摘要:
A method and apparatus for specifying quantization based upon the human visual system is described. In one embodiment, the method comprises specifying scalar quantization for application to one or more bit planes of luminance information in image data using a human visual system (HVS) weighting and quantizing bit planes of the luminance information in the image data based on specified scalar quantization.
摘要:
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.
摘要:
A method and apparatus for performing selective quantization by manipulation of refinement bits is described. In one embodiment, the method comprises performing a refinement coding pass to bit-planes of a code block to create refinement bits and setting refinement bits to the more probable symbol (MPS).
摘要:
A method and apparatus for outputting a codestream as multiple tile-part outputs with packets from tiles being output in each tile-part is described. In one embodiment, the method comprises coding of each tile of an input codestream, outputting packets of each tile as part of an output codestream as a first complete tile-part, storing remaining layers of each tile in a buffer, and outputting additional packets of each tile from the remaining layers as a second complete tile-part.
摘要:
A method and apparatus for performing scalar quantization with a power of two step size is described. In one embodiment, the method comprises receiving a sequence of image data to compress and specifying scalar quantization with a power of two step size using three bit values to apply to the sequence of image data.
摘要:
A method and apparatus for sending additional sideband information in a codestream is described. In one embodiment, the method comprises receiving a JPEG 2000 codestream of compressed image data having sideband information hidden therein and decompressing the codestream based on the sideband information.
摘要:
Compound document images are usually high resolution and high quality images that include color, graphics, and images in addition to text. The need for good compression is important for storage and transmission. Due to the large size, even compressed, it is often difficult to access document images quickly and efficiently for display on monitors. The nascent JPM file format enables the best compound document image compression in terms of rate-distortion. However, the access into a JPM file is limited by the access features of the coders used. JPEG 2000 is an image coding system that allows access to lower resolutions, progressive bit-rates, and regions of interest.
摘要:
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.
摘要:
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.
摘要:
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.