Abstract: An image reading apparatus includes a carrying unit for carrying a sheet original and a book original to a reading position, an original urging member including a reference member, closed when a sheet original is carried by the carrying unit and opened when a book original is carried by the carrying member, a reading unit for reading an image of an original carried to the reading position and the reference member of the original urging member in a closed state, and a correcting unit for correcting nonuniformity of an image signal obtained by reading an original image on the basis of a reference signal obtained by reading the reference number. When the original urging member is open, the correcting unit corrects nonuniformity of an image signal on the basis of the reference signal used upon reading of a previous original image.

Abstract: A color image processor inputs the color image data of one color-separated picture element, weights the input color image data, reduces the amount of information of the weighted color image data and outputs the reduced color image data.

Abstract: An image reduction system which reduces binary level images is disclosed. In the system, a reduction pixel value is determined by using, as reference pixels for a filter operation: a plurality of surrounding pixels including an object pixel to be reduced; and reduced pixels, from among pixels which have already been reduced, said reduced pixels being at least a reduced pixel located before the pixel to be determined: a reduced pixel, located on the preceding line, which lies directly above the pixel to be determined; and a reduced pixel before said reduced pixel located on the preceding line.When a pixel referenced during the filter operation is included in a specific pattern, an exception process for correcting binary level results is provided.

Abstract: An image signal restoring device is arranged to input a digital image signal, to output a digital image signal which has been delayed for a first period of time when the input digital image signal is delayed for the first period of time, and to output a digital image signal obtained by adding together the input digital image signal and a digital image signal which has been delayed for a second period of time when the input digital image is delayed for the second period of time. The arrangement enables the device to stably restore the image signal without any adjustment, etc.

Abstract: An image encoding apparatus includes a conversion circuit for converting binary image data to be encoded into multi-value image data, a sampling circuit for sub-sampling the multi-value image data from the conversion circuit, a binary-encoding circuit for binary-encoding the multi-value image data sub-sampled by the sampling circuit, and an encoding circuit for encoding binary image data from the binary-encoding circuit. The binary-encoding circuit binary-encodes the multi-value image data while diffusing an error generated upon binary-encoding to surrounding pixels.

Abstract: A technique for detecting erroneous pixels in image data output by a scanner. A first aspect of the technique is to test for the existence of an erroneous gap by comparing the values of selected pixels to one of several predetermined patterns. A potential gap is identified wherever a center pixel of a background value is located between two pixels of a foreground value. A second aspect of the technique tests for the existence of an erroneous gap by examining the values of pixels surrounding the potential gap more completely. In particular, the relative sizes of two line features on either side of the potential gap are determined by tracing the feature's perimeters to locate terminus pixels. If the terminus pixels are farther apart than a predetermined distance, it is concluded that a gap exists. The technique can be easily adapted for rapid execution on both bitmap and run encoded image data.

Abstract: A image processing method smooths edges. An image is represented as pixels. A plurality of groups of pixels are formed. A median is calculated for each group, and a median of medians is calculated. Pixels in groups are altered according to the median of medians to generate a smooth image.

Abstract: A method for controlling a data terminal equipment coupled to a network via a line and coupled to a center apparatus via the line and the network. A plurality of tone signals sent from the center apparatus and having mutually different frequencies are received. The levels of the tone signals are detected. The characteristic of the line is judged on the basis of the levels of the tone signals. A suitable equalizing characteristic most suitable for the characteristic of the line is selected from among a plurality of predetermined equalizing characteristics compensating for possible characteristics of the line. There is also provided a data terminal equipment using the above-mentioned method.

Abstract: In a picture processing apparatus, respective results of subtraction calculation between the relevant pixel and the reference pixels are obtained by a subtraction arithmetic circuit. The resultant differences are converted nonlinearly by a nonlinear conversion circuit, and thereafter a summation calculation of these resultant differences are performed by a first addition arithmetic circuit. The obtained result is added to data of the relevant pixel by a second addition arithmetic circuit; thereby achieving MTF correction. By adequately selecting the input-output characteristic of the nonlinear conversion circuit, a stable contour line enhancement is achievable even when noise is present in the picture signal.

Abstract: An image data processor including various subprocessors arranged in a pipeline for carrying out functions such as pixel normalization, background suppression, spot and void removal, image scaling, and size detection.

