Abstract: A data processing system and method for performing a wavelet-like transformation and a corresponding inverse wavelet-like transformation is disclosed. The wavelet-like transformation is performed on input data so as to produce decomposed data. For each set of decomposed data samples of the decomposed data, each decomposed data sample of the set is produced by computing a weighted sum of a predefined set of data samples selected from (A) subsets of the set of input data samples, (B) one or more spatially shifted subsets of the set of input data samples, (C) the sets of decomposed data samples, and (D) one or more spatially shifted sets of the sets of decomposed data samples. The weighted sum is computed using only add and bit shift operations. Similarly, the inverse wavelet-like transformation is performed on decomposed data so as to produce reconstructed data.

Abstract: Conventionally, when compressing data, since data (words) are sequentially retrieved from the head of a dictionary, a large amount of time is required for compression processing. Particularly when compression/expansion processing is performed a plurality of times, a large amount of processing time is required. In order to solve such problems, input data is dealt with as a set of words having a specific number of bytes, and a word retrieval table having a size equal to or larger than the size of a dictionary for registering words is provided. By storing the position of each word registered in the dictionary in the word retrieval table, it is unnecessary to sequentially retrieve data (a word) from the head of the dictionary, so that compression/expansion processing can be promptly performed.

Abstract: An encoding/decoding method is provided for lossless compression of digital pictures of all types, including continuous-tone images, graphics, multimedia images of mixed text, graphics and photographs, binary documents and drawings. Continuous-tone mode and binary mode are identified on a pixel-by-pixel basis. In continuous-tone mode, context modeling and prediction are employed involving mostly integer arithmetic and simple logic in a conceptually sophisticated scheme. Both the encoding and decoding techniques are suitable for sequential and progressive transmission, although different specific algorithms may be employed for the different specific cases.

Abstract: A system and method is disclosed that compresses and decompresses images. The compression system and method includes an encoder which compresses images and stores such compressed images in a unique file format, and a decoder which decompresses images. The encoder optimizes the encoding process to accommodate different image types with fuzzy logic methods that automatically analyze and decompose a source image, classify its components, select the optimal compression method for each component, and determine the optimal parameters of the selected compression methods. The encoding methods include: a Reed Spline Filter, a discrete cosine transform, a differential pulse code modulator, an enhancement analyzer, an adaptive vector quantizer and a channel encoder to generate a plurality of data segments that contain the compressed image. The plurality of data segments are layered in the compressed file to optimize the decoding process.

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 system and method for compressing and decompressing datastreams with fractal coding is disclosed. The method includes the generation of an optimal data set transformation function corresponding to a representative datastream captured from a data source. The data set transformation function is determined by ordering the digits of the representative datastream to order the intervals of an attractor. The ordered intervals are then used to determine the mapping functions which define an optimal data set transformation function. The nodes or graphical representation of the data set transformation function are incorporated in a compressor/decompressor combination. The compressor receives data symbols from a data source and determines the next interval of an attractor using a composition operation. The address or a portion of the address is shifted out as a number representative of the data symbols. Preferably, the interval is renormalized so the interval may be represented in sixteen bits.

Abstract: In a method for storing and playback of a repertoire of fixed videotexts, in which the videotext is stored by characters in digital form in an electrical memory, the quantity of the data to be stored can be effectively reduced in that in addition to the characters, position characters are stored and that for recurring, identical character sequences of greater length, instead of the character sequence, a reference to the location of the already stored character sequence is stored. The playback of the thus compressed texts can take place without problems in real time, i.e., without noticeable delay.

Abstract: A video still camera in which an image of a photographic subject is converted to digital image data and the digital image data is compressed and stored in memory. The digital image data is first reversibly compressed by a high speed reversible encoder and temporarily stored in a buffer memory. The compressed data is then read from the buffer memory and restored by a reversible code regenerator, after which the restored data is irreversibly compressed and stored on a memory card. By compressing the stored image data before placing it in the buffer memory, the number of frames of image data possible for storage is increased. Furthermore, the capacity of the buffer memory may be decreased while maintaining transmission speed. The still camera may also include a code character memory which stores a code character representing the quantity of data encoded by the reversible encoder, and a parameter setting unit which sets parameters for controlling the irreversible data compression.

