Abstract: Disclosed are an image coding method and apparatus for coding digital image data in a highly efficient manner, and to an image decoding method and apparatus for decoding the data thus coded. Each image signal constituting the image data is partitioned into a plurality of pixel blocks, and coding of each of the image signals is performed in block units. A plurality of items of coded data obtained by such coding are gathered together to form a block (a re-sync block) corresponding to each image signal. A plurality of the re-sync blocks corresponding to the image signals of an image area of the original image data are sequentially combined, boundary-line information is inserted between mutually adjacent re-sync blocks, and an error correction code is attached to form a code for transmission. In the apparatus for receiving this code, the code is decoded into the original image data by partitioning the code into re-sync blocks and performing decoding and interpolation in re-sync block units.

Abstract: In data processing wherein image data are processed by dividing them into blocks, a chroma data W is obtained from the color difference data W.sub.R and W.sub.B, and the color difference data W.sub.R and W.sub.B are corrected according to an amplitude of the chroma data W. For example, if the chroma W is smaller than a prescribed threshold value, the color difference data W.sub.R and W.sub.B are set as zero. Then, the so-called block distortion can be prevented. The degree of the correction may depend on the amplitude of the chroma data W. On the other hand, DC coefficients of discrete cosine transform coefficients of adjacent blocks are compared with each other. When the DC coefficients are different from each other, block distortion occurs if they represent a same image. Then, if differences of DC coefficients of discrete cosine transform coefficients of adjacent blocks are small with each other, the DC coefficients are corrected to tend to have similar values.

Abstract: A color image communication apparatus can switch between a copy mode and a communication mode. In the communication mode, color space standardization conversion of objective color image data is performed, while in the copying mode, color space standardization conversion of the objective image data is not performed.

Abstract: An image transmission apparatus includes a color codec section for performing color image coding of a color image, a run-length codec section for performing run-length coding of a monochrome image, and a switching unit for arbitrarily switching the codec sections and to perform coding in units of pages in one communication cycle depending on whether each page is a color image or a monochrome image. Whether each page is constituted by a color image or a monochrome image is set in advance, and corresponding information is stored in a memory. Coding is performed by a coding scheme set for each page, and the coded data is transmitted. Alternatively, coded data obtained by both the codec sections and are stored in a hard disk, and the data coded by a coding scheme which an apparatus at the other end of a communication line can handle is read out and transmitted.

Abstract: A method and apparatus for image processing, in which coded recording information is developed into bit image data in units of given areas. Each area has a size which is an integer multiple of the height of the record head. In addition, the recording information can be managed in units of record heads, and coloring agents, thereby reducing recording processing time. Further, unnecessary initialization is avoided because it is first checked to determine if any information is present within the width of the corresponding recording head, and only initializes if necessary.

Abstract: An apparatus having the G4 method and the JPEG method allows for the selection of standard resolution (200 dpi.times.200 dp) or precision resolution (400 dpi.times.400 dpi) by using a resolution selection key of operation unit 26 in order to improve the operativity and extend the breadth of selection of image quality. For each selection of standard resolution or precision resolution, the resolution and code information for designating quantization table for use with JPEG are stored in RAM 16, with its memory area being backed up by a battery.

Abstract: It is provided an image communication apparatus which comprises multi-level generation section for generating multi-level data from received image data, color conversion section for color-converting the multi-level data from the multi-level generation section, and setting section for setting a single color mode, in which the received image data is dealt with as single color data irrespective of the color conversion section, when it is determined by communication protocol that the communication mode is the single color mode, so as to ensure satisfactory communication even with a single color image.

Abstract: A gray pixel encoding scheme is used in combination with a halftoner and an imager to produce halftoned images. A halftoner and an imager can be totally separate because the gray pixel encoding allows the imager to decode them at any time. The encoded gray pixels require less bandwidth than explicit gray pixels and can be decoded by the imager in an optimal fashion for the characteristics of the specific printer being used. An imager produces a small partial pixel within a spot boundary. The subpixel produced is called a gray pixel. The gray pixel is allowed to grow from a zero width to a full spot width and is allowed to start anywhere within the spot. The pixel codes describe the starting positions of the gray pixels, the locations of the gray pixels within the spot, and the gray pixel width required. The imager uses the encoded gray pixel from the halftoner to produce a final halftoned image.