Abstract: The image processing apparatus of the present invention determines the number of surrounding pixels to be averaged and their locations, determines a weighting coefficient based on the density and contrast levels of an input image data derived from a continuous tone image, and performs an averaging operation on the input image signal by performing a weighting operation using the averaged result of the surrounding pixels, the input image data, and the weighting coefficient. Therefore, the image processing apparatus of the present invention is capable of reducing the noise level over a wide range of image types, from shadow regions with high density. Further to highlight regions with low density, and images reproduced by this apparatus do not exhibit a deterioration of the sharpness of image boundaries in the high density regions, images characterized by a gradual change in the density level do not turn out having an unnatural quality.

Abstract: A video image processor for generating an enhanced image of data based upon input gray scale picture element values of image data of a document background and printed information contained thereon generates a histogram of the gray scale picture element values for each tile of image data for an area of the document representing the frequency of occurrence of picture elements of a particular gray scale value. A correlator processes each histogram to determine a back reference level and a white reference level for each tile. Normalization factors are calculated based upon the black reference level and the white reference level. The input gray scale picture element values for each tile of the image data associated with the normalization factors of each tile are normalized based upon the normalization factors for each tile and correlated to generate a normalized and correlated representation of the image data.

Abstract: An image processing device for reading an original image by shifting in a sub-scanning direction image sensors provided in a main scanning direction to serially output image signals read, includes line memories for storing image signals by a plurality of lines in the sub-scanning direction, read for every line by the image sensors, an output device for outputting in parallel the image signals from the line memories, and an edge emphasizing device for carrying out edge emphasis in accordance with the image signals outputted by the output device in response to signals externally applied.

Abstract: A method for converting a first image of a first resolution to a second image of a second resolution comprises steps of detecting a predetermined pattern in the first image, the predetermined pattern contains a stepped boundary and includes at least a central picture element having a first content and formed by the first picture element, the central picture element is defined by a first edge extending in a first direction and a second edge extending in a second direction in corresponding to the step, dividing the central picture element into a first sub-picture element and a second sub-picture element each having a same size, and inverting the content of one of the first and second sub-picture elements depending on the detected predetermined pattern.

Abstract: A video printer device is disclosed which is capable of printing out a high quality still image by subjecting image data obtained from a continuous video signal such as a television signal or the like, to noise processing and tone processing to improve the quality of the same. Upon subjecting said video signal to the noise and tone processings, a processed image can be displayed on a screen of a monitor, and checked and corrected on the same screen on real time.

Abstract: A digital halftoning method and apparatus with error diffusion reduces visibly discernible artifacts. In the error diffusion method and apparatus, a range function provides random factors which are used to spread erros to neighboring pixels.

Abstract: An image signal (Sij) from an original which gears image information is processed by generating a new image signal (S'ij) from the image signal (Sij). It is first determined whether the configuration of the distribution of the image signal (Sij) at a point of interest (i, j) is upwardly convex, or a downwardly convex, or otherwise. An image emphasis signal (S.sub.G ij) larger than the image signal (Sij) at the point of interest (i, j) is employed as the new image signal (S'ij) if the configuration is upwardly convex. An image emphasis signal (S.sub.L ij) smaller than the image signal (Sij) at the point of interest (i, j) is employed as the new image signal (S'ij) if the configuration is downwardly convex. The original image signal (Sij) or an unsharp signal (Uij), generated from the new image signal (S'ij), is employed as the new image signal (S'ij) if the configuration is otherwise.

Abstract: Apparatus, and accompanying methods, for determining appropriate sampling points located throughout a scanned microfilmed bit-mapped "data strip" in order to properly extract the values of stored data bits therefrom. Each data bit is formed of a contiguous group of one or more pixels in the data strip. Specifically, my technique involves parsing the data strip into successive vertical strips that each has successive rows of pixels, determining inter-row and inter-pixel differential intensity values for each vertical strip, and defining vertical line addresses and horizontal pixel addresses in each of the strips as a function of the pixel positions of the inter-row and inter-pixel differential intensity values associated therewith. The individual pixels in each vertical strip, which are situated at the horizontal pixel addresses and which lie on those rows in that vertical strip specified by the vertical line addresses, are sampled in order to yield sampled pixel data.

Abstract: A pseudo center weighted local variance in the neighborhood of an image pixel determines the amplification factor multiplying the difference between the image pixel and its blurred counterpart before it is combined with the original image. The amplification factor is computed for each pixel in the image, and varies from a minimum value of about -1 when the center weighted variance is at a minimum value to some maximum value when the center weighted variance reaches a maximum value. The pseudo center weighted variance is computed by convolving the local neighborhood surrounding each image pixel with a kernel of center weights having a maximum value at the center pixel. The pseudo center weighted variance is the difference between the center weighted mean of the source of the local neighborhood of image pixels and the square of the center weighted mean.