Abstract: The invention is embodied in an image data system including a lossy image compressor having an image compression ratio in excess of 10 for producing first compressed image data from an original image, the first compressed image data specifying a corresponding one of a set of predetermined images, apparatus for computing an difference between the original image and the predetermined image specified by the first compressed image data and a lossless image compressor for compressing at least the difference to produce second compressed image data.

Abstract: A method and apparatus for lossless compression and decompression of video image data. Video data is comprised of the RGB, YUV or gray scale (color) information for each pixel of each frame of the video data. Storage of such video data can require large amounts of data. The present invention provides for lossless compression and decompression of the individual frames of video image data. Each individual frame of video image data is processed in n.times.n pixel blocks. The combination of colors (called the color list) and the number of different colors in the pixel block is then determined. If the number of colors is above a predetermined threshold, no compression occurs. If the number of colors is below a predetermined threshold, searches for prior occurrences of the combination of colors is than performed. In some instances, a color list for contiguous pixel blocks will be the same. In this instance, a pixel map representing the positioning of the colors in the pixel block is output.

Abstract: A method for compressing digital image of more than a first predetermined number into the first predetermined number of bits in a substantially lossless manner includes determining a plurality of ranges in which input image data falls and comparing current image data with the plurality of ranges. The method further includes preserving a second predetermined number of bits of the current image data based upon which of the plurality of ranges the current image data falls to encode the current image data as an image value comprising the first predetermined number of bits.A system includes means for determining a plurality of ranges in which input image data falls and means for comparing current image data with the plurality of ranges, the means for comparing coupled to the means for determining.

Abstract: Digital input commands defined in a page description language are separated in two types of instructions: first instructions resulting in solid regions on the printed output and second instructions resulting in halftoned regions. The first instructions generate a binary bitmap indicating a high or low density of the solid regions and a binary bitmask indicating whether recorder elements belong to a solid or screened region. The bitmap and bitmask are preferentially compressed by a lossless compression method. The second type of instructions generate a contone map, representing images having contone levels and graphics having intermediate levels. The contone map is preferentially compressed by a lossy compression method, stored on a storage medium and retrieved once the output device must render the rasterized image. The rasterized image is constructed on the fly from the compressed bitmap, bitmask and contone map, which is halftoned before combination with the bitmap.

Abstract: A compressing method consisting of generating a predicted value for the pixel of the digitized image to be compressed based on the values of at least two neighboring pixels is provided. After calculating the difference between the predicted value and the current pixel value, a prediction error is defined by a one-on-one mapping on the difference obtained. According to an advantageous feature of the mapping relationship, the required number of bits for representing the prediction error is less than that required for the difference per se. Afterwards, a parameter K is generated which is in proportion to the difference between the neighboring pixels used in prediction. According to the respective values of the parameter K, the next step is to encode each prediction error by assigning a variable-length Rice code to the prediction error of each pixel.

Abstract: The digital information encoding device for high speed processing based on a QM-Coder, which comprises a context table storage means having a read/write context table storage portion for storing a plurality of storing data comprising a prediction symbol and a probability estimating data, comprises two port RAM, wherein a storing data stored in the context table storage portion at the address based on the context received at a read address input node AR is directly outputted to an arithmetic calculation means via a data output node DO.

Abstract: A method for estimating high frequency components of a compressed image normally lost during a data compression stage and an encoder and a decoder for carrying out same. The image is compressed to obtain unquantized and quantized frequency domain coefficients. An inverse quantization is performed on the quantized coefficients to obtain lossy frequency domain coefficients. Loss characteristics of the high frequency components are then determined based on the unquantized frequency domain coefficients and the lossy frequency domain coefficients according to one of several methods. Finally, the loss characteristics are coded to obtain encoded loss data corresponding to the lost high frequency components.

