Abstract: A method for approximating a contour of an object expressed in a digital video signal divides the contour into a multiplicity of primary contour segments and approximates each primary contour segment by a primary line segment, to thereby calculate a set of errors between the primary contour segment and the primary line segment for each primary contour segment. And the method codes and decodes the set of errors, to thereby generate of a set of reconstructed errors and a reconstructed contour segment which are used to determine a reconstruction error. Thereafter, the method generates one or more secondary contour segment on the primary contour segment with each secondary contour segments approximated by a secondary line segment. Subsequently, the method finds an approximation error and approximates said each primary contour segment by using either the reconstructed contour segment or the secondary line segments based on the reconstruction error and the approximation error.

Abstract: A method encodes a contour of an object expressed in a digital video signal, the video signal having a plurality of video frames including a current and a previous frames, by using an improved contour motion estimation. Centroids of a current and a previous contours are first determined by averaging pixel positions on each contour, respectively, and a displacement therebetween is outputted as a motion vector. The previous contour is shifted based on the motion vector in order to produce the predicted current contour. Deviation information representing the difference between the predicted current and the current contours is detected based on the predicted current and the current contours and the centroid of the current contour and then is encoded.

Abstract: In a compression system, three-dimensional geometry is first represented as a generalized triangle mesh, a data structure that allows each instance of a vertex in a linear stream to specify an average of two triangles. Individual positions, colors, and normals are quantized, preferably quantizing normals using a novel translation to non-rectilinear representation. A variable length compression is applied to individual positions, colors, and normals. The quantized values are then delta-compression encoded between neighbors, followed by a modified Huffman compression for positions and colors. A table-based approach is used for normals. Decompression reverses this process. The decompressed stream of triangle data may then be passed to a traditional rendering pipeline, where it is processed in full floating point accuracy.

Abstract: An apparatus for encoding a contour of an object determines a number of vertex points based on a polygonal approximation to the contour. A set of approximation errors calculated at a predetermined number of sample points on each line segment between two adjacent vertex points is transformed to obtain a corresponding set of transform coefficients. The apparatus converts, in response to a masking range designation signal corresponding to each line segment, a part of the set of transform coefficients to zeros and produces a set of masked transform coefficients corresponding thereto. The set of masked transform coefficients is quantized and encoded to be transmitted through a transmitter.

Abstract: A contour coding method adaptively encodes a contour image in a video frame based on the size and complexity of the contour image in order to improve the quality of a reconstructed contour image. First, the size and complexity of the contour image inputted are determined. Simultaneously, the contour image is encoded by using a first and a second contour coding methods to thereby provide first and second coded contour data, respectively. And, the first or the second coded contour data is selected as encoded contour image data based on the size and complexity of the contour image.

Abstract: A contour approximation method accurately reconstructs a contour of an object by adding an extra vertex to the complex contour segment based on a curvature of the pixels on the contour image. The target pixel having the largest curvature as the extra vertex is selected.

Abstract: A method (900, 1000) and device (100, 600) are provided for encoding and/or decoding a compact representation of a discrete region contour for the purposes of image and video compression. The compact representation described provides bitstream scalability so that progressively larger subsets of the compact representation can be used to provide progressive better quality in the approximate reconstruction of the discrete region contours. The resulting device and method provide for coding of shape information within object-based and region-based image and video compression systems.

Abstract: A method for encoding a video signal of a current contour of an object based on a previous contour thereof determines a multiple number of first vertex points on the current contour and maps the first vertex points onto the previous contour to thereby provide second vertex points of said multiple number on the previous contour. After approximating the current contour based on the first vertex points to thereby provide a first approximation contour and approximating the previous contour based on the second vertex points to thereby provide a second approximated contour, the method obtains a first set of approximation errors between the current contour and the first approximated contour and a second set of approximation errors between the previous contour and the second approximated contour. The method then calculates a difference between the first and the second sets of approximation errors and encodes the difference to produce encoded data.

Abstract: The feature points of the input video signal are detected by canny edge detecting method, the coordinates of the feature points detected are detected is chain coded, the length of the region, including the feature points, of which edge intensity is the specified value or more in the edge intensity maximum change direction at the feature point coordinates obtained when the feature point is detected, are coded. The chain-coded data and the region length coded data are then multiplexed. Thereby, the amount of bits required for coding of the coordinates information can be reduced, as a result the total amount of codes can be reduced.

