Abstract: An article of insulation includes a plurality of containers supported by at least one support layer. Each of the containers have rigid walls which enclose either a vacuum or a gas. When in water, the rigid-wall containers provide insulation and buoyancy which makes the insulation ideal for clothing and wet suits. These properties may be enhanced by making the support layer from thermal insulation material and/or one which itself exhibits a desired buoyancy. The containers may be formed as beads which are spherical or non-spherical in shape, or the containers may have a tubular shape. Further, the beads may all be of the same size or the sizes may be varied to achieve desired buoyancy and/or insulation properties. A wet suit made from this insulation outperforms conventional wet suits in terms of insulation, buoyancy, comfort, safety, thinness, and functionality. An article of clothing made from this insulation may be used to keep a wearer afloat until help arrives.

Abstract: Increased and potentially extreme compression of documents is achieved by reducing/remapping the dynamic range of the document image possibly together with further image analysis and pre-processing and storing the document together with a substituted table of values chosen to restore or enhance the dynamic range of the document image. Increased or extreme compression is provided notwithstanding multiple image tones (e.g. colors or grey scale levels) even at low contrast within a document, such as a personal check. Such increased compression allows document images to be maintained in rapid-access memory for extended periods without increased storage costs.

Abstract: JPEG (Joint Photographic Experts Group) images are encoded and decoded as fast as possible for a variety of disparate applications. A novel structure stores the 8×8 Discrete Cosine Transform (DCT) blocks after entropy decoding in a JPEG decoder or after the Forward Discrete Cosine Transform (FDCT) in the JPEG encoder to use as an intermediate format between transform processes. The format was chosen to speed up the entropy decode and encode processes and is based on the information needed for the JPEG Huffman entropy coding, but lends itself to fast execution of other DCT based transforms, including arithmetic entropy coding.

Abstract: Huffman encoding, particularly from a packed data format, is simplified by using two different table formats depending on code length. Huffman tables are also reduced in size thereby. Decoding is performed in reduced time by testing for the length of valid Huffman codes in a compressed data stream and using an offset corresponding to a test criterion yielding a particular test result to provide a direct index into Huffman table symbol values while greatly reducing the size of look-up tables used for such a purpose.

Abstract: Improved apparatus and method for encoding and decoding information is disclosed herein. The invention uses the same marker segment information to engage an encoder or a decoder. The technique eliminates many of the complexities associated with building parameter lists, and generating various types of marker segments in a form compatible with both the decode and encode processing.

Abstract: The present invention relates to computer apparatus and methodology for adapting the value of a probability of the occurrence of a first of two binary symbols which includes (a) maintaining a count of the number k of occurrences of the first symbol; (b) maintaining a total count of the number n of occurrences of all symbols; (c) selecting confidence limits for the probability; and (d) when the probability is outside the confidence limits, effectuating a revision in the value of the probability directed toward restoring confidence in the probability value. The number of allowed probabilities is, optionally, less than the total number of possible probabilities given the probability precision. Moreover, an approximation is employed which limits the number of probabilities to which a current probability can be changed, thereby enabling the probability adaptation to be implemented as a deterministic finite state machine.

Abstract: A system and method for maximizing data compression by optimizing model selection during coding of an input stream of data symbols, wherein at least two models are run and compared, and the model with the best coding performance for a given-size segment or block of compressed data is selected such that only its block is used in an output data stream. The best performance is determined by 1) respectively producing comparable-size blocks of compressed data from the input stream with the use of the two, or more, models and 2) selecting the model which compresses the most input data. In the preferred embodiment, respective strings of data are produced with each model from the symbol data and are coded with an adaptive arithmetic coder into the compressed data. Each block of compressed data is started by coding the decision to use the model currently being run and all models start with the arithmetic coder parameters established at the end of the preceding block.

