Abstract: The method of the present invention reduces a binary digital image in size by a factor F by a method including the steps of: storing the image in bit sequence; removing one or more rows of bits along the vertical axis of the image to convert i rows of bits to j rows of bits where 0.5i.ltoreq.j<i; modifying a line adjacent to each line discarded to preserve selected information from the discarded line; repeating the steps of removing and modifying a predetermined number of times to achieve a reduction by a factor F1 along the vertical axis; rotating the image in a first direction by ninety degrees; removing one or more rows of bits along the original horizontal axis of the image to convert i rows of bits to j rows of bits where 0.5i.ltoreq.

Abstract: A color quantization system for color image displays is disclosed which uses a three-dimensional histogram of an original color image to determine the particular colors of the image to be simultaneously displayed. The number of pels within each sub-space defined on a whole color space of the three-dimensional histogram is calculated, and the subspace having the largest number of pels is selected for display from among the sub-spaces, other than the sub-spaces represented by the colors which have been already selected for simultaneous display, if it is determined that the relationship ##EQU1## is satisfied, wherein M is said largest number of pels, N is the number of all the pels of the original color image to be displayed, A is the number of pels in the sub-spaces represented by the display colors which have already been determined, n1 is the number of all the colors to be simultaneously displayed, and n2 is the number of the colors which have been already determined for display.

Abstract: A system for producing improved halftone images from continuous tone input images, the pixels of which have been digitized as gray scale values, using a printer having the capability to print a set of output pel patterns producing a respective set of discrete gray scale values, is disclosed. Blocks of pel patterns with discrete gray scale values approximating the gray scale values of the input pixels are selected for printing, and the error in a first block due to the difference between the gray scale value associated with the block and the gray scale value of the corresponding input pixel, is determined. To diffuse this error it is distributed to at least two adjacent blocks using a random number generator to determine the distribution such that a random fraction of said error is distributed to one block and the remainder is distributed to the other block. This error diffusion process is carried through the adjacent blocks taking into account the error fraction already assigned.

Abstract: An electron beam position control arrangement for a color display cathode-ray tube, includes a series of spaced apart, parallel conductive strips on the faceplate or phosphor cooling of the CRT, the spaces between the strips defining a path along which an electron beam produced in the CRT is to be scanned. The electron beam is modulated with a pilot signal and, in the event the beam deviates along the predetermined path between the conductive strips, the pilot signal is detected as a result of the electron beam impinging on one of the strips by an amount greater than the beam impinges on an adjacent strip along the predetermined path, and the beam is returned to the predetermined path by position correction circuitry connected to beam deflection circuitry associated with the CRT.

Abstract: A system is shown for connecting a plurality of intelligent terminals through a central non-blocking switch to each other, to a partitioned memory and to one or more service processors to form a local area network.

Abstract: A method for rotating an image by 90 degrees includes the steps of: storing the image in a raster format arranged in r rows by c columns, image information in each row being stored in a number of bytes, each byte having b bits, there being c/b bytes in each row of the raster format; moving a block of the image into a temporary storage, there being r rows by v columns in the block; separating each image block into groups of bytes of rotatable size; determining for each group if all bits are the same value; rotating each group that does not have all bits the same value; storing each rotated group in an output area of the raster storage; repeating the above steps for all remaining blocks of the image.

Abstract: Method and apparatus is described for encoding and decoding a stream of randomly distributed binary bits representing digital data, including an encoder for encoding the bit stream to achieve a run length limited, partial response coding of the stream; a recording medium for recording the encoded stream; and a decoding system for recovering timing signals and a stream of data signals separately from the recorded stream using a first channel for decoding the recorded stream to recover a timing signal stream; therefrom; and a second channel for decoding the recorded stream to recover a stream of data signals therefrom.

Abstract: A method for converting an image from a bit map to a run end or run length representation includes the steps of: storing said image as a bit map representation; initializing all variables to be used in the conversion process; converting by table lookup, each run of continuous color to a run representation, storing, in a run representation buffer, as a count value, each run representation; repeating the steps of converting and storing for each run of continuous color to the end of the image.

Abstract: A method for converting an image from a run representation to a bit map, includes the steps of: storing a plurality of run representations of an image in a buffer; initializing a line of data; converting, by table lookup, each run representation, in said line, to a picture element representation, storing said picture element representation of said line; repeating the steps of initializing, converting and storing for remaining run representations until said image has been converted to a bit map representation.

Abstract: For designing the layout of a master-slice VLSI chip steps for placing components and for determining the wiring pattern interconnecting them are alternated in an iterative process. The chip area is partitioned into subareas of decreasing size, the set of components is partitioned into subsets which fit to the respective subareas, and after each partitioning step the global wiring is determined for the existing subnets of the whole network. Due to this interrelation of placement and wiring procedures, advantages with respect to total wire length, overflow number of wires, and processing time can be gained.

Abstract: A two-electrode nematic liquid crystal display (LCD) device with inherent storage effect is described. The described storage effect LCD device, which can properly operate without refresh circuitry, can be of either the homogeneous or twisted nematic type. In accordance with the invention, the liquid crystal material-to-substrate anisotropic surface anchoring force is set sufficiently weak by surface treatment techniques, to prevent the restoration of the device to its quiescent state once the device has been driven temporarily to its active state by a temporary increase in an applied electric field.

