Abstract: A method of representing a digital image to provide a coded representation is disclosed. The digital image is divided into a number of blocks of pixels and each block is transformed to derive a block of transform coefficients, each transform coefficient being represented by a predefined bit sequence. Each block of transform coefficients is selected in turn as a region and a predetermined maximum bit plane is set as the current bit plane. This is followed by scanning the significances of each bitplane of the selected region from the current bitplane towards a predetermined minimum bitplane, and providing a first token for each insignificant bitplane and a second token for a significant bitplane in the code representation until a significant bitplane is determined and the determined significant bitplane is set as the current bitplane. The selected region is partitioned into two or more subregions having a predetermined form, and setting each of the subregions as the selected region.

Abstract: A method and apparatus for compressing video data images uses optical processing techniques. The method and apparatus perform holographic optical correlation and apply holographic optical correlation in a feedback loop. A codebook of images or primitives for the correlation are stored in a holographic library.

Abstract: An image processing method for processing a grayscale image, by which grayscale images of color or monochrome photographs characters and so on are processed by being converted into digital signals, and by which the data amount of image signals are compressed and grayscale images are restored from the compressed signal data.

Abstract: When an image is displayed on a display device on the basis of image data, a blank region is formed around the image. A background color is displayed on the blank region. The background color to be displayed on the blank region is set so that its color temperature nearly matches that of a white paper sheet placed under desired illumination light. In this manner, the color tone of a preview image can be adjusted to match that of the original image with high precision.

Abstract: An image data coding and/or decoding system according to the present invention has an input terminal for inputting an image data signal, a screen-area determining section for determining the area of the produced screen by analyzing the image data signal, a code amount assigning section for assignment of the screen on the basis of the determined results from the screen-area determining section, and a coding section for coding the image data signal inputted using the control signal from the code amount assigning control section.

Abstract: A data encoding method including an encoding step of encoding data using wavelet transform and a multiplexing/transmitting step of appending the information on encoding used for decoding on the decoder side to a bitstream of data encoded using the wavelet transform for transmitting the resulting information. This enables switching of filters depending on the picture or the computational capability that can be furnished by an apparatus and desirable initial setting depending on the input picture or bitrate to realize good picture quality.

Abstract: A digitized image is encoded by detecting edges in the image, encoding the position and sharpness of the detected edges, filtering the image by a low-pass filter to generate a low-frequency image, and encoding the low-frequency image. A digitized image encoded in this way is reconstructed by generating a horizontal edge image and a vertical edge image from the encoded edge position and sharpness information, synthesizing a pair of high-frequency images by filtering the horizontal and vertical edge images with an edge synthesis filter, decoding the low-frequency image, and performing an inverse wavelet transform on the decoded low-frequency image and the high-frequency images.

Abstract: A decoding method includes using a plurality of first bitstreams that are obtained by dividing a main bitstream with a hierarchical structure as inputs, successively arranging the plurality of first bitstreams and arranging selected second bitstreams before first hierarchical information of specified bitstreams among bitstreams constituting a specified hierarchy in the main bistream. Each second bitstream includes at least one of a plurality of codes including portions of the second bitstreams that do not corresond to specified code tables that are used for decoding bistreams, thereby forming a third bitstream.

Abstract: It is an object of the present invention to appropriately extract areas for character recognition from a color image. It is another object of the present invention to separate and extract characters from a background color in a color image if the background of the manuscript is not white and if the characters are printed in a portion having a color that is not commonly used all over the image. To achieve these objects, this invention binarizes an input color image in a plurality of stages and extracts area from binary images obtained in each stage to enable areas and text sections to be appropriately extracted despite the unknown colors of the characters and background contained in the input color image.

Abstract: A preprocessor for processing sample data, particularly digital video data, to improve lossless sliding window type Lempel-Ziv compression of the data. Sliding window Lempel-Ziv compression is improved by transposing the multiple bit per pixel data samples before compression so that the relatively repetitive higher order bits of successive pixels are compressed separately from the relatively volatile lower order bits of the successive pixels. The transposition is particularly suited for bit plane configured frame buffers in that compression and decompression grouping is readily performed by the manipulation of data within the individual bit planes.

Abstract: In a method and a device for transforming a stream of digital numbers, the correlation between successive numbers is utilized in order to obtain a new stream having a very low correlation between the numbers, whereby the sequence of numbers can be coded much more efficiently from a compression point of view. The numbers are for this purpose coded with the difference between a predicted number (s′(i)) and the actual number (s(i)) taking into account that the sequence does not need to be possible to decode in reverse order. The non-reversible codes can also be applied in lossy data compression schemes. Such schemes can change in accordance with the currently available bandwidth in order to obtain a graceful degradation and optimal bandwidth usage when the compressed data stream is transmitted over a channel having a time varying bandwidth. A general method and device for reversible coding are also provided.

