Abstract: A method, apparatus and article of manufacture for providing improved print quality regardless of media smoothness is disclosed. Information regarding the smoothness of media is ascertained and the information about the media smoothness is used in the generation of an output. A selectable halftone screen is used in the print device to provide different halftone screens for different media smoothness. The halftoning screens can be changed depending on the roughness of the media being used. Pre-defined halftone screens may be stored and selected for a range of media smoothness. The selection of the pre-defined halftones may be selected by the operator or may be selected automatically by the print device.

Abstract: Apparatus and method for flexible digital halftoning are provided in which novel pattern choices are allowed by not restricting the basic halftone patterns to grow sequentially. Rather, positions in a threshold array allow multiple transitions between on (i.e., printed with toner/ink) and off (not printed) as a function of the input value at the corresponding position. In one embodiment, multiple threshold matrices are employed and the output decision is a vote (e.g., exclusive OR) of the outputs of the individual threshold matrices. In another embodiment, each position contains an arbitrary bit vector to express the output for each input. This flexibility in growing basic halftone patterns allows the number of densities output to be larger than n+1 (where “n” is the number of dots within a basic halftone cell).

Abstract: A method, system, and data structure for the scaling down of data is provided. At least two blocks of transformed data samples representing at least two blocks of original data samples are received. One of at least two tables of constants is selected wherein each table of constants is capable of reducing the number of transformed data samples by a different factor. The constants taken from the selected table are applied to the at least two blocks of transformed data samples to produce one block of transformed data samples representing one block of final data samples. The data is processed one dimension at a time by multiplying the data in one dimension with selected constants taken from previously developed tables corresponding to the desired scale down factor. Scaling down by different factors in each dimension as well as scaling down in one dimension and scaling up in the other dimension may be achieved.

Abstract: A compiler for data processing outputs lower-level code for packing multiple signed data elements per register into a processor's registers using the rules set forth herein, and when executed, the code simultaneously operates on the elements in a register in a single cycle using the same operand. The elements can be independent of each other as defined by compiler directives, and the sizes of the elements in a register can differ from each other. Moreover, a relatively large element can be split across multiple registers. In an exemplary application, a data stream representing two images can be simultaneously processed using the same number of registers as have been required to process a single image. Or, a single image can be processed approaching N-times faster, where N is the number of elements per register. In any case, the present invention results in a significant increase in processing efficiency.

Abstract: Faster discrete cosine transforms that use scaled terms are disclosed. Prior to application of a transform, equations are arranged into collections. Each collection is scaled by dividing each of the discrete cosine transform constants in the collection by one of the discrete cosine transform constants from the collection. Each of the scaled discrete cosine transform constants are then represented with approximated sums of powers-of-2. During the execution phase the block of input data is obtained. A series of predetermined sums and shifts is performed on the data. The output results are saved.

Abstract: A method, system, and data structure for the scaling up of data is provided. A block of transformed data samples is received wherein the transformed data samples represent original data samples. One of at least two tables of constants is selected wherein each table of constants is capable of increasing the number of data samples by a different factor. The constants taken from the selected table are applied to the block of transformed data samples to produce at least two blocks of transformed data samples representing at least two blocks of original data samples. The data is processed one dimension at a time by multiplying the data in one dimension with selected constants taken from previously developed tables corresponding to the desired scale up factor. Scaling up by different factors in each dimension as well as scaling down in one dimension and scaling up in the other dimension may be achieved.

Abstract: Fast transforms that use early aborts and precision refinements are disclosed. When to perform a corrective action is detected based upon testing the incremental calculations of transform coefficients. Corrective action is then performed. The corrective action includes refining the incremental calculations to obtain additional precision and/or aborting the incremental calculations when the resulting numbers are sufficient.

Abstract: Provided is a method, system, program, and data structures for halftoning an input image comprised of at least two input color components. Each input color component provides input intensity values for the color component at pixel locations in the image. At least two halftoning screens are accessed. There is one screen for each color component and halftone output generated by at least one of the screens has a lines per inch (LPI) that is at least approximately twenty percent different than the LPI of halftone output generated by one other screen. The input image is separated into the separate color components. The accessed screen for each color component is applied to the input intensity values for the color component to produce output intensity values for the color component. The combined halftone outputs for all the color components form the output pixels.

Abstract: Apparatus and methods are provided for entering compressed data streams at selected reentry points to initiate decoding thereby allowing efficient manipulation of the compressed data and minimizing storage requirements. The reentry information preferably includes bit-level pointers and sufficient state information to initialize the decoder properly. This enables decoding without having to resume at independently decodable points, such as JPEG restart markers. For example, in the context of a JPEG image, in addition to the typical information available to the decoder that has been passed in earlier markers, the reentry information for a given MCU boundary may include: a bit-level pointer to the first block's DC Huffman code, the position of the output, and a DC predictor for each component of the MCU. This allows decompression to be performed in the appropriate order to accomplish various data manipulation operations, such as rotation, thus significantly reducing buffering requirements.

Abstract: Disclosed is a method, system, and program for halftoning data for an output device capable of rendering multiple intensities. Input values are received. For each received input value, the input value is used as an output value if the input value is a predetermined value. Otherwise, if the input value is not the predetermined value, then the input value is halftoned to produce an output value used to render one of multiple intensities. This allows the use of data intended for bi-level printers that may have already been halftoned.

