Abstract: A method and apparatus for performing compression and/or decompression is described. In one embodiment, the present invention comprises a system having a buffer, a wavelet transform unit, and a coder. The wavelet transform unit has an input coupled to the buffer to perform a wavelet transform on pixels stored therein and to generate coefficients at an output. The coder is coupled to the wavelet transform unit to code the transformed pixels received from the buffer.

Abstract: A method and apparatus for performing compression and/or decompression is described. In one embodiment, the present invention comprises a system having a buffer, a wavelet transform unit, and a coder. The wavelet transform unit has an input coupled to the buffer to perform a wavelet transform on pixels stored therein and to generate coefficients at an output. The coder is coupled to the wavelet transform unit to code the transformed pixels received from the buffer.

Abstract: A method and apparatus for performing compression and/or decompression is described. In one embodiment, the present invention comprises a system having a buffer, a wavelet transform unit, and a coder. The wavelet transform unit has an input coupled to the buffer to perform a wavelet transform on pixels stored therein and to generate coefficients at an output. The coder is coupled to the wavelet transform unit to code the transformed pixels received from the buffer.

Abstract: A method and apparatus for performing compression and/or decompression is described. In one embodiment, the present invention comprises a system having a buffer, a wavelet transform unit, and a coder. The wavelet transform unit has an input coupled to the buffer to perform a wavelet transform on pixels stored therein and to generate coefficients at an output. The coder is coupled to the wavelet transform unit to code the transformed pixels received from the buffer.

Abstract: A method and apparatus for performing compression and/or decompression is described. In one embodiment, the present invention comprises a system having a buffer, a wavelet transform unit, and a coder. The wavelet transform unit has an input coupled to the buffer to perform a wavelet transform on pixels stored therein and to generate coefficients at an output. The coder is coupled to the wavelet transform unit to code the transformed pixels received from the buffer.

Abstract: A method and apparatus for performing compression and/or decompression is described. In one embodiment, the present invention comprises a system having a buffer, a wavelet transform unit, and a coder. The wavelet transform unit has an input coupled to the buffer to perform a wavelet transform on pixels stored therein and to generate coefficients at an output. The coder is coupled to the wavelet transform unit to code the transformed pixels received from the buffer.

Abstract: A method and apparatus for performing compression and/or decompression is described. In one embodiment, the present invention comprises a system having a buffer, a wavelet transform unit, and a coder. The wavelet transform unit has an input coupled to the buffer to perform a wavelet transform on pixels stored therein and to generate coefficients at an output. The coder is coupled to the wavelet transform unit to code the transformed pixels received from the buffer.

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.

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.

Abstract: A method and apparatus for enhancing compressed images is described. In one embodiment, the method comprises characterizing quantization noise in reconstructed low pass coefficients generated in response to application of an inverse wavelet transform and removing the quantization noise from the reconstructed low pass coefficients constructed during decoding.

Abstract: A method and apparatus for performing block sequential processing is described. In one embodiment, the apparatus comprises a determine pass logic, selection logic, next coefficient logic and control. The determine pass logic has inputs coupled to receive significance state information for a region, a pass bit for each coefficient in a subset of the region, and a current pass indication. In response to these inputs, the determine pass logic generates pass indications to indicate a pass for each coefficient in the subset of the region. The selection logic has inputs coupled to signals output from the determine pass logic and the current pass indication and, in response to these inputs, generates output indications associated with one pass of either the significance propagation, refinement, and cleanup passes. The next coefficient logic is coupled to the selection logic and indicates the next coefficient in the current pass in response to the output indications from selection logic.

Abstract: A method and apparatus for performing compression and/or decompression is described. In one embodiment, the present invention comprises a system having a buffer, a wavelet transform unit, and a coder. The wavelet transform unit has an input coupled to the buffer to perform a wavelet transform on pixels stored therein and to generate coefficients at an output. The coder is coupled to the wavelet transform unit to code the transformed pixels received from the buffer.

Abstract: A method and apparatus for coding and decoding information is described. In one embodiment, the apparatus comprises a memory and decoding hardware. The memory stores run counts and/or skip counts and the decoding hardware decodes a run count and/or a skip count obtained from the memory during decoding.

Abstract: This provides for processing information by receiving downsampled pixel values, via, for instance, error diffusion, and upsampling each of the downsampled pixel values to construct a block of upsampled pixel values using statistics based on template pattern values of a predetermined number of downsampled pixel values or using replication.

Abstract: A method and apparatus for generating multiple selectable contexts is described. In one embodiment, the method comprises generating two contexts, one of the two contexts for when the current bit being decoded is a zero bit and the other of the two context for when the current bit being decoded is a one bit indicating that a coefficient has become significant, selecting one of the two context to use to decode a bit subsequent to the current bit, wherein selecting the one context is based on the current bit once decoded, and decoding the bit subsequent to the current bit using the one context.

Abstract: A method and apparatus for encoding and decoding data that includes 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 transform signals into data representing a losslessly compressed version of the input data. In one embodiment, the present invention decomposes the input data using reversible wavelet transforms.

Abstract: A system comprising a memory and wavelet processing logic is described. The memory is sized to include lines to store a band of an image and additional lines. The wavelet processing logic comprises a wavelet transform and access logic. The wavelet transform generates coefficients when applied to data in the memory. The access logic reads data from the memory into the line buffers to supply data stored in the memory to the wavelet transform and to store coefficients in the memory, such that after data stored at a first pair of lines is read from memory into the buffers of the access logic. The access logic reuses the first pair of lines to store coefficients generated by the wavelet transform that are associated with a second pair of lines different from the first pair of lines.

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.

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.

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.