Pegasus Imaging Corporation

Dimension, Inc.

Accusoft Corporation

Iterated Systems, Inc.

John H Elton

Stephen A Martucci

Lyman Porter Hurd

Carlos M Diaz-Perez

Michael F Barnsley

Alan D Sloan

Guy A Primiano

Charles S Moreman

William Douglas Withers

Dalong Li

Sebastian Steger

James R Bean

Image binarization methods and apparatus are described. A set of input image pixel values, e.g., a set of grayscale values corresponding to an input image, is processed to determine whether to recommend to use local binarization thresholds or a global binarization threshold. Edges including edge pixels are identified. A first histogram corresponding to edge pixel values and a second histogram corresponding to image pixel values are generated, subjected to one or more smoothing operations, and truncated, based on information derived from the edge histogram. Characteristics of the histograms including, e.g., minima, maxima, points of inflection, and hidden peaks, are determined, evaluated, and used to decide between local binarization thresholds and a global threshold. Based on the recommendation, a global threshold is used or local thresholds are used to process the set of input image pixel values and generate a corresponding set of bi-level values.

Methods and apparatus relating to image binarization

Methods and apparatus for generating a binarization threshold are described. A set of input image pixels is processed. Edges including edge pixels are identified. In various embodiments histograms of pixel values and edge pixel values are generated and jointly used in determining an appropriate binarization threshold. In some embodiments a first histogram of edge pixel values is used to determine an interval of pixel values of interest to limit the set of pixel values used for determining a binarization threshold statistically. In some embodiments a first histogram corresponding to edge pixel values and a second histogram corresponding to image pixel values are generated, subjected to one or more smoothing operations, and truncated, based on information derived from the edge histogram. Characteristics of the histograms including, e.g., minima, maxima, are determined, evaluated, and used to generate a best global threshold.

Method and apparatus for image binarization

Methods, systems, devices, and implementing technologies for up-scaling an original source video from a lower, first resolution to a desired output video having a higher, second resolution, using fractal zooming techniques to replace individual source pixels in each respective image frame of the original source video with a plurality of proposed replacement pixels in the vertical and horizontal dimensions having similar characteristics as the individual source pixel, reducing noise associated with each respective frame of the desired output video, re-sizing, as necessary, each respective replacement frame to the second resolution, and outputting each zoomed replacement frame to generate the desired output video, which is an up-scaled version of the original source video. The quality of the up-scaled output video is improved by using artifact filtering and linear smoothing techniques after the initial search and replace steps of the fractal zooming process.

Systems and methods for up-scaling video

A codec, systems, and methods for compressing video data includes selecting a current video frame of the video data, dividing the current video frame into multiple blocks, wherein each block has M&#xd7;N pixels, approximating the blocks of the current frame based on motion vectors associated with corresponding blocks from the previous frame, further refining the blocks of the current frame by determining optimal motion vectors for the blocks of the current frame based on the motion vectors provided (i) by the corresponding blocks from the previous frame, (ii) by the surrounding blocks in the current frame, and (iii) from successively smaller blocks within the current frame, wherein the optimal motion vectors for the blocks of the current frame are optimized to balance distortion and rate and wherein the optimal motion vectors are represented by codewords generated from Huffman tables.

Video codec systems and methods for determining optimal motion vectors based on rate and distortion considerations

Bi-level pixel values are generated from a set of input pixel values corresponding to an image. Various described methods and apparatus are well suited for applications with limited computational capability and/or limited available resources to be used for performing image processing. Corresponding to an individual input pixel being processed, a plurality of windows including the pixel are evaluated to determine statistics including a variance for each window. Based upon the determined variances, one of a plurality of binarization threshold generation functions is selected. A binarization threshold for the input pixel is determined using the selected binarization threshold generation function. A bi-level pixel value is generated based on a comparison of the input pixel value to the generated binarization threshold. In various embodiments, the binarization threshold determination functions use non-zero integer powers of one or more variances, and intentionally avoid performing a square root operation, thus limiting computational complexity.

