Patents by Inventor James David Greenfield

James David Greenfield 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: 6999511
    Abstract: A digital video encoder is presented adapted for dynamically switching between sets of quantizer matrix tables without pausing encoding of a stream of video data. Two or more sets of quantizer matrix tables are held at the encoder's quantization unit and compressed store interface for dynamically switching between sets of quant matrix tables at a picture boundary of the sequence of video data, i.e., without stopping encoding of the sequence of video data. Further, while one set of matrix tables is being employed to quantize the stream of video data, the encoder can be updating or modifying another set of quantization matrix tables, again without stopping encoding of the sequence of video data.
    Type: Grant
    Filed: February 23, 1999
    Date of Patent: February 14, 2006
    Assignee: International Business Machines Corporation
    Inventors: Charles Edward Boice, James David Greenfield, John Mark Kaczmarczyk, Agnes Yee Ngai, Stephen Philip Pokrinchak
  • Patent number: 6198767
    Abstract: A method of encoding interlaced, full motion digital video image data. The digital video image data has two interlaced fields per frame with luminance and chrominance components, where the chrominance components are uncorrelated between adjacent fields. The method encompasses applying one field of chrominance information to both luminance fields of a frame. This encodes chrominance components at one quarter the spatial resolution of the luminance components.
    Type: Grant
    Filed: March 27, 1995
    Date of Patent: March 6, 2001
    Assignee: International Business Machines Corporation
    Inventors: James David Greenfield, Diane Marie Mauersberg, Agnes Yee Ngai
  • Patent number: 5760836
    Abstract: Method and apparatus for encoding a digital video image stream in an encoder. The encoding includes spatial compression of still images in the digital video image stream and temporal compression between the still images. The spatial compression is carried out by converting a time domain image of a macroblock to a frequency domain image of the macroblock, taking the discrete cosine transform of the frequency domain image, transforming the discrete cosine transformed macroblock image by a quantization factor, and run length encoding the quantized discrete cosine transformed macroblock image. The temporal compression is carried out by reconstructing the run length encoded, quantized, discrete cosine transformed image of the macroblock, searching for a best match macroblock, and constructing a motion vector between them. This forms a bitstream of runlength encoded, quantized, discrete cosine transformed macroblocks and of motion vectors.
    Type: Grant
    Filed: August 22, 1996
    Date of Patent: June 2, 1998
    Assignee: International Business Machines Corporation
    Inventors: James David Greenfield, Barbara Ann Hall, John Mark Kaczmarczyk, Agnes Yee Ngai