Abstract: An apparatus for tracing contours of segmented regions in an image includes a zero masking unit to produce a closed contour loop for each of the segmented regions, a tracing circuit for sequentially assigning each of the non-zero masked pixels on the closed contour loop as a tracing pixel, comparing the tracing pixel with a set of its adjacent pixels located at a rightward, an upward, a leftward and a downward directions with respect to the tracing pixel to select one of the adjacent pixels having a luminance level identical to that of the tracing pixel and updating the tracing pixel with the selected adjacent pixel with until the updated tracing pixel coincides with the tracing pixel selected first.

Abstract: A set of first errors selected from sets of errors indexed as, e.g., sets of first to Kth errors between contour segments and corresponding line segments at a predetermined number of sample points on each of line segments, K being a positive integer, fitted to a contour of an object in a video signal by using a polygonal approximation method is encoded and decoded after being transformed and quantized to thereby generate an encoded set of first errors and a decoded set of first errors. Thereafter, the process described hereinafter is repeated for all the remaining sets of errors, from a set of second errors to a set of Kth errors, to thereby generate all the remaining encoded and decoded sets of errors.

Abstract: An apparatus for encoding a contour of regions contained in a video signal comprises first and second segmentation blocks for segmenting previous and current frame into a number of regions to generate previous and current contours, a prediction parameter calculation block for generating prediction parameters based on the previous and current contours, and the previous and current frames, a contour prediction block for constructing a predicted current contour by transforming the previous contour based on the prediction parameters, an error detection block for detecting deviation points lying on portions of the predicted current contour that deviate from the current contour, thereby generating the deviation points and corresponding displacements to the deviation points, and a contour coder for encoding the deviation points and the displacements together with the prediction parameters.

Abstract: Geometric data for a three-dimensional surface are compressed in regard to the data representing the continuity between triangles in a mesh that represents the three-dimensional surface. The geometric data include information defining the vertices of the triangles comprising the mesh, an indication of the triangle faces, and corner normals to each of the vertices shared by triangles having a common vertex, which indicates the continuity or discontinuity between adjacent triangles of the surface. Vertex rotation continuity (VRC) data are determined for each vertex shared by adjacent triangles, indicating whether the transition between the adjacent triangles is continuous or discontinuous. Further, a dihedral angle between each pair of adjacent triangles is determined and associated with the VRC bit. The VRC data are sorted by the associated dihedral angles, enabling an optimal dihedral angle to be selected.

Abstract: In a picture encoding and decoding method and apparatus, an object contour can be chain coded precisely even in the case where noise exists in the vicinity of object contour, and the object contour branched off can be coded with small quantity of codes. In the case where the branched part occurs in a feature point chain, by multiplexing branch code D1 to chain codes S23 and S22 and expressing as a tree structured feature point chain including the branch part of the object contour, an increase in number of chains can be controlled and the efficient chain coding can be conducted. Moreover, since the terminal branch chains having no branch point in the chain become the objects of thresholding, only noise elements can be effectively eliminated without cutting off the feature point chain showing the object contours.

Abstract: An apparatus for encoding a input video signal having a plurality of video frames each of which may be divided into a multiplicity of non-overlapping blocks of K.times.K pixels by using a modified BTC method and a contour coding method, with the apparatus including a masking block for providing a binary frame of the input video signal, a contour coding block for generating contour and binary information for the binary frame, a control block, for each binary block derived from the binary frame, for determining a number L and a control signal, a modified BTC block, for each video block derived from the input video signal, for generating a mean value and two reconstruction values based on intensity values of the K.times.K pixels within each video block and the number L, and selecting either the mean value or the two reconstruction values in response to the control signal.

Abstract: A contour encoding apparatus determines vertex points on the previous contour of the previous frame based on a polygonal approximation. A set of first approximation errors is calculated at a predetermined number of sample points on each first line segment between two vertex points, and a first set of discrete sine transform coefficients is obtained by discrete sine transforming the set of first approximation errors for each first line segment. Predicted vertex points are detected based on the vertex information and current contour of the current frame. A set of second approximation errors is calculated at the predetermined number of sample points on each second line segment between two predicted vertex points, and a second set of discrete sine transform coefficients is obtained by discrete sine transforming the set of second approximation errors for each second line segment.