Methods and apparatus for adaptive auto image binarization

Methods, systems, and devices for up-scaling a source input video from a lower, first resolution to a desired output video having a higher, second resolution, using fractal zooming techniques to replace each individual source pixel of each respective frame of the source input video with a multiple of proposed replacement pixels in the vertical and horizontal dimensions having similar characteristics as the individual source pixel, reducing noise associated with each respective frame of the desired output video, re-sizing, as necessary, each respective replacement frame to the second resolution, and outputting each zoomed replacement frame to generate the desired output video having a higher, second resolution, which is the up-scaled version of the source video. The fractal zooming techniques include identifying a plurality of candidate pixels from the source video and selecting a group of pixels from the candidate pixels that best matches the individual source pixel.

Methods and systems for up-scaling a standard definition (SD) video to high definition (HD) quality

A computerized system for up-scaling a source input video from a lower, first resolution to a desired output video having a higher, second resolution, using fractal zooming techniques to replace each individual source pixel of each respective frame of the source input video with a multiple of proposed replacement pixels in the vertical and horizontal dimensions having similar characteristics as the individual source pixel, converting each of the proposed replacement pixels into a desired color space for the desired output video, using low-pass filtering to reduce noise associated with each respective frame of the desired output video, down-sizing the output video to its desired resolution, and outputting each zoomed replacement frame to generate the desired output video.

A threshold determination method is selected from among a plurality of alternative global thresholding determination methods and, optionally, a local thresholding determination method based on characteristics of a histogram of grayscales values representing an image. When it is determined to use a global thresholding method, a single global binarization threshold value is determined using the selected global thresholding method. Various alternative global binarization threshold values include a predetermined constant, an average value of the two grayscale values, an Otsu method based threshold value, a Newton method based threshold value, and an Otsu method based threshold value based on a truncated version of the histogram. When it is determined to use local thresholding, a plurality of local binarization threshold values are determined corresponding to different non-overlapping blocks of the image. The determined binarization threshold(s) are applied to the gray scale pixel values to obtain a set of binary pixel values.

Methods and apparatus for auto image binarization

Video codec systems and methods for optimal motion vector with variable size blocks

Methods and apparatus for providing JPEG decoder functions are described. In particular, features and methods of the present invention are directed to an efficient way of implementing a non-common decoding path function used in an MQ-coder, such as the type used to decode JPEG-2000 images. The methods of the present invention are well suited for implementation on general purpose computers such as conventional personal computers (PCs) and can provide improved decoding speed, compared to known systems which use processing branches as part of a non-common decoding path function by reducing and, in some implementations completely avoiding, branches. Thus, branch prediction penalties associated with known decoding schemes are reduced or avoided leading, in many cases, to faster decoding rates when using a general purpose processor of a given speed or computational capability.

Methods and apparatus for performing MQ-decoding operations

Block-based image processing methods and apparatus that provide a reduction in block-transform image coding artifacts are described. In various embodiments, the invention is directly incorporated into a decoding process. In such embodiments, transform coefficients are modified in simple but particularly effective ways that reduce or eliminate many of the artifacts that were caused by the quantization of the transform coefficients during encoding and/or by independent block processing during encoding. In other embodiments, the invention is used on an image that has already been decoded. In such embodiments image data values are directly modified in a block-based fashion or a forward block transform is applied and then the methods of the invention for processing transform coefficient blocks are used, followed by an inverse transform operation to generate pixel values from the resulting processed transform coefficient blocks.

Methods and apparatus for improving quality of block-transform coded images

Improved methods and apparatus for implementing JPEG 2000 MQ encoding operations are described. The following features of the invention may be used alone or in combination to implement JPEG 2000's coefficient bit modeling 1) Lists of coefficients to be processed in one or more subsequent coding passes are generated as coefficients are processed. The list is allows processing in the subsequent coding pass to be limited to coefficients on the list; and 2) Generation, updating and use of a neighborhood descriptor value table that stores a neighborhood descriptor value for each coefficient of a block being processed. The neighborhood descriptor values provide information about the state of the coefficient and its adjacent neighbors. Neighborhood descriptor values are used to access a lookup table that provides one or more context values and/or sign value to be used in MQ encoding. The neighborhood descriptor value corresponding to a coefficient and the neighborhood descriptor values corresponding to coefficients adjacent the coefficient are updated when the coefficient becomes significant, e.g., a 1 is first encountered in the coefficient.

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Atlanta, GA, United States of America

John H Elton