Abstract: A facsimile apparatus according to the present invention is arranged to evaluate the density of an original image to be transmitted and/or the resolution of a communication installed on the reception side, determine a resolution for transmission on the basis of the result of the evaluation, and transmit the image at such a resolution. Accordingly, it is possible to transmit the image at an optimum resolution which corresponds to the resolution of the communication device installed on the reception side and/or the density of the original image.

Abstract: An image processing apparatus for processing an image signal, comprising a clock for generating a periodical clock signal, a pattern signal generator for generating 2N (where N is a positive integer) pattern signals, each of the pattern signals having a constant wave-form, a wave length of 2N times longer than that of the periodical clock signal and a phase difference 360/2N relative to another one of the pattern signals, a comparator for comparing the pattern signals with the image signal and for generating 2N of comparison signals, and a composition generator for combining said 2N comparison signals and for generating a pulse-duration modulated signal from the combined 2N comparison signals.

Abstract: An image signal representing image information containing a periodic pattern is processed before it is broken up into halftone dots. First, the image information is averaged to generate an unsharpness signal, and then the unsharpness signal is processed for edge sharpness to generate a sharpness signal. Thereafter, a halftone-dot image is generated from the sharpness signal. More specifically, the sharpness signal Sij* is generated from a first unsharpness signal Uij which is produced by averaging the image information and a second unsharpness signal Uij which is produced by averaging the first unsharpness signal Uij, according to the equation:Sij*=Uij+K.multidot.(Uij-Uij)wherei=1, 2, . . . n,j=1,2, . . . n, andK: sharpness parameter.The halftone-dot image thus reproduced is sharp and free of a moire pattern which would otherwise result from the periodic pattern.

Abstract: A facsimile apparatus including image data conversion unit for converting image data corresponding to an image to be printed in such a manner that two adjacent dots on a main scanning line of the image data are converted into one dot a smoothing unit connected to the conversion unit for modifying converted image data in such a manner that, if a pattern of a region formed by a predetermined number of converted dots coincides with a predetermined pattern, the converted image data is changed to have a pattern corresponding to the predetermined pattern in the region; and selection unit connected to the image data conversion unit and the smoothing unit and adapted to select an output of the image data conversion unit as printing data if it is detected that the image data has been transmitted in a fine mode, and select an output of the smoothing unit as printing data if it is detected that the image data has been transmitted in a standard mode.

Abstract: According to an image signal processing apparatus in accordance with the present invention, an input signal is converted to a digital image signal and then the digital image signal is cyclicly shifted. Therefore, a desired signal component can be collected on a first or second level side. Therefore, a signal can be divided into bilevels in reference to one threshold value or it can be divided into multiple levels in reference to a plurality of threshold values. As a result, it is possible to precisely extract contours of the image signal even if there is a small density difference between a background signal and an information signal. In addition, a background can be converted between white and black.

Abstract: An error diffusion process for eliminating visually-perceptible artifacts in images reproduced by digital halftone printing.

Abstract: An image processing apparatus comprises an unsharp signal generating means for processing image signals S obtained from continuous-tone images for average so as to generate unsharp signals U, a weighted parameter generating means for generating weighted parameters P and Q according to the level of the image signals S and the level of the unsharp signals U and an image signal producing means for producing an image signal T according to the following equation:T=P.multidot.U+Q.multidot.SwhereS is an image signal, U is an unsharp signal andP and Q are weighted parameters.The unsharp signal generating means comprises an addition averaging circuit for adding the image signals S corresponding to an even number of pixels arranged to form a continuous-tone image to be scanned in a main scanning direction and for processing the added signals for average, thereby to generate unsharp signals U.

Abstract: A new image (S'ij) is generated from an image signal (Sij) by determining whether the configuration of the distribution of the image signal (Sij) at a point of interest (i, j) is upwardly convex, or a downwardly convex, or otherwise, employing, as the new image signal (S'ij), the original image signal (Sij) at the point of interest (i, j) if the configuration is upwardly convex or downwardly convex, and employing, as the new image signal (S'ij), an unsharp signal (Uij) if the configuration is otherwise. A differential signal (Sij-Uij), or an absolute signal .vertline.Sij Uij.vertline., or a square signal ((Sij-Uij).sup.2), or a Laplacian signal (.gradient..sup.2 Sij) is compared with a threshold signal (T) to determine whether the configuration of the distribution of the image signal (Sij) at a point of interest (i, j) is upwardly convex, or a downwardly convex, or otherwise.

