Patents by Inventor Ahmad Zandi

Ahmad Zandi 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).

  • Publication number: 20030118241
    Abstract: A compression and decompression system in which a reversible wavelet filter are used to generates coefficients from input data, such as image data. The reversible wavelet filter is an efficient transform implemented with integer arithmetic that has exact reconstruction. The present invention uses the reversible wavelet filter in a lossless system (or lossy system) in which an embedded codestream is generated from the coefficients produced by the filter. An entropy coder performs entropy coding on the embedded codestream to produce the compressed data stream.
    Type: Application
    Filed: August 22, 2002
    Publication date: June 26, 2003
    Applicant: Ricoh Company, Ltd.
    Inventors: Ahmad Zandi, Edward L. Schwartz, Michael J. Gormish, Martin Boliek
  • Patent number: 6466699
    Abstract: A reversible Discrete Cosine Transform (DCT) is described. The reversible DCT may be part of a compressor in a system. The system may include a decompressor with a reversible inverse DCT for lossless decompression or a legacy decompressor with an inverse DCT for lossy decompression.
    Type: Grant
    Filed: August 20, 1999
    Date of Patent: October 15, 2002
    Assignees: Ricoh Company, LTD, Ricoh Corporation
    Inventors: Edward L. Schwartz, Ahmad Zandi
  • Publication number: 20020048405
    Abstract: A method and apparatus for encoding and decoding data is described. The present invention includes a method and apparatus for generating transformed signals in response to input data. In one embodiment, the transformed signals are generated using a reversible wavelet transform. The present invention also includes a method and apparatus for compressing the transformed signals into data representing a losslessly compressed version of the input data. In one embodiment, the present invention decomposes the input data using a non-minimal length reversible filter. The decomposition may be performed using multiple one-dimension filters.
    Type: Application
    Filed: September 30, 1997
    Publication date: April 25, 2002
    Inventors: AHMAD ZANDI, JAMES D. ALLEN, EDWARD L. SCHWARTZ, MARTIN BOLIEK
  • Publication number: 20020009235
    Abstract: A reversible Discrete Cosine Transform (DCT) is described. The reversible DCT may be part of a compressor in a system. The system may include a decompressor with a reversible inverse DCT for lossless decompression or a legacy decompressor with an inverse DCT for lossy decompression.
    Type: Application
    Filed: August 20, 1999
    Publication date: January 24, 2002
    Inventors: EDWARD L. SCHWARTZ, AHMAD ZANDI
  • Publication number: 20010031096
    Abstract: A reversible Discrete Cosine Transform (DCT) is described. The reversible DCT may be part of a compressor in a system. The system may include a decompressor with a reversible inverse DCT for lossless decompression or a legacy decompressor with an inverse DCT for lossy decompression.
    Type: Application
    Filed: February 12, 2001
    Publication date: October 18, 2001
    Inventors: Edward L. Schwartz, Ahmad Zandi
  • Patent number: 6222941
    Abstract: A method and apparatus for encoding and decoding data is described. The present invention includes a method and apparatus for generating transformed signals in response to input data. In one embodiment, the transformed signals are generated using a reversible wavelet transform. The present invention also includes a method and apparatus for compressing the transformed signals into data representing a losslessly compressed version of the input data. In one embodiment, the present invention decomposes the input data using a non-minimal length reversible filter. The decomposition may be performed using multiple one-dimension filters.
    Type: Grant
    Filed: August 9, 1996
    Date of Patent: April 24, 2001
    Assignees: Ricoh Co., Ltd., Ricoh Corporation
    Inventors: Ahmad Zandi, James D. Allen, Edward L. Schwartz, Martin Boliek
  • Patent number: 6219458
    Abstract: Recently, a number of reversible wavelet transforms have been identified which allow for exact reconstruction in integer arithmetic. Different transforms vary in how rounding is performed. The present invention provides a transform, which is linear except for the rounding with non-linear operations in order to create a reversible implementation. Also, the present invention also provides transforms which are decomposed into all FIR parts.
