: 20020176632
    Abstract: A method, system and program product for compressing a compound image, comprising forming compound image data into a plurality of blocks; obtaining classifying data that designate one from a plurality of classes for each of a plurality of said blocks, based on predominate compression properties of the block; for each of a plurality of said blocks, obtaining transformed data therefor from either a lossy or a lossless transform selected based on the classifying data for the block; and forwarding that transformed data to one entropy encoder. In one embodiment, obtaining transformed data comprises obtaining transformed data from at least one of a lossy transform, a first lossless transform, or a second lossless transform, based on the classifying data for the transform.
    Type: Application
    Filed: March 15, 2001
    Publication date: November 28, 2002
    Inventors: Christos Chrysafis, Amir Said