Sun Microsystems, Inc.

Amazon Technologies, Inc.

Oracle America, Inc.

Russell Allen Brown

Hans Eberle

Nils Gura

Paul Hinks

Vipul Gupta

Paolo Maggi

Sheueling Chang-Shantz

Mark John Keller

Paolo Angelo Angelo Borelli

Systems and methods are described herein for repairing a block of pixels in image data that was encoding using a lossy type of compression. In one aspect, it may be determined that a first pixel block within a first frame of image data was encoded using lossy compression, where the first pixel block comprising a plurality of pixels. Next, it may be determined that the plurality of pixels in the first pixel block in a second frame of the image data are below a threshold difference as compared to the plurality of pixels within the first frame of the image data. Responsive to the determining, the first pixel block may be re-encoded in the second frame or a subsequent frame of the image data using lossless compression.

Lossy block repair

Systems and methods are described herein for implementing a hybrid codec to compress and decompress image data using both lossy and lossless compression. In one example encoding process, it may be determined whether a first block of pixels of a frame of image data contains an edge. A type of compression by which to encode the first block may be selected based on that determination. The first block may be compressed using the selected type of compression. At least one second value associated with the first block of pixels may be set to indicate at least oof the compressed value or the type of compression used to compress the first block.

Hybrid codec

Systems and methods are described herein for encoding and decoding image data. In one aspect, pixel data of a frame of image data may be obtained, where the pixel data contains multiple values. The pixels values may be encoded by determining a length of a first value, where the length is determined using a number of bits of the value for a first type of color value and a modified number of bits for a second type of color value. Both of the number of bits and the modified number of bits map to a first color type lookup table. A code length of the value may be determined using the first color type lookup table, wherein the first color type lookup table maps a plurality of lengths to a plurality of code lengths. A code may be generated for the value based on the value and the code length.

Adaptable golomb coding

Sequence alignment techniques are disclosed. In one embodiment, a sparse data structure is constructed that represents respective character positions of matching character sets in input sequences. This sparse data structure may take a variety of forms, including a 'tree of trees.' Once constructed, each match is linked to at most one other match using a local application of a predetermined algorithm (e.g., a Smith-Waterman-type scoring algorithm). The links between matches are analyzed and a possible alignment or set of alignments is produced.

Sequence matching algorithm

Modular multiplication of two elements X(t) and Y(t), over GF(2), where m is a field degree, may utilize field degree to determine, at least in part, the number of iterations. An extra shift operation may be employed when the number of iterations is reduced. Modular multiplication of two elements X(t) and Y(t), over GF(2), may include a shared reduction circuit utilized during multiplication and reduction. In addition, a modular multiplication of binary polynomials X(t) and Y(t), over GF(2), may utilize the Karatsuba algorithm, e.g., by recursively splitting up a multiplication into smaller operands determined according to the Karatsuba algorithm.

Modular multiplier

The present invention is a compression scheme for compressing audio and video data. An image is divided into blocks of pixels. In one test, if all of the pixels are approximately equal to the corresponding pixels in the previous block, then no data is sent for that block. In a second test, if all of the pixels in a block are approximately equal to a mean pixel value, then only one color value is transmitted. In a third test, if quantization of the pixels via companding results in an acceptable representation, the quantization is performed. The present invention uses quantization codes that are proportional to the logarithm of the magnitude of the range quantized, computation of a magnitude byte that permits rapid discovery of the number of bits used for quantization of a block, recursive packing and unpacking of quantized pixel data, and two-dimensional paths through the block.

Method and apparatus for compression and decompression of data

The present invention provides an entropy coding scheme using an adaptable prefix code. The prefix code is a binary representation of the algorithm used to compress and decompress the data. There are prefix zeros that represent the number of significant binary digits that follow the first one. According to one embodiment, this scheme works on both positive and negative integers and encodes lower order integers with a smaller length of codeword. In another embodiment, the zero integer is encoded as a special case with the shortest codeword. In yet another embodiment, the present scheme is preferred by data sets that are clustered about zero, such as image data sets that have been transformed via a wavelet transform or a discrete cosine transform.

Entropy coding using adaptable prefix codes

A method and apparatus for modeling the specular reflection of light from an object is disclosed. In accordance with one embodiment of the method, a portion of the object is modeled by one or more surfaces each having at least one vertex and an edge point corresponding to an edge. A sine value associated with a highlight angle is determined at each vertex and edge point, and a control value is determined at each vertex and edge point using the sine values. A specular input component at each point on the surface is determined using the control values. The specular input component is utilized to determine the specular light component at that particular point. Embodiments of apparatus implementing the method are also disclosed.

Method and apparatus for modeling specular reflection

The invention is a method and apparatus for clipping a function, such as a quadratic Bezier function defining a shading characteristic of an object being modeled. In accordance with the invention, a second or higher order function is clipped in &ldquo;linear&rdquo; fashion using barycentric coordinates. In accordance an embodiment of the invention, the method comprises the steps of determining a second or higher order function to be clipped, determining barycentric coordinates for at least one clipping point associated with a first order (i.e. linear) function associated with the second or higher order function and generating at least one clipping point associated with the second or higher order function using the barycentric coordinates. In one or more embodiments of the invention, the method includes the steps of using the barycentric coordinates to determine a reparameterized clipped function.

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Russell Allen Brown