Abstract: A method of dynamically adjusting the threshold level of an error diffusion algorithm to selectively control the amount of edge enhancement introduced into the encoded output. The threshold level is selectively modified on a pixel by pixel basis and may be used to increase or decrease the edge enhancement of the output digital image, thus, more closely representing the original detail and edge sharpness of the continuous tone input image.

Abstract: An image amending method for amending a signal indicative of an image which was photoelectrically converted comprises: classifying pixels which constitute a digital image into extraordinary pixels which need to be amended and ordinary pixels which do not need to be amended; setting an attention pixel; when the attention pixel is an extraordinary pixel, amending the data thereof by setting data of a peripheral ordinary pixel (other than pixels adjacent at the positions adjacent to the attention pixel in the upper, lower, left, and right directions) as amendment data for the extraordinary attention pixel; and, preferably, limiting a range of the peripheral pixels which are substituted for the extraordinary attention pixel. When no ordinary pixel exists in this range, in the amending step, the data of a previously amended peripheral pixel is set as the data of the attention pixel. With this method, a person without much experience can easily satisfactorily amend the image.

Abstract: Apparatus for converting multilevel video images into a bilevel image having an accurate rendition of the original grayscale of the image. The apparatus performs enhanced preservation of edge information in the image when using error diffusion techniques.

Abstract: More efficent encoding/decoding in decomposing and recomposing a high resolution image is obtained by employing a unique pixel cluster arrangement. The pixel clusters of an image are classified as one of a plurality of classifications. A unique encoding/decoding technique is assigned to each classification. In one embodiment, a cluster including at least one high resolution pixel to be recomposed from a corresponding low resolution pixel which is a so-called exception to general prediction rules is classified as a first classification. A cluster including no pixels which are exceptions is classified as a second classification. Supplemental information is encoded/decoded for all pixels in a cluster classified as the first classification. Pixels in the cluster classified as the second classification are encoded/decoded according to the general prediction rules.

Abstract: The image data processing unit supplies the image data from the memory to the look-up table, and resupplies output data from the look-up table to the look-up table by feeding it back to the input side of the look-up table. When supplying the fed-back data to the look-up table, the data once subjected to image processing is again processed by carrying out image conversion on the basis of a differently configured look-up table, by switching over the content in the look-up table from the previous content on the basis of pre-stored information. The data subjected to the desired data conversion by the look-up table is supplied to the display unit via a DA converter.

Abstract: The invented method scales a graphics image by recognizing under what resolution the image was created, identifying the resolution of the printer that will actually print the image, calculating a convenient virtual resolution, approximating, on a pixel-by-pixel basis, using the virtual resolution, how many new pixels are required to emulate each existing pixel and then storing the new pixels in memory or printing them.

Abstract: A video signal processing apparatus for converting an input analog video signal, including a variable-density image signal and a two-state image signal, into an output analog video signal whose number of scanning lines is increased without degrading the visibility of the two-state image; wherein the input video signal is separated into variable-density image data and two-state image data; then, a portion of the variable-density image data from which the two-state image data is removed, is replaced with a variable-density image data portion immediately before the beginning of the two-state image data; then, the variable-density image data and the two-state image data are stored separately in a memory; then, a general analog-mode enlarge interpolation processing, such as a linear interpolation processing, is performed on the variable-density image data; then, a two-state mode enlarge interpolation processing is performed 10 on the two-state image data; and then, the variable-density image data and the two-state

Abstract: There is provided an improvement on the error dispersion method for binary digitizing of an image, in which an area of plural pixels is digitzed, and the error into the digitizing is dispersed in a neighboring area of plural pixels. In the latter area the digitization is conducted according to the image data of plural pixels and the error data dispersed into this area.

Abstract: An image processor in which a high-frequency component of image signals is diminished, and a density value of each of the "diminished" image signals is compared with a first reference value in a first comparator. A first classifier is provided for classifying the image signals into a character image and a tonal image based on a signal output from the first comparator. A length or an area of an image signal classified into the tonal image is measured, and a second comparator is provided for comparing the length or area of a measured image signal measured with a second reference value corresponding to a reference length or a reference area. A second classifier is provided for further classifying an image signal below the second reference value from the second comparator into an image signal of the character image.

Abstract: Detail enhancement is achieved by producing an enhanced image signal (ES) on the basis of a sharp signal (S), a middle signal (M) and an unsharp signal (U). The sharp signal represents density of a pixel, the middle signal represents weighted mean density of a first area larger than a pixel, and the unsharp signal represents weighted mean density of a second area larger than the first area. Three differential signals (S-M, S-U, M-U) are obtained and multiplied by respective coefficients to become three enhancements signals. The enhanced image signal is obtained by adding the sharp signal and at least one of the three enhancement signals so that the detail enhancement is achieved at a middle range of spatial frequency.

