Abstract: A method and apparatus for assigning codeblocks to coders operating in parallel is described. In one embodiment, the method comprises decomposing input data into a plurality of code-blocks, and assigning the plurality of code-blocks, on a code-block basis, to a plurality of MQ coders to code the plurality of code-blocks in parallel to balance, to the extent possible, an amount of coding to be performed by each of the plurality of MQ coders.

Abstract: A method and apparatus for block quantization for color halftoning is described. In one embodiment, the method comprises dividing an input image and an output image into blocks, wherein each block in the output image corresponds to one block in the input image. The method also includes dividing each block into subblocks if an edge exists in said each block, calculating a color average of each input block, and calculating a set of output colors for each block in the output image to match the color average of its corresponding block in the input image.

Abstract: A multimedia output device having embedded encryption functionality enables the outputting of content in an encrypted form. The multimedia output device receives the content to be encrypted, encrypts the content, and generates an electronic output of the encrypted content. The multimedia output device also generates an associated paper output that provides information about the decryption, such as a key, an identification of the electronic output of the encrypted content, and optionally a description of the contents of the content encrypted.

Abstract: A method and apparatus for reformatting electronic documents is disclosed. In one embodiment, the method comprises performing layout analysis on an electronic version of a document to locate text zones, assigning attributes for scale and importance to text zones in the electronic version of the document, and reformatting text in the electronic version of the document based on the attributes to create an image.

Abstract: A system is described. In one embodiment, the system comprises an image processing path and a print engine coupled to the image processing path. The image processing path processes an input image in a wavelet domain.

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 of generating an output image having a lower resolution than that of a source image is provided. A thinned image is generated by discarding outer pixels of the source image. In parallel with generation of the thinned image, an averaged image is generated, such that each pixel of the averaged image represents an average of a subset of pixels in the source image. A first output image is then generated by subsampling the pixels of the thinned image. A final output image is generated as a function of both the first output image and the averaged image.

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 eliminating flicker by quantizing values based on previous quantization is described. In one embodiment, the method comprises encoding a first coefficient value in a first frame of a motion sequence and subsequently setting a second coefficient in a second frame of the motion sequence and in the same position as the first coefficient to be within a predetermined closeness with the value of the first coefficient.

Abstract: 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.

Abstract: A wavelet transform filter is disclosed having a pair of line buffers, three pairs of high and low pass filter pairs, two pairs of cascaded delays, and first and second delays, where the second pair of cascade delays is coupled to the first output and has fourth and fifth delay outputs, and a third high pass filter element having inputs coupled to the first output and the fourth and fifth delay output, where the third high pass filter element generates a fifth output of coefficients in the HH subband. A second delay coupled to the fifth output and has a sixth delay output. A third low pass filter element has inputs coupled to the fifth output, the sixth delay output and the fifth delay output and generates a sixth output corresponding to the coefficients in the HL subband.

Abstract: A method and apparatus for editing an image while maintaining codestream size is described. In one embodiment, the method comprises determining a portion of a codestream to edit, decoding the portion of the codestream, performing an edit to the decoded portion of the codestream, recompressing edited data into coded data, and generating a replacement portion for the portion of the codestream by making size of the replacement portion equal to size of the portion of the codestream by adding padding to the replacement tile if the replacement tile is smaller than the portion of the codesteam or quantizing the replacement tile if the replacement tile is larger than the portion of the codestream.

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 selecting layers for quantization based on sideband information is described. In one embodiment, the method comprises receiving a codestream of compressed image data organized in multiple layers. Each of the layers comprises coded data that adds visual value to the image. The method also includes selecting one or more of the layers for quantization based on sideband information accompanying the codestream and decompressing non-quantized layers of the codestream.

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 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.

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 assigning codeblocks to coders operating in parallel is described. In one embodiment, the method comprises decomposing input data into a plurality of code-blocks, and assigning the plurality of code-blocks, on a code-block basis, to a plurality of MQ coders to code the plurality of code-blocks in parallel to balance, to the extent possible, an amount of coding to be performed by each of the plurality of MQ coders.

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.