Xerox Corporation

Patrick A Fleckenstein

Dennis Lee Venable

Ricardo L De Queiroz

William A Fuss

James E Bollman

A method for filtering digital data using techniques normally utilized for data compression prior to transmission or storage. These techniques include codebooks and codewords as found with vector quantization and the approach of using look-up tables as found in hierarchical vector quantization. The method described herein achieves exemplary filtering results by using the above techniques in an overlapping fashion rather than being directed in the usual manner so as to achieve data compression. The codewords thus generated by this series of overlapping look-up stages are approximations of the input data neighborhoods. The method achieves filtering by the processing and applying of a mapping function to these output codewords, thereby associating filter output values to the input digital data.

HVQ-based filtering method

A period-based method for converting digital image data for a plurality of pixels from a first bit depth to a second bit depth includes receiving an input scanline of an arbitrary length comprising digital image data for a plurality of input image pixels. Each of the input image pixels is defined at the first bit depth. The input scanline is divided into a plurality of periods each comprising digital image data for a select number of input image pixels. The period is selected so that the image data for the select number of input image pixels exactly comprises m bytes when defined at the first bit depth and exactly comprises n bytes when defined at the second bit depth, wherein m and n are different integers. For each of the periods in succession, the image data for each of the select number of input image pixels is converted from the first bit depth to the second bit depth. A code generator generates hard-coded conversion operating instructions and a look-up table for specified bit conversion operations and generic conversion operating instructions for all other bit conversion operations.

Period-based bit conversion method and apparatus for digital image processing

This invention provides a device and method for processing data with a data processing string having push type and pull type tasks. Push tasks processes data and pushes the output of the process to downstream push tasks based on link paths. On the other hand, pull tasks sends data requests via upstream links to upstream pull tasks to acquire data for processing. Data processing strings are usually configured with either push tasks and/or pull tasks to maintain consistency in the direction of links. The preferred embodiments of this invention provides a method and apparatus for inserting push tasks in a string of pull tasks and inserting pull tasks in a string of push tasks. The inserted push and pull tasks are enhanced with forward and backward message links and interface tasks are provided to interface between the inserted pull or push tasks in the strings of push or pull tasks, respectively.

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Rochester, NY, United States of America

Patrick A Fleckenstein