Abstract: Apparatus and method for adapting the estimated probability of either the less likely or more likely outcome (event) of a binary decision in a sequence of binary decisions involves the up-dating of the estimated probability in response to the renormalization of an augend A. The augend A changes value with each binary decision, the size of the change depending on which of the binary events has occurred as input. Re-normalization of A occurs when the A value becomes less than a prescribed minimum value AMIN. According to the invention, there may be differing contexts in which binary decisions may occur, each context having a corresponding estimated probability value which is up-dated with binary decisions in the respective context. Also according to the invention, there may be one or more possible next values for an estimated probability in response to a given binary decision event.

Abstract: The present invention relates to computer apparatus and methodology for adapting the value of a probability of the occurrence of a first of two binary symbols which includes (a) maintaining a count of the number k of occurrences of the first symbol; (b) maintaining a total count of the number n of occurrences of all symbols; (c) selecting confidence limits for the probability; and (d) when the probability is outside the confidence limits, effectuating a revision in the value of the probability directed toward restoring confidence in the probability value. The number of allowed probabilities is, optionally, less than the total number of possible probabilities given the probability precision. Moreover, an approximation is employed which limits the number of probabilities to which a current probability can be changed, thereby enabling the probability adaptation to be implemented as a deterministic finite state machine.

Abstract: Apparatus and method for compressing and de-compressing binary decision data by arithmetic coding and decoding wherein the estimated probability Qe of the less probable of the two decision events, or outcomes, adapts as decisions are successively encoded. To facilitate coding computations, an augend value A for the current number line interval is held to approximate one by renormalizing A whenever it becomes less than a prescribed minimum AMIN. When A is renormalized, the value of Qe is up-dated. The renormalization of A and up-dating of Qe are preferably based on a single-bit test. Also, each Qe value is preferably specified as a 12-bit value having the least significant bit set to 1 and having no more than four other bits set to 1. The number of Qe values in the 1/4 to 1/2 probability range is enhanced to improve coding efficiency.

Abstract: A data compression/de-compression system includes a first arithmetic coding encoder, characterized by a first set of encoding conventions, which encoder generates a code stream that points to an interval along a number line in response to decision event inputs. The code stream can be adjusted to point to the same interval as code streams generated by one or more other arithmetic coding encoders characterized by encoding conventions differing in some way from those in the first set. In a binary context, optimal hardware encoders increment or decrement the value of the code stream in response to each occurrence of a more probable decision event while optimal software so changes the code stream value for each occurrence of a less likely event. According to the invention, the code streams for optimal hardware encoders and optimal software encoders are made either identical or compatible to enable similar decoding for each.

Abstract: A method for encoding and decoding digital image data, includes the steps of: testing the data for a vertical relationship between adjacent lines of the image; generating directly a reference code word representative of the vertical relationship for each successful test; generating by table lookup a run code word for a stream of data bits of common value for each unsuccessful test whereby a data element representing a number of bits in a code word is stored at a predetermined offset from a table entry for the code word; merging the vertical reference code words and the run code words generated by the above steps to form an encoded data stream; testing the encoded data stream for a reference code; decoding directly the vertical relationship from the reference code for each successful test; decoding by table lookup a run of bits of common value by serial examination of said encoded data stream for each unsuccessful test; and storing data decoded by the above steps in a predetermined relationship.

Abstract: Digital data defining images are stored in a multiplane buffer. The buffer may store plural images by restricting data corresponding to an image or image portion to storage in less than half the bit planes of the buffer. An image is displayed by reading data from the buffer and selectively passing only a portion of the data read to a display. The data defining the images may be converted from facsimile (single bit per pixel) to gray scale format (multiple bits per pel) before being written to the buffer. The conversion relies on a table storing data definitive of the effect, on the image, of a facsimile transition (1/0 ot 0/1) as a function of the location of the transition. Conversion from facsimile to gray scale is effected by examining the facsimile data for data transmission and summing the effect of each of the transitions to convert a segment of facsimile data to gray scale data.A system is also disclosed for rapidly converting an image in run-end form to a reduced-resolution gray-tone image.

Abstract: In an image in which some pixels in some rows of an image have values associated therewith, apparatus and method of processing, for subsequent entropy coding or decoding, graylevel data for the remaining pixels in the image.

