Abstract: An improved binary tree and decoder are disclosed wherein all the codewords are moved to one side of a binary tree. A compressed bit stream is fed to a decoder. The decoder uses a parser, an address generator, and the binary tree to determine the codewords contained in the compressed bit stream. The decoder examines the variable length encoded bits and compares them with the binary tree at each level to determine if the codeword is complete. The parser detects the end of the codeword and generates an offset for the address generator. The address generator uses the binary tree and offset to generate a block address for each unique codeword. The block address is then used to output uncompressed data from a pattern look up table.

Abstract: The present invention is directed to systems and methods for compressing image data while at the same time, the speed of compression, the compression ratio (that is, reduced memory requirements) and the perceptibility of the decompressed image, even when the image data is compressed without segregation into its scanned and non-scanned components. Exemplary embodiments achieve such improved perceptibility regardless of whether the images are monochrome (having varying grey scale values) or color. In addition, improved perceptibility is realized in a manner which permits image data including scanned and/or unscanned images to be compressed in real-time.

Abstract: A system and method for efficient image encoding begins by loading a series of image blocks. A current block is compared with an immediately preceding image block for coincidence, and coded as matching or nonmatching based on the comparison results. The system further compares the nonmatching image blocks with a stack containing a list of the most recently encountered image blocks. Image blocks matching an entry in the list are coded by reference to the appropriate entry in the list. In the event a match is still unavailing, the system determines if the image blocks may be categorized as a bilevel text block, a bilevel image block, a block containing only one gray pixel, or a block containing multiple gray pixels. Each nonmatching block is classified according this classification criteria.

Abstract: A method and structure for a printing system for a laser printer is provided including a data storage area containing a plurality of separate waveform signals. A controller selects a particular waveform signal to modulate the signal input to the system laser diode switch element to generate a halftone cell or a resolution enhancing cell with desired gray scale pixels. The digital laser signal from the printer controller is passed through a digital-to-analog converter circuit to a comparator circuit. The particular waveform selected from the data storage area is also applied to the comparator circuit to modulate the output signal from the digital-to-analog converter. The analog modulated signal from the comparator circuit has an analog value that maintains the laser diode switch element "on" to provide sub-pixels for the particular pixel gray level that is desired.

Abstract: The present invention is directed to systems and methods for compressing image data while at the same time, improving both the compression ratio and the perceptibility of the decompressed image, even when the image data is compressed without segregation into its scanned and non-scanned components. In accordance with exemplary embodiments, color data is encoded in a manner which optimizes the color fidelity of a decompressed image obtained from the encoded color data. As a result, improved perceptibility of decompressed images is achieved regardless of whether scanned images, non-scanned images or any combination thereof are collectively compressed. Exemplary embodiments achieve such improved perceptibility regardless of whether the images are monochrome (having varying grey scale values) or color. In addition, improved perceptibility is realized in a manner which permits image data including scanned and/or unscanned images to be compressed in real-time.

Abstract: A system and method for efficient image compression begins by segmenting an input image into a current and previous window using a loading module. An encoding module compares the current and the previous window. If the current window does not match the previous window, the encoding module alters the dimensions of the current and previous windows and repeats the comparison. If a match is found, the encoding module instructs the loading module to continue to segment the image using the altered window dimensions. In this manner, the system's segmenting is in step with the natural cycle of repetition in the input image.

Abstract: The present invention is a method and system for reducing delays due to a stream of digital data processing requests to a function specific hardware circuit. The system includes a first hardware stage implemented to perform the given function and a second parallel software code stage implemented to perform the same function. The hardware stage employs circuitry to implement the function whereas the software stage performs the function using software code including function specific processor instructions. The system also includes an arbitration stage that routes the data values to either of the hardware or software stages depending on the availability of the hardware stage and in accordance to pre-defined arbitration rules.

Abstract: Disclosed is a technique for N-dimensional image data interpolation processing utilizing a multi-stage technique. Each stage processes one of the N-dimensions to constrain output data in that dimension. Subsequent processing in successive stages only occurs within the confines of the constrained output of the previous stage. Multiple data values can be simultaneously processed in the different stages, to pipeline the interpolation process.

Abstract: A system and method for changing an arbitration priority of a bus master are described. A changing system condition can be detected and used to signal the arbiter to change the priority of one or more bus masters. Timers can be provided to delay the request of a changed priority and to return a bus master to its default priority.

Abstract: Method and abstract for preparing pen-stroke image information for print on a raster-type output device. The image is first vectorized according to a slope classification technique which designates dots of a vector for print in repeating patterns depending on the slope class of the vector, in a manner which optimizes print speed without loss of print quality. In a novel post-processing step, the print data is scanned along a print line and any dot which is designated for print at a dot position less than or equal to s/2 dot positions beyond the previous dot designated for print is eliminated, and any dot designated for print more than s/2 dot positions from the previous dot position by less than s dot positions beyond the previous dot position is moved to s dot positions beyond the previous dot position, where s is the maximum distance apart at which two dots can be printed without loss of quality.