Abstract: An image processing apparatus receives compressed color image data and/or non-compressed color image data for each pixel and discriminates whether the received color image data is compressed or non-compressed color image data. The received color image data is processed and outputted. The color image data may be processed so that compressed image color data is expanded when the received color image data is discriminated as compressed color image data and is half-tone processed when the received color image data is discriminated as non-compressed color image data. The received color image data may be stored in a common memory represented by the same kind of plural color components and the frame data format of the compressed image data may be converted.

Abstract: An image editor for an image processing system has a predefined set of system colors. Color pixel color index values for an image to be edited are stored in an image buffer. A color lookup register bank stores color values in respective registers for a predefined set of system colors. Each buffer index value corresponds to a lookup register having the specified color value. The image is thus displayed by indexing the image pixels to the lookup register bank for the color signal inputs to the display. A mouse is used to designate displayed colors that a user desires to modify in a region of the displayed image. Pixel position data corresponding to the designated colors is detected and hue, saturation and brightness (HSB) values are determined from the stored color values for the designated image pixels. A minimum range of values is determined for each of the HSB variables.

Abstract: A high speed color video printer for printing video signals representative of color images including a data converter comprising an internal memory storing one frame of video data representative of color images in rows and columns, for reading and writing each column of video data stored in the internal memory into a single line memory during vertical synchronization and equalization pulse intervals in each field period and enabling printing each column of video data stored in the line memory during remaining intervals of each field period. With the use of the data converter, columns of video data for each field period can be read and printed much quicker than the currently available video printers. The high speed color printer also includes a video monitor capable of enabling visual display of video data sequentially read from the internal memory in rows during the remaining intervals of each field period when the stored column unit of video data is being printed.

Abstract: An apparatus for processing image data. The apparatus converts analog green image data signals, analog red image data signals, and analog blue image data signals generated by imaging an object. The third image generation elements, representing the green image data, are arranged at positions shifted by a half pitch to the first and second image generation elements. The analog image data signals are converted into digital image data signals and are then compressed at a predetermined compression rate and stored in a recording medium by a storage means. In reproducing the image data, the recorded image data is read from the recording medium and expanded at a predetermined expansion rate to generate data substantially the same as the image data signals before compression. The expanded data is interpolated in a predetermined interpolation manner.

Abstract: The invention relates to an image processing apparatus having the function to encode or decode image data and discloses a technique in which an optimum encoding method is selected in accordance with the characteristics of an image and a high efficient encoding with little deterioration in image is executed.

Abstract: In a picture processing system for processing an input picture data signal representative of an original picture, such as a color natural picture, into a processed picture data signal, a detecting unit produces a difference picture data signal representative of a difference between the input picture data signal and an expanded picture data signal. The expended picture data signal is produced by a picture data expanding unit which expands a compressed picture data signal. The compressed picture data signal is produced by a first compressing section which compresses the input picture data signal. A converting unit converts the difference picture data signal into a binary picture data signal. A second compressing section compresses the binary picture data signal into a compressed binary picture data signal which is for use as the processed picture data signal.

Abstract: An image coding apparatus includes a color component. converter 2 for converting an input image signal 1 into predetermined color spaces which have been subdivided into independent color components, a segmenting circuit 4 for subdividing the converted image signals into predetermined image regions for the respective color components, a color information selecting circuit 9 for judging a condition of the color component of the input image based upon the components of the input image for each image region, and also a coding device 5 for performing a coding process with respect to the respective color components. In the color information selecting circuit 9, a judgement is made whether or not there is color information by comparing the pixel component of the pixel within the input image block with a predetermined threshold value. When it is judged that the input image block corresponds to the monochromatic information, the color difference component is not transferred or not stored.

Abstract: An apparatus and method to decompress a compressed color page image. Compressed image data and encoding data indicative of the type of encoding used are input into a decoder. The decoder decodes the data into an address. The address is used to select storage data which is used to select a color value or combination of color values, which are output as the decompressed image data.

Abstract: In a color facsimile apparatus, a color image file, or the like, an encoding system suitable for a color image to be transmitted is promptly selected and the image data is transmitted. The apparatus has: the color image input unit 20 to read a color image; a plurality of color image encode units 22 and 24 including the white/black image encoding; the storage units 23 and 25 to store the encode data; the means 28 and 29 for decoding the encode data; the means 32 for displaying the decoded image; and the protocol means 27 with an apparatus on the partner side.