    Type: Grant
    Filed: July 30, 1999
    Date of Patent: April 17, 2001
    Assignees: Ricoh Co., Ltd., Ricoh Corporation
    Inventors: Ahmad Zandi, Edward L. Schwartz
  • Patent number: 6216145
    Abstract: Recently, a number of reversible wavelet transforms have been identified which allow for exact reconstruction in integer arithmetic. Different transforms vary in how rounding is performed. The present invention provides a transform, which is linear except for the rounding with non-linear operations in order to create a reversible implementation. Also, the present invention also provides transforms which are decomposed into all FIR parts.
    Type: Grant
    Filed: July 30, 1999
    Date of Patent: April 10, 2001
    Assignees: Ricoh Co., Ltd., Ricoh Corporation
    Inventors: Ahmad Zandi, Edward L. Schwartz
  • Patent number: 6195466
    Abstract: A reversible Discrete Cosine Transform (DCT) is described. The reversible DCT may be part of a compressor in a system. The system may include a decompressor with a reversible inverse DCT for lossless decompression or a legacy decompressor with an inverse DCT for lossy decompression.
    Type: Grant
    Filed: August 20, 1999
    Date of Patent: February 27, 2001
    Assignees: Ricoh Company, Ltd., Ricoh Corporation
    Inventors: Edward L. Schwartz, Ahmad Zandi
  • Patent number: 6195465
    Abstract: A compression and decompression system in which a reversible wavelet filter are used to generates coefficients from input data, such as image data. The reversible wavelet filter is an efficient transform implemented with integer arithmetic that has exact reconstruction. The present invention uses the reversible wavelet filter in a lossless system (or lossy system) in which an embedded codestream is generated from the coefficients produced by the filter. An entropy coder performs entropy coding on the embedded codestream to produce the compressed data stream.
    Type: Grant
    Filed: June 30, 1995
    Date of Patent: February 27, 2001
    Assignees: Ricoh Company, Ltd., Ricoh Corporation
    Inventors: Ahmad Zandi, Edward L. Schwartz, Michael J. Gormish, Martin Boliek
  • Patent number: 6058215
    Abstract: A reversible Discrete Cosine Transform (DCT) is described. The reversible DCT may be part of a compressor in a system. The system may include a decompressor with a reversible inverse DCT for lossless decompression or a legacy decompressor with an inverse DCT for lossy decompression.
    Type: Grant
    Filed: April 30, 1997
    Date of Patent: May 2, 2000
    Assignees: Ricoh Company, LTD., Ricoh Corporation
    Inventors: Edward L. Schwartz, Ahmad Zandi
  • Patent number: 6008745
    Abstract: One embodiment of the present invention provides a method and an apparatus for decoding a variable length code using lookup tables. This embodiment improves lookup performing by allowing multiple symbols to be retrieved in a single lookup, and allowing lookups into different tables to proceed in parallel. Another embodiment of the present invention provides for multiple secondary lookup tables to be selected based upon a prefix value decoded by a primary lookup table. Thus, one embodiment of the present invention can be characterized as an apparatus for decoding a variable length code. This apparatus includes an input from an encoded bitstream, the input including a first set of bits and a second set of bits. This apparatus also includes a first table indexed by the first set of bits, which includes entries containing decoded symbols corresponding to variable length codewords in the first set of bits.
    Type: Grant
    Filed: February 17, 1998
    Date of Patent: December 28, 1999
    Assignee: Sun Microsystems, Inc.
    Inventors: Ahmad Zandi, Krishna K. Noru
  • Patent number: 6006226
    Abstract: A set of image feature extraction techniques to locate and group documents based upon appearance in a database management system. The system automatically determines visual characteristics of document images and collects documents together according to the relative similarity of their document images. The system is operable on both binary and grayscale images.
    Type: Grant
    Filed: September 24, 1997
    Date of Patent: December 21, 1999
    Assignees: Ricoh Company Limited, Ricoh Corporation
    Inventors: John F. Cullen, Alex Keith, Ahmad Zandi
  • Patent number: 5999656
    Abstract: Recently, a number of reversible wavelet transforms have been identified which allow for exact reconstruction in integer arithmetic. Different transforms vary in how rounding is performed. The present invention provides a transform, which is linear except for the rounding with non-linear operations in order to create a reversible implementation. Also, the present invention also provides transforms which are decomposed into all finite inpulse response parts.