Abstract: The cache reload time in small computer systems is improved by using a distributed cache located on the memory chips. The large bandwidth between the main memory and cache is the usual on-chip interconnecting lines which avoids pin input/output problems. This distributed cache is achieved by the use of communicating random access memory chips of the type incorporating a primary port (10) and a secondary port (14). Ideally, the primary and secondary ports can run totally independently of each other. The primary port functions as in a typical dynamic random access memory and is the usual input/output path for the memory chips. The secondary port, which provides the distributed cache, makes use of a separate master/slave row buffer (15) which is normally isolated from the sense amplifier/latches. Once this master/slave row buffer is loaded, it can be accessed very fast, and the large bandwidth between the main memory array and the on-chip row buffer provides a very fast reload time for a cache miss.

Abstract: A method for expanding a binary image includes the steps of: storing the image in bit sequence; inserting for each string of 5 bits along a first axis one or more expansion bits, to convert each said string of 5 bits to a string of 6 bits; assigning a value to each expansion bit generated by the above step; inserting one or more rows of expansion bits for each 5 rows of bits along a second axis of the image to convert each 5 rows of bits to 6 rows of bits along the second axis of the image; assigning a value to each expansion bit generated by the above steps; storing the enlarged image generated by the above steps.

Abstract: A method and an apparatus are disclosed for converting error syndromes of an error-correcting code to pointers which identify the positions of the erroneous bits. Each syndrome is converted by a plurality of hashing functions into a plurality of hash words, which in turn are used to address a plurality of read-only stores. The outputs of the read-only stores are logically combined to obtain the respective error pointer. A preferred embodiment uses three hashing functions (41, 43, 45) and three read-only stores (53, 55, 57) and combines their outputs by an Exclusive-Or function (59). The storage capacity and the processing time required for syndrome-to-error pointer conversion are reduced by the disclosed scheme.

Abstract: Graphics images are generally considered to be those images comprised of text and/or line drawings. Data compression of graphics images is desired whenever a fast image transmission speed is desired in a limited band width channel. It is also used for storage of a large number of images in a limited capacity storage system. The method and apparatus described herein improves data compression, resolution and coding efficiency by eliminating transitions between gray levels at edges in an image, converting all gray levels to a common value to achieve a 3 level representation of a graphics image, and reversibly converting the 3 level representation to a bilevel double resolution representation by increasing the data sampling rate and therefore allowing the use of two level data compression techniques. A high resolution display or printed output may be obtained from the bilevel multiresolution representation.

Abstract: The overall arrangement of a number of non-overlapping rectangles with constraints on their size and shape, may be generated with relation to a number of objective functions such as, size and shape of the enveloping rectangle, size of an interconnecting network, and distance between pairs of individual rectangles, by first embedding a distance space, reflecting the desired proximity structure, in the plane; next, by refining containment relations, fixing the relative positions of rectangles within such a containment in accordance with the corresponding positions in the embedding; and on the basis thereof estimating the space required for the local realization of the interconnecting network in a configuration satisfying the constraints on the individual rectangles, and optimal with respect to any quasi-concave objective function on the dimensions of the enveloping rectangle that is monotone in its arguments. The method can be implemented even on relatively small computers.

Abstract: Graphic images are generally considered to be those images comprised of text and/or drawings. Data compression of graphics images is desired whenever a fast image transmission speed is desired in a limited band width channel. It is also used for storage of a large number of images in a limited capacity storage system. A high compression ratio is achieved by thresholding the graphics image to a bilevel black-white image at one bit per pixel and then employing a second data compression on the black-white image. At low resolution, bilevel images have poor quality at edges and a quality improvement is needed. The data compression apparatus and method disclosed separates the graphics image into at least first and second bit planes identifies edge pixels from the first bit plane indicating a black/white change, locates the edge pixels and generates at least a single bit for each edge pixel indicating whether the edge pixel has a maximum intensity value such as black or white or an intermediate gray intensity value.

Abstract: A four terminal liquid crystal display device includes orthogonally related row and column electrodes separated by a dielectric and disposed in respective sets above and below the liquid crystal medium. The electrodes in proximity to the LC medium are the column electrodes which have a small alternating square wave bias voltage.+-.Vo imposed therebetween so that a voltage of 2Vo magnitude is normally impressed across the LC medium. When an impulse voltage of magnitude 4Vo is impressed across the exterior row electrodes (+2Vo and -2Vo respectively), since the column electrodes are foraminated or have microapertures therethrough, the electric field established between the row and column electrodes in opposite sets, 3Vo, extends through the microapertures into the LC medium to establish a fringe electric field normal to the surfaces of the column electrodes tending to retain the LC directors in the vertical position.

Abstract: A locking device for a manually movable wheeled storage rack is described, which storage rack is provided with a manually operated rotatable handwheel, and power transmission mechanism for transmitting the rotational power imparted to the rotatable handwheel to drive wheels, thus causing the storage rack to be moved. The locking device is movable forward and backward in the axial direction thereof by manual operation at the rotatable center section of the rotatable handwheel. This locking device is capable of restricting the action of the power transmission mechanism, rendering the transmission of the motive force impossible, thus making the storage rack incapable of motion. This device can subsequently be released, thus rendering the movable rack once again capable of motion.