Abstract: Image processing apparatus and method perform a predetermined compression processing for an input original. A compression processing method or a receiver of compressed data is changed in accordance with a color/black-and-white status discrimination for the input original, or is set manually.

Abstract: This invention relates to an image processing apparatus having a function of encoding or decoding image data and discloses a technique for extracting an image feature, especially a thin image portion of a specific color of an image, and for encoding the thin image portion with high efficiency to minimize degradation of image quality by selecting an appropriate encoding method.

Abstract: There is disclosed an apparatus for encoding, faithful to human visual characteristic, of color image data containing luminance information and color information in the unit of each block of predertermined size, by detecting the edge of the color image data in the block based on the luminance information, forming a code of a fixed length in response to the edge detection, encoding the luminance information and the color information into codes of different lengths according to the presence or absence of edge, and forming codes from the code of fixed length and codes of different lengths.

Abstract: The type of color image is identified on the basis of a distribution of color information for each color. A plurality of different types of data compression algorithms prepared beforehand are changed according to the results of the identification. Preferably, the difference between the maximum value and the minimum value of each picture element of respective color separation data of a color image is determined, and further, a histogram of frequency of color information obtained for each color is determined. On the basis of the histogram, the type of the color image is identified by the fact that whether or not the histogram contains a peak greater than a predetermined value or whether or not the deviation of the histogram is greater than a predetermined value.

Abstract: A coding apparatus divides digital image information into pixel blocks each having a size of m.times.n pixels, and subjects the image information to vector quantization in block units. The pixel blocks are orthogonally transformed and the characteristics and sequency components of the pixel blocks are detected. Each pixel block is divided into a plurality of sub-blocks in conformity with the detected sequency components. Respective ones of the plurality of divided and outputted sub-blocks are scalar-quantized into sub-vectors of a predetermined number of bits in conformity with the characteristics of the pixel blocks. Respective ones of the scalar-quantized values of the quantized sub-blocks are vector-quantized in conformity with the characteristics of the pixel blocks, these vector-quantized reproduction vector codes are combined and the result is subjected to further vector quantization.

Abstract: An image data processing apparatus includes a plurality of registers each of which outputs an output signal in accordance with a corresponding signal of a plurality of input coincidence signals derived from the input image data, the output signal indicating whether or not a corresponding register has a maximum count value, and each input coincidence signal indicating whether or not a corresponding pixel among neighborhood pixels of a target pixel of the input image data coincides with a corresponding dot among predetermined reference dots at given locations relative to the location of the target pixel in the input image data, and a state checking part for outputting a state signal indicating whether or not the output signal level of a first register having the maximum count value currently changes from the previous level by detecting the current output signal level of the first register in accordance with the input coincidence signals and in accordance with the output signals of the registers.

Abstract: There is provided an image encoding method in a facsimile apparatus or an image filing apparatus as an image communication apparatus. In this method, a color image signal which is expressed by a plurality of color component signals to be encoded is input, the input color image signal is converted into a bit stream signal, and the bit stream signal is encoded by the prediction encoding. A parameter for the prediction encoding is changed in accordance with the color image signal to be encoded. The encoding operation is executed adaptively to the color image signal to be encoded. By bit stream converting the binary color signal, the efficient encoding using the color correlation can be executed and an increase in data amount is prevented. By encoding the bit stream signal by using a dynamic arithmetic code, a binary color image can be efficiently encoded.

Abstract: At the time of registration, an image processing apparatus registers color information (R, G, B) from a host computer as permanently registered information in a buffer and as temporarily registered information in a table in accordance with a command from the host computer. The data registered in the buffer also is registered in the table and is used as internal data until initialization is performed. At the time of initialization, the data registered in the table is initialized with the exception of the data that has been registered from the buffer, if the command is indicative of a soft reset. In case of a hard reset, all of the data in the table is initialized.

Abstract: The image signal band compressing method employs a three-dimensional motion compensating technique, an intraframe and an interframe processes which are alternatively executed. The transfer rate of the intraframe to the interframe is set to 4:1 in a unit of fixed length. The intraframe process is defined such that the present frame image data is compressed in a variable length compressing manner by way of two-dimensional discrete coding transform. The interframe process is defined such that motion data is estimated by comparing the present frame and the preceding frame, the present frame is expected on the basis of the motion data and the difference data between the motion compensated image data and the present frame data.