Abstract: A color space structure and quantizing method is disclosed. Upon conversion from the RGB color space into HSV color space, a difference value S′ (S′=max−min) is obtained by varying the maximum value of the saturation S in accordance with the value V resulting in a HS′V color space where the difference value S′ forms one axis of the color coordinate, such that all of color areas are evenly distributed and the variation of color is uniformly displayed.

Abstract: A method of rotating an input image matrix of pixel data 180° to form an output image matrix of pixel data using a computer. The input image matrix is divided into pre-rotated bands of image pixels. Groups of pixels of a first pre-rotated band are accessed beginning at a bottom end of the first band and ending at a top end of the first band. The order of the pixels within each group of pixels of the first band is then reversed. The groups of reordered pixels are written to a band memory to form a rotated band of pixel data. In the rotated band of pixel data, the order of the groups of pixels of the rotated band is in reverse order to the order of the groups of pixels in the first band. The steps of accessing, reversing, and writing steps are repeated for the other bands of image pixels. Finally, the rotated bands are combined in reverse order of the pre-rotated bands to form the output image matrix. Optionally, the bands are concurrently reordered and compressed.

Abstract: Data representing a compressed document, referred to as a smart document, is produced from a document page composed of an array of pixel signals having values representative of gray scale. The system initially subdivides the pixel signals of the document page into a matrix of blocks, and classifies blocks as active or non-active. The document page is segmented into macroblocks (segments) by grouping one or more adjacent active blocks. One or more regions of adjacent non-active blocks are then located and the prevalent value of pixel signals in each region is determined to provide background data. The macroblocks are classified as first or second macroblock types based upon the values of the pixel signals in each macroblock. A bit-map is produced representing the blocks in the matrix of the first macroblock type. The pixel signals in the blocks represented in the map are thresholded into a binary representation to provide a binary image.

Abstract: An image coding apparatus and method code an object image by separating the object image into a shape representing the outline of the object image and a texture representing the pixel values of the object image. The coded object image is decoded by an image decoding apparatus and method adapted for the image coding apparatus and method. The image decoding apparatus and method generate a shape code by coding the shape in predetermined units, generate a texture code by coding the texture in predetermined units, and generate a synchronization code with respect to the shape code for each predetermined unit and the texture code for each predetermined unit. The generated synchronization code is added to the shape code for each predetermined unit and the texture code for each predetermined unit, which thus provides codes enabling restoration from an erroneous condition.

Abstract: An image scanning technique of the present invention shortens the time required for reading images of a plurality of originals set on an original tray. The positions of a lens 18 and a line of CCDs 20 are adjusted, so as to enable a scanning range of the line of CCDs 20 in a primary scanning direction to cover a plurality of originals. A first shooting range Z1 of the line of CCDs 20 covers four trimming areas Tr1,Tr2, Tr5, and Tr6. The procedure of the image scanning technique first reads white reference data of a white reference plate in the first shooting range Z1, then scans the four trimming areas Tr1, Tr2, Tr5, and Tr6 while fixing the shooting range to the first shooting range Z1, and carries out shading correction to correct image data obtained by the scan with the white reference data. This structure requires the process of scanning the white reference plate and updating the white reference data only once for correcting the image data of the plurality of originals.

Abstract: An apparatus and method for efficiently filtering or otherwise processing digital color image data. The invention may be implemented in hardware, firmware or software. In one embodiment, the green color signal is filtered while the blue and red color signal are not filtered. This results in less filtering circuitry and processing time, while retaining the sharpness of the unfiltered signals. Since the human eye is more sensitive to the color green, filtering this color produces the greatest amount of noise reduction per color. Alternative color and filtering arrangements are also disclosed as is file conversion logic.

Abstract: An apparatus and a concomitant method is disclosed for encoding wavelet trees in a wavelet-based coding technique, which the use of band dependent tables to address specific bands of the wavelet tree addresses.

Abstract: An image coding apparatus inputs pixel data of a part image of high resolution. An upper layer coding portion (101), a second shape data generating portion (102), and a second shape data coding portion (103) perform coding of shape data and pixel data in the upper layer. A down sampling portion (104) generates pixel data of low resolution. A lower layer coding portion (105), a first shape data generating portion (106), and a first shape data coding portion (107) code shape data and pixel data in the lower layer.

Abstract: A method and apparatus for encoding a digital image is disclosed. A differences is calculated between a first sample from a current scan line and a corresponding second sample from a previous scan line. A quantization table level is selected from a quantization table that at least one level, and information identifying the selected level is placed into an information stream. A quantizer is selected from the quantization table level based on the calculated difference and information corresponding to the selected quantizer is placed into the information stream.