Abstract: An encoding system effectively reduces the substantial amount of data for transmission by way of employing three encoding channels which perform a compression process for individually extracting and coding the contour of the approximated foreground region consisting of a still object, the boundary pixel values of the pixels located on the contour and the leveled-down/trimmed pixel data corresponding to the contour and the boundary pixel values. Further, a decoding system for use with the encoding system serves to effectively perform a decoding process for a coded image signal by using three decoding channels containing the decoding path for restoring pixel information including a set of reconstructed boundary pixel values and reconstructed contour information.

Abstract: An outline font data is converted into dot data, based on which a dot image is printed. When an image represented by the outline font data has a very narrow portion or very steep end portion, whether or not dots have been prepared at picture elements surrounding that portion is examined. Then, a dot is prepared at a position that can smoothly connect those dots. Even at this narrow portion, no dots will strangely protrude from the entire shape of the produced dot image.

Abstract: A method for processing three-dimensional shape data includes steps of obtaining a plurality of point data along a surface of an object having a three-dimensional shape; taking out a point data from the obtained point data to be processed, approximating each specified number of point data in the to-be-processed point data adjacent the taken-out point data by a polynomial and then finding two unit vectors at the taken-out point data; finding an opening angle defined between the two found unit vectors; comparing the found opening angle with a predetermined threshold value of the opening angle, determining whether or not the found opening angle is not larger than the threshold value, and thinning the taken-out point data when the found opening angle is larger than the threshold value and not storing the taken-out point data in a storage unit, and leaving the taken-out point data without the thinning when the found opening angle is not larger than the threshold value and storing the taken-out point data in the st

Abstract: A method of coding digital image data of an original image for transmission and reproduction. The original image is subdivided into partial image regions whose shapes are adapted to local image structures. For each partial image region, a set of two-dimensional, lineraly independent basis functions is provided. The areal expanse of the basis functions approximately corresponds to the size of a rectangle circumscribing the partial image region to be coded and the raster of the sampled values of the basis functions corresponds to the pixel raster of the original image. The sampled values of the basis functions disposed within the area defined by the partial image region are orthogonalized in order to obtain a set of new, orthogonal basis functions, with the set including as many orthogonal basis functions as there are pixels within the partial image region. Coefficients of the orthogonalized basis functions describing the partial image region are then calculated.

Abstract: A method of compressing and decompressing a multi-dimensional image. Video data including luminance data distributed at least in two-dimensions is compressed for subsequent coding. The resulting codes are decompressed to reproduce the video data. A specific number of representative pixels are extracted from a plurality of pixels consisting of the digital signal of the video data. Texture data is also extracted from the digital signal of the video data. The representative pixels and the texture data are coded. The coded representative pixels and the texture data are then decoded. The video data is reproduced using the decoded representative pixels and the texture data.

Abstract: A method for encoding a contour of an object predicts a current contour by using a current and a reconstructed previous contours and generates the motion vector representing a displacement between the reconstructed previous and the predicted current contours. A matched contour between the predicted current and the current contours is subtracted from the current contour to provide a differential contour. Thereafter, vertex points is determined based on a polygonal approximation for the differential contour. A set of approximation errors calculated at a predetermined number of sample points on each line segment between two vertex points is transformed and quantized to obtain a set of quantized discrete sine transform coefficients. The quantized discrete sine transform coefficients are encoded together with the motion vector, and the vertex points are encoded based on the predicted current contour for transmission thereof.

Abstract: A processing block is processed by using an extension-interpolation ("E-I") method, wherein the processing block consisting of N.times.

Abstract: A method and apparatus for generating a reconstructed image from a compressed image. An exemplary method in accordance with the present invention includes the steps of identifying pairs of compressed image data points having a connection therebetween in a linear segment approximation of the reconstructed image; estimating timing information such as a number of original image data points between each of the connected pairs of compressed image data points; and fitting a spline segment to each of the pairs of compressed image data points and the estimated number of original image data points corresponding thereto, such that the fitted spline segments in combination form the reconstructed image. The reconstructed image may then be smoothed by replacing spline segments which produce undesirable deviations in the reconstructed image with conic section spline segments.