Abstract: A method for suppressing the perception of flicker in interlaced video images, includes the steps of: testing, each pixel in an image, for an intensity value below a first predetermined threshold; modifying, for each tested pixel, an intensity value representation for each nearest neighbor pixel along a first axis of said interlaced image having an intensity value exceeding a second predetermined threshold, if the intensity value of the tested pixel is below the first predetermined threshold; displaying, on a video display device, an interlaced image generated by the steps of testing and modifying, having a suppressed perception of flicker.

Abstract: A high speed form of finite precision binary arithmetic coding comprises encoding/decoding performed in the logarithm domain, resulting in facilitated computation based on additions and subtractions rather than multiplications and divisions. In encoding and decoding, antilogs are used which are retrieved from an antilog table. The antilog table is characterized by the following constraints to assure decodability wherein for any two mantissas .alpha. and .beta. representing respective inputs to the antilog table:(a) antilog (.alpha.+.beta.).ltoreq.antilog (.alpha.) * antilog (.beta.); at least when (.alpha.+.beta.) is less than one; and(b) each antilog table output value is to be unique.

Abstract: A system for formatting electronic binary image data, which may be in compressed raster form, into transposed or rotated raster form for storage or output, such as on a printing device, is disclosed wherein the image data is first assembled in a buffer in the form of vectors of run ends representing successive raster scan lines of an original image to be reproduced. The elements of an intermediate buffer are initialized to zero and the data is entered into the intermediate buffer by using each run end to set a bit in the intermediate buffer, with the bits being set in the buffer elements in correspondence with the respective raster positions of the run ends. The elements of the intermediate buffer containing the entered electronic data are then combined, such as by EXCLUSIVE-ORing, to create transposed or rotated raster data, which may stored or input to a suitable output device, such as a printer or display.

Abstract: Apparatus and method for modelling differential pulse code modulation (DPCM) input data for entropy coding. In particular, the sign and magnitude of one piece of DPCM data after another are modelled to provide a magnitude state input and a sign state input to provide context for DPCM magnitude input and DPCM sign input, respectively, to an entropy encoder or decoder. That is, the DPCM magnitudes of earlier pieces of (context) DPCM magnitude data are re-mapped for each such earlier piece of data, the re-mapped data being aggregated to form a combined value indicative of the magnitude state input. Similarly, the DPCM signs of earlier pieces of (context) DPCM sign data are re-mapped for each such earlier piece of data, the re-mapped data being aggregated to form a combined value indicative of the sign state input. In an image data compression system, the magnitude state input serves as an activity indicator for picture elements (pixels) neighboring a "subject" pixel.

Abstract: A method for encoding and decoding digital image data, includes the steps of: testing the data for a vertical relationship between adjacent lines of the image; generating directly a reference code word representative of the vertical relationship for each successful test; generating by table lookup a run code word for a stream of data bits of common value for each unsuccessful test whereby a data element representing a number of bits in a code word is stored at a predetermined offset from a table entry for the code word; merging the vertical reference code words and the run code words generated by the above steps to form an encoded data stream; testing the encoded data stream for a reference code; decoding directly the vertical relationship from the reference code for each successful test; decoding by table lookup a run of bits of common value by serial examination of said encoded data stream for each unsuccessful test; and storing data decoded by the above steps in a predetermined relationship.

Abstract: A method and apparatus for converting an image in run representation form into a raster image which is rotated by some multiple of 90.degree. from the orientation of the original image is disclosed wherein the original image data which is stored in run end or run length form may be divided and stored in discontiguous blocks. In implementing a 90.degree. rotation, the image data is conceptually divided into vertical strips, each of which is independently rotated to create a horizontal strip of the output image. The rotation process is carried out by firstly converting the run representation image data to raster form, dividing the data in each row among a number of intermediate buffers, each of which contains the data from one vertical strip of the original image. The contents of each buffer are rotated and rearranged in an available buffer to form a horizontal strip of the rotated image ready for raster readout. Similarly, a convenient method of rotating the input image 180.degree.