Patents by Inventor Dimitris Anastassiou

Dimitris Anastassiou 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: 5193004
    Abstract: In accordance with the invention, a method, for coding multi-mode predictive interpolative coded fields of video, includes the steps of:(a) providing a current field of interlaced pixel data, and past and future fields of such data;(b) providing estimated pixel data at omitted line positions in the past and future fields of data to form enhanced fields of pixel data;(c) comparing a block of pixel data from the current field with corresponding blocks of data from such past and future fields to derive motion vector signals indicative of best matched blocks of data;(d) developing pixel error signals representing pixel by pixel errors based on utilization of best matched blocks in different modes for comparison with the block of pixel data from the current field and developing best mode signals indicative of which of such modes represents the least overall error; and(e) providing the best mode signals, motion vector signals, pixel error signals, and the future odd field of data for transmission for use by a decod
    Type: Grant
    Filed: December 3, 1990
    Date of Patent: March 9, 1993
    Assignee: The Trustees of Columbia University in the City of New York
    Inventors: Feng Ming Wang, Dimitris Anastassiou
  • Patent number: 5134480
    Abstract: Deinterlacing systems and methods useful with television and other interlaced data signals derive values for pixels on missing lines using best matching values for blocks of pixels through time-recursive comparison of current pixels block values with such values for prior frames of data and also with later frames. Noise propagation is attenuated by mixing of current interpolated pixel data and memory size efficiency is achieved by comparisons based on blocks of pixels, with the block size adjustable for data accuracy. Use of chrominance signal comparisons and reduced data rate coding techniques provide added capabilities to the deinterlacing systems and methods.
    Type: Grant
    Filed: August 31, 1990
    Date of Patent: July 28, 1992
    Assignees: The Trustees of Columbia University in the City of New York, American Telephone and Telegraph Company
    Inventors: Feng-Ming Wang, Dimitris Anastassiou, Arun N. Netravali
  • Patent number: 4926180
    Abstract: A 1-bit nonstandard A/D converter for converting a block u of N samples of a continuous time analog signal u(t) into N corresponding 1-bit binary values x, such that a distortion measure of the form d(u,x)=(Au-Bx).sup.T (Au-Bx) is minimized, is implemented with an N-input parallel sample-and-hold circuit and a neural network having N nonlinear amplifiers, where u and x are n-dimensional vectors, and A and B are N.times.N matrices. Minimization of the above distortion measure is equivalent to minimizing the quantity1/2x.sup.T B.sup.T Bx-u.sup.T A.sup.T Bx,which is achieved to at least a good approximation by the N-amplifier neural network. Accordingly, the conductances of the feedback connections among the amplifiers are defined by respective off-diagonal elements of the matrix -B.sup.T B. Additionally, each amplifier of the neural network is connected to receive the analog signal samples through respective conductances defined by the matrix B.sup.T.
    Type: Grant
    Filed: March 25, 1988
    Date of Patent: May 15, 1990
    Assignee: Trustees of Columbia University in the City of New York
    Inventor: Dimitris Anastassiou
  • Patent number: 4695884
    Abstract: Video images are corrected for shading effects by generating a histogram of picture element (pel) gray scale intensity values and calculating the median and the black and white extremes thereof. A range of permitted background gray scale values is empirically selected such as by calculating the distance between the median and the closest color extreme and setting the range as twice that distance centered at the median. A background image is then created by sampling the intensity values of the original image pels and using a look-up table to remap the image. In one embodiment, pel intensity values are compared with the median value and only corrections lying within the range are carried out. In another embodiment the original image pels are remapped from 8 bits to 5 bits with all values outside the permitted range set to that of the nearest color extreme.
    Type: Grant
    Filed: February 1, 1985
    Date of Patent: September 22, 1987
    Assignee: International Business Machines Corporation
    Inventors: Dimitris Anastassiou, William B. Pennebaker
  • Patent number: 4546385
    Abstract: Graphic images are generally considered to be those images comprised of text and/or drawings. Data compression of graphics images is desired whenever a fast image transmission speed is desired in a limited band width channel. It is also used for storage of a large number of images in a limited capacity storage system. A high compression ratio is achieved by thresholding the graphics image to a bilevel black-white image at one bit per pixel and then employing a second data compression on the black-white image. At low resolution, bilevel images have poor quality at edges and a quality improvement is needed. The data compression apparatus and method disclosed separates the graphics image into at least first and second bit planes identifies edge pixels from the first bit plane indicating a black/white change, locates the edge pixels and generates at least a single bit for each edge pixel indicating whether the edge pixel has a maximum intensity value such as black or white or an intermediate gray intensity value.
    Type: Grant
    Filed: June 30, 1983
    Date of Patent: October 8, 1985
    Assignee: International Business Machines Corporation
    Inventor: Dimitris Anastassiou
  • Patent number: 4504864
    Abstract: Apparatus and method are described for filtering noise from digital video images including means for determining first difference values between intensity values of current pel and one or more preceding pels, means for determining second difference values between intensity values of the current pel and one or more succeeding pels, means for limiting any of the first and second difference values that exceed a predetermined limit value, and means for generating a filtered value for the current pel by adding the intensity value of the pel to a scale summation of the limited first and second difference values.
    Type: Grant
    Filed: December 30, 1982
    Date of Patent: March 12, 1985
    Assignee: International Business Machines Corporation
    Inventors: Dimitris Anastassiou, William B. Pennebaker
  • Patent number: 4369463
    Abstract: The present invention relates to a method and apparatus for compacting gray-scale image data which maintains extremely good picture quality and can result in typical images in a compression ratio of 5 to 1 and even better if a final step of arithmetic coding is used. The method is a special application of adaptive differential pulse code modulation (DPCM) which utilizes a prediction of smoothness surrounding a current pel to determine variable length codes to convey the quantized error. Thus, a continuously adaptive variable length code is produced which may be accurately decoded without using any further marker (code indicator) bits. For each pel and "error bit" is generated to indicate to the decoder if the predicted quantization range is adequate. These eroror bits can be further significantly compressed.
    Type: Grant
    Filed: June 4, 1981
    Date of Patent: January 18, 1983
    Assignee: International Business Machines Corporation
    Inventors: Dimitris Anastassiou, Joan L. Mitchell