Abstract: A data converting apparatus and process for converting outline representations of a character into its bit mapped form using two buffers one being for the bit mapped form of the character symbol and the other for the chain-code representation of the outline of the character are disclosed. Three steps are utilized in the process. The first step draws the character outline on to the drawing buffer and generates the chain-code representation with flags to indicate contour collisions. The contours are then scanned one more time to add missing flags on the chain-code representation. Finally, the inside part of the contour on the drawing buffer is filled using the chain-code representations of the contour, to provide a filled character.

Abstract: A moving image transmission method encodes and decodes information to obtain a high transmission efficiency. The coding method calculates motion parameters of each segment of an image and segment prediction is conducted between frames. The encoder of the sending end and the decoder of the receiving end independently determine each respective segment for n frames (n is a natural number) in which encoding has been completed. To predict the corresponding portion of the present frame, the encoder calculates the required motion parameters, and then sends these motion parameters with the coded information to the decoder. In the decoder, prediction between frames is performed using the segment information independently determined with regard to the image of the previous frame in addition to the coded information and motion parameters received from the encoder.

Abstract: An image processing system encodes a segmented or mosaic image into a set of fixed-length data packets, from which the segmented image may be reproduced with no significant loss of detail. The exemplary system includes a chain coder which translates the segmented image into a form in which the image segments are represented as respective sequences of border values, each border value indicating a direction to the next border value. This image is further encoded such that each pair of border values becomes a single further border value and a pair of complementary codes. These further border values are processed in the same manner, to further reduce the number of border values needed to represent the image. When the number of border values has been reduced to a level such that the image may be encoded in a single packet, the encoding system provides these border values and all complementary code values that have been generated as the code representing the segmented image.

Abstract: A method of compressing inputting two-dimensional object, compressing the two-dimensional data in a short time to a small amount of data and reproducing in any size at any position. This invention reads two dimensional object, e.g. characters, figures, drawings or Illustrations optically, extracts peripheral points from a binary image, approximates the peripheral lines by Fluency functions, reckons curvatures at all points, and finds joints. The peripheral points series are divided by the joints. The lines between two neighboring joints are approximated by straight lines, arcs and free curves in this order. The free curves are approximated by linear combinations of Fluency functions. Adoption of joints greatly alleviates the quantity of data. Approximation by Fluency functions heightens the quality of the reproduced objects.

Abstract: A compression and decompression method using a wavelet decomposition, frequency based tree encoding, tree based motion encoding, frequency weighted quantization, Huffman encoding, and tree based activity estimation for bit rate control. Forward and inverse quasi-perfect reconstruction transforms are used to generate the wavelet decomposition and to reconstruct data values close to the original data values. The forward and inverse quasi-perfect reconstruction transforms utilize special filters at the boundaries of the data being transformed and/or inverse transformed.

Abstract: An image processing system which processes image data on a line by line basis. Edges in the images are detected as discontinuities in intensity. The intensity profile between detected edges is determined and matched to a polynomial function. Data representing the detected edges and data relating to the detected profile are stored as a data set for further processing. The data set for one image may be compared to that for another similar image in order to match features between images and thereby produce three-dimensional information about a scene.

Abstract: A device for coding still images has a device for segmenting the images into homogeneous regions whereto a specific label is attached, and a device for coding the contents of the contour. The contour coding device has a sub-assembly which detects contours for each regions, for each region successively considered, it detects points which are to form a series of control points and transforming the part of the contour joining two successive control points into a straight segment. Then the validity criterion is verified. If the criterion is not met, at least one supplementary control point is introduced between the two control points and so on until it is. The transformation is applied until the contour loop is completely closed.

Abstract: A handwritten character recognition device including: input unit for inputting handwriting thereon; stroke extracting unit for analyzing the handwriting in an X-axis and Y-axis direction, and extracting an X-axis and Y-axis direction input stroke; symbolizing unit for converting the X-axis direction input stroke into an X-axis direction symbol string and the Y-axis direction input stroke into a Y-axis direction symbol string; first storage unit for storing X-axis direction basic symbol strings corresponding to X-axis direction basic symbol strokes of reference characters, and Y-axis direction basic symbol strings corresponding to Y-axis direction basic symbol strokes of the reference characters; second storage unit for storing correlation coefficients between each of the symbols; degree-of-match calculating unit for calculating, by referring to the first storage unit and the second storage unit, X-axis correlation coefficients between the symbols forming the X-axis direction symbol string and the symbols form