    Type: Grant
    Filed: January 17, 1997
    Date of Patent: December 7, 1999
    Assignees: Ricoh Co., Ltd., Ricoh Corporation
    Inventors: Ahmad Zandi, Edward L. Schwartz
  • Patent number: 5966465
    Abstract: A compression and decompression system in which a reversible wavelet filter are used to generates coefficients from input data, such as image data. The reversible wavelet filter is an efficient transform implemented with integer arithmetic that has exact reconstruction. The present invention uses the reversible wavelet filter in a lossless system (or lossy system) in which an embedded codestream is generated from the coefficients produced by the filter. An entropy coder performs entropy coding on the embedded codestream to produce the compressed data stream.
    Type: Grant
    Filed: May 3, 1996
    Date of Patent: October 12, 1999
    Assignees: Ricoh Corporation, Ricoh Company, Ltd.
    Inventors: Alexander F. Keith, Edward L. Schwartz, Ahmad Zandi, Martin Boliek, Michael J. Gormish
  • Patent number: 5881176
    Abstract: A compression and decompression system in which a reversible wavelet filter are used to generates coefficients from input data, such as image data. The reversible wavelet filter is an efficient transform implemented with integer arithmetic that has exact reconstruction. The present invention uses the reversible wavelet filter in a lossless system (or lossy system) in which an embedded codestream is generated from the coefficients produced by the filter. An entropy coder performs entropy coding on the embedded codestream to produce the compressed data stream.
    Type: Grant
    Filed: May 3, 1996
    Date of Patent: March 9, 1999
    Assignees: Ricoh Corporation, Ricoh Company, LTD.
    Inventors: Alexander F. Keith, Edward L. Schwartz, Ahmad Zandi, Martin Boliek, Michael J. Gormish
  • Patent number: 5867602
    Abstract: A compression and decompression system in which a reversible wavelet filter are used to generates coefficients from input data such as image data. The reversible wavelet filter is an efficient transform implemented with integer arithmetic that has exact reconstruction. The present invention uses the reversible wavelet filter in a lossless system (or lossy system) in which an embedded codestream is generated from the coefficients produced by the filter. An entropy coder performs entropy coding on the embedded codestream to produce the compressed data stream.
    Type: Grant
    Filed: June 30, 1995
    Date of Patent: February 2, 1999
    Assignees: Ricoh Corporation, Ricoh Company Ltd.
    Inventors: Ahmad Zandi, Edward L. Schwartz, Michael J. Gormish, Martin Boliek
  • Patent number: 5815097
    Abstract: The present invention provides a method and apparatus for compressing and/or decompressing data. In one embodiment, a system comprises a one-pass spatially embedded compressor and a limited bandwidth channel. The compressor comprises image data into compressed image data in one-pass. The compressor comprises an encoder and a coded data manager.
    Type: Grant
    Filed: May 23, 1996
    Date of Patent: September 29, 1998
    Assignees: Ricoh Co. Ltd., Ricoh Corporation
    Inventors: Edward L. Schwartz, Ahmad Zandi, Tibor Boros
  • Patent number: 5748786
    Abstract: A method and apparatus for encoding and decoding data is described. The present invention includes a method and apparatus for generating transformed signals in response to input data. In one embodiment, the transformed signals are generated using a reversible wavelet transform. The present invention also includes a method and apparatus for compressing the transformed signals into data representing a losslessly compressed version of the input data. In one embodiment, the present invention decomposes the input data using a non-minimal length reversible filter. The decomposition may be performed using multiple one-dimension filters.
    Type: Grant
    Filed: September 21, 1994
    Date of Patent: May 5, 1998
    Assignees: Ricoh Company, Ltd., Ricoh Corporation
    Inventors: Ahmad Zandi, James D. Allen, Edward L. Schwartz, Martin Boliek
  • Patent number: 5731988
    Abstract: A method and apparatus for performing color conversion on image data provided as a plurality of vectors representing a datum of the image. The present invention provides a forward transform that performs reversible color conversion on the plurality of vectors, such that the transform is reversible in integer arithmetic with predictable precision.
    Type: Grant
    Filed: May 8, 1995
    Date of Patent: March 24, 1998
    Assignees: Richo Company, Ltd., Richo Corporation
    Inventors: Ahmad Zandi, Edward L. Schwartz