Abstract: This invention has as its object to provide an image coding method which can efficiently encode image data by fully utilizing a two-dimensional correlation of an image. A block matching means searches for a block position corresponding to a minimum absolute value sum of differences of a pixel block to be encoded from already encoded pixel blocks. The searched block position information is encoded by an encoder, and the searched inter-block difference value is Huffman-encoded by another encoder. A code generator generates encoded data using these codes.

Abstract: A method and apparatus for performing color conversion on image data provided as a plurality of vectors representing a datum of the image. The present invention provides a forward transform that performs reversible color conversion on the plurality of vectors, such that the transform is reversible in integer arithmetic with predictable precision.

Abstract: A transportable medical image storage medium includes a recordable optical compact disk. The compact disk has a first storage area which records a plurality of substantially losslessly compressed digital medical images and a second storage area which records a plurality of lossy compressed digital medical images corresponding to said losslessly compressed medical images. Where a case study or set of medical images is of such a length that more than one CD is required to record all of the losslessly compressed digital medical images, each CD records the entire set of lossy compressed digital medical images.

Abstract: An identification code signal is impressed on a carrier to be identified (such as an electronic data signal or a physical medium) in a manner that permits the identification signal later to be discerned and the carrier thereby identified. The method and apparatus are characterized by robustness despite degradation of the encoded carrier, and by permeation of the identification signal throughout the carrier.

Abstract: Methods and systems for encoding data representative of a sequence of video frames for transmission to a decoder. A motion compensated predictive coder (24) substantially losslessly compresses the data, computes a motion vector, and forms an intermediate coded representation which includes the compressed data and the motion vector. A frame detector (26), which detects frames having a prediction error which exceeds a predetermined threshold, is coupled to the motion compensated predictive coder (24). A digital storage device (22) is coupled to the motion compensated predictive coder (24) and the frame detector (26). The digital storage device (22) stores the intermediate coded representation and stores a representation of the frames having the prediction error which exceeds the predetermined threshold. A lossless decoder (29), coupled to the digital storage device (22), substantially losslessly decodes the intermediate coded representation to form a decoded representation.

Abstract: A data compression and decompression technique compresses a binary stream of digital data into compressed form and decompresses a compressed data stream into decompressed form without any loss of fidelity. The techniques require very little processing time to permit compression and decompression of digital data quickly. Once the digital data is compressed into compressed form, the amount of memory required to store the compressed digital data is much less than the amount of memory required to store the corresponding data in uncompressed form.

Abstract: A fingerprint image transmission system includes a remote computer system and a central computer system. In the remote computer system, a gray image of a fingerprint image sampled by an image scanner portion (10) is compressed by a non-reversible (lossy) coding by a non-reversible coding mechanism (202) and a skeleton pattern generated by a skeleton generating mechanism (201) by inputting the gray image, is compressed by a reversible (lossless) coding by a reversible coding mechanism (203). The compressed gray image and the compressed skeleton pattern are transmitted to the central computer system through a transmission mechanism (31). In the central computer system, a receiver mechanism (41) receives the gray image and the skeleton pattern transmitted from the remote computer system.

Abstract: Digital input commands defined in a page description language are separated in two types of instructions: first instructions resulting in solid regions on the printed output and second instructions resulting in halftoned regions. The first instructions generate a binary bitmap indicating a high or low density of the solid regions and a binary bitmask indicating whether recorder elements belong to a solid or screened region. The bitmap and bitmask are preferentially compressed by a lossless compression method. The second type of instructions generate a contone map, representing images having contone levels and graphics having intermediate levels. The contone map is preferentially compressed by a lossy compression method, stored on a storage medium and retrieved once the output device must render the rasterized image. The rasterized image is constructed on the fly from the compressed bitmap, bitmask and contone map, which is halftoned before combination with the bitmap.