Abstract: Provided is a method, system, program, and data structure for decompressing a compressed data stream whose decoded output comprises lines of two-dimensional data or other data whose decoding depends upon previously decoded data and where the desired output is only part of sequentially decoded output. Received are a compressed data set, at least one pointer to a location in the compressed data stream whose decoded output comprises a location on a line of data, and decoding information for each received pointer that enables decoding from a point within the compressed data stream addressed by the pointer. For each received pointer, the following steps are performed: (i) accessing the location in the compressed data stream addressed by the pointer in the reentry data set; and (ii) using the decoding information in the reentry data set to decode compressed data from the accessed location.

Abstract: A method, system, and data structure for the scaling of data is provided. An exemplary use of the disclosed embodiments involves the scaling up in size or the scaling down in size of computer images. n-dimensional transformed data representing some original n-dimensional real data is received. An m-dimensional inverse transform on the n-dimensional transformed data is performed to produce hybrid data, where 1?m<n. The hybrid data is scaled in p dimensions to produce scaled hybrid data representing a desired p-dimensional change in the n-dimensional real data where p?m. Finally, an m-dimensional forward transform is performed on the scaled hybrid data to produce n-dimensional scaled transformed data.

Abstract: A system and method for data processing includes packing multiple signed data elements per register into a processor's registers using the rules set forth herein, and simultaneously operating on the elements in a register in a single cycle using the same operand. The elements can be independent of each other, and the sizes of the elements in a register can differ from each other. Moreover, a relatively large element can be split across multiple registers. In an exemplary application, a data stream representing two images can be simultaneously processed using the same number of registers as have been required to process a single image. Or, a single image can be processed approaching N-times faster, where N is the number of elements per register. In any case, the present invention results in a significant increase in processing efficiency.

Abstract: A system and method for generating bounded-loss color transformation employed in the compression and decompression of multi-spectral images is provided. The bounded-loss color space transformations provide transformations from a first color space to a second color space and back to the first color space with bounded loss or error. The bounded loss or error allows for the near lossless compression and reconstruction of multi-spectral images transformed from a first color space to a second color space and ultimately back to the first color space.

Abstract: Fast transforms that use early aborts and precision refinements are disclosed. When to perform a corrective action is detected based upon testing the incremental calculations of transform coefficients. Corrective action is then performed. The corrective action includes refining the incremental calculations to obtain additional precision and/or aborting the incremental calculations when the resulting numbers are sufficient.

Abstract: Fast transforms that use multiple scaled terms is disclosed. The discrete transforms are split into sub-transforms that are independently calculated using multiple scaling terms on the transform constants. The effect of the scaling for the transform coefficients may optionally be handled by appropriately scaling the quantization values or any comparison values. Further, optimal representations of the scaled terms for binary arithmetic are found. The resulting calculations result in fast transform calculations, decreased software execution times and reduced hardware requirements for many linear transforms used in signal and image processing application, e.g., the DCT, DFT and DWT.

Abstract: We present a communication system which enables two or more parties to secretly communicate through an existing digital channel which has a primary function other than this secret communication. A first party receives a series of cover data sets, hides a certain amount of auxiliary data in the cover data sets, and then relays these cover data sets containing hidden data to a second party, aware of the hidden data. This second party may then extract the hidden data and either restore it to its original state (the state it was in before the first party received it) and send it along to its original intended destination, or may just simply extract the hidden auxiliary data. There exist a plethora of techniques for hiding auxiliary data in cover data, and any of these can be used for the hiding phase of the system. For example, in a JPEG cover data set, a Huffman table may be modified in such a way as to have no impact on the observable nature of the image, and several such schemes are presented here.

Abstract: A system and method for generating bounded-loss color transformations employed in the compression and decompression of multi-spectral images is provided. The bounded-loss color space transformations provide transformations from a first color space to a second color space and back to the first color space with bounded loss or error. The bounded loss or error allows for the near lossless compression and reconstruction of multi-spectral images transformed from a first color space to a second color space and ultimately back to the first color space.

Abstract: Provided are a method, system, and program for decoding compressed data. Compressed data is received and decoded. An error is detected while decoding a first location in the compressed data. A reentry data set is accessed having a pointer to a second location in the compressed data following the first location and decoding information that enables decoding to start from the second location. The second location in the compressed data is accessed and the decoding information in the accessed reentry data set is used to continue decoding the compressed data from the second location.

Abstract: Provided is a method, system, program, and data structures for decompressing a compressed data stream. The compressed data stream is decoded a first time to generate multiple reentry data sets. Each reentry data set includes a pointer to a location in the data stream and decoding information that enables decoding to start from the location addressed by the pointer. The compressed data stream is then decoded from the beginning to a point preceding a location addressed by a first reentry data set. For each generated reentry data set, the location in the compressed data stream addressed by the pointer in the reentry data set is accessed. The decoding information in the reentry data set is then used to decode compressed data from the accessed location to a point preceding the location addressed by the pointer in the next reentry data set. For concatenated bit planes, the original multi-bit pixel values are reassembled in buffers and then outputted.