USA As Represented by Secretary of the Navy

Yuval Fisher

Everett William Jacobs

Roger D Boss

A method of encoding a digital image using adaptive partitioning in an iterated transformation image compression system is provided. A set of ranges R is initialized to include at least two uncovered ranges. A set of domains D is initialized to include only one member which is the entire image area. For each uncovered range in the set R: A transformation is generated for each domain in the set of domains. Each domain is transformed into corresponding transformed images to map onto each uncovered range in the set R. Each domain's transformation is optimized and is indicative of a domain's corresponding optimized transformation image for an associated uncovered range. Each optimized transformation image is compared with the associated uncovered range to provide error data as a function of the difference therebetween. The associated uncovered range is redefined as a covered range when the error data for the associated uncovered range is within predefined limits. The covered range is then added to the set of domains D. The associated uncovered range is partitioned into a plurality of non-overlapping image areas. Partitioning is based upon the features of the image bounded by the associated uncovered range and takes place when the error data for the associated uncovered range exceeds the predefined limits. Each of the non-overlapping image areas is added to the set R of uncovered ranges and the associated uncovered range is added to the set of domains D. The steps of generating, transforming, optimizing, comparing, redefining, partitioning and adding are repeated to select a set of covered ranges, domains and corresponding optimized transformations. The set of covered ranges form a non-overlapping tiling of the image and some iterate of the set of selected transformations is contractive. Information that identifies the set of covered ranges, domains and corresponding optimized transformations is stored compactly in an addressable memory.

Method of encoding a digital image using adaptive partitioning in an

A method is provided for encoding an image in an iterated transformation image compression system. The image, represented by an array of pixels, is partitioned into ranges and domains. A transformation is generated for each domain such that no transformation is constrained to be contractive. Each domain's transformation is optimized in terms of the intensity scaling and offset coefficients. A domain and corresponding optimized transformation is selected that minimizes transformation error data. These steps are repeated for a chosen plurality of the ranges that form a non-overlapping tiling of the image and such that the corresponding optimized transformations associated with the chosen plurality form an eventually contractive map. Information that identifies each of the chosen plurality of the ranges and the selected domains and corresponding optimized transformations is then stored in an addressable memory as an encoding of the image.

Growing community of inventors

La Jolla, CA, United States of America

Yuval Fisher