Abstract: There is disclosed an electrophotographic printer for projecting light from light source emitted according to image data onto a photoconductive body performing a mechanical scan operation in a subscan direction so as to form an image of the image data thereon, and for printing the image on a piece of printing paper using the electrophotographic process. In the electrophotographic printer, the light source comprises plural light emitting devices such as LEDs aligned in a main scan direction perpendicular to the subscan direction, and each light emitting device has a light output opening elongated in the subscan direction. Image data received from an external unit are once stored in an image memory, and the image data read therefrom are Fourier transformed.

Abstract: A method for graving printing forms using rastered masters by means of a scanning system which can be adjusted in focus. The signal supplied by the scanner after processing in an electronic computer controls a graving system so as to scan rastered originals. The scanning system is placed out of focus and the loss of image information caused by placing it out-of-focus is compensated by means of an electronic out-of-focus mask.

Abstract: An original image is read with an image reader for each pixel, whereby color component signals (Yi, Mi, Ci, Ki) expressing the original image are obtained. A sharp signal generator extracts the gray component from the combination of the color component signals, to output the gray component as a sharp signal (S.sub.O). The difference between the sharp signal (S.sub.O) and an unsharp signal (U) is linearly combined with the color component signals, to thereby give sharpness-enhanced signals (ES.sub.Y, ES.sub.M, ES.sub.C, ES.sub.K).

Abstract: An image processing apparatus has a function of enlarging or reducing an image which is processed by a certain magnification. A modulation transfer function (MTF) correction circuit is provided in the image processing apparatus and the correction quantity or filter characteristic of this MTF correction circuit is automatically changed depending on a change in the magnification.

Abstract: The invention relates to the making of reproductions of microfilm images which are scanned line-by-line using photoelectronic devices. The subsequent generation of images are reproduced onto photosensitive material line-by-line. By processing the video signal generated by scanning the first or original image, a series of parameters are produced which are stored either on the film or in a separate location. The second generation image is electronically scanned and the video signal processed to provide a second series of parameters. The first and second series of parameters are compared to provide an adjustment signal. The adjustment signal is then used to change or alter the second video signal prior to it being used to electronically reproduce the second generation image on film. The stored series of video parameters are used to produce subsequent generations of film images in a like manner.

Abstract: An image signal processing method and apparatus includes elongated picture elements in a CCD linear image sensor to provide improved resolution. The outputs of the picture elements are converted into digital signals and are processed to compensate for the variance in photosensitivity of each of the individual picture elements.

Abstract: In order to correct the swathe related banding effect often seen on swathe-scanned imagers a vertical smoothing function separates out artifact detail from the idealized image and derives, from this, proportional corrections for each channel within a swathe. In cases where the artifact varies from swathe to swathe a second algorithm is used to obtain correction values for each line of the image.

Abstract: A color image processing device includinga reader for reading an original image for each area containing a predetermined number of pixels of the original image and color-separating the read area into red, green and blue components,a character area detector for detecting whether or not the area read by the reader is a character area constituting a part of a character in the original image for each of the red, green and blue components, anda black character area determinator adapted to determine the area read by the reader to be a black character area constituting a part of a black character in the original image if said area is detected to be the character area for all of the red, green and blue components by the character area detector.

Abstract: A method of generating a composite image on a record medium at a first resolution resulting from two subsidiary images defined by pixels at a second resolution lower than the first. The method comprises generating an array of control data at the second resolution, the control data indicating the relative locations of the subsidiary images in the composite image at the first and second resolutions, generating data defining the composite image at the second resolution under the control of the control data, interpolating the second resolution composite image up to the first resolution, the relative locations of the subsidiary images at the first resolution being determined in accordance with the control data, and causing the first resolution composite image to be recorded on the record medium.

Abstract: A system and method of modifying pixels supplied to the system that a multiple level signals for a digitized image wherein a moving pixel window with a center pixel, D.sub.c, is used from which the annular means, m.sub.a, of the center pixel (the mean of the 2.sup.N pixel values of the window surrounding the center pixel, where N is an integer of 1 or more) is determined with the center pixel and selected pixels surrounding the center pixel, D.sub.c, are used to determine a measure of deviation (center deviation, .sigma..sub.c) of the center pixel relative to the center pixel that is used to obtain a modification gain, f(.sigma..sub.c,C.sub.g). The center pixel, D.sub.c, its annular mean, m.sub.a, and its modification gain, f(.sigma..sub.c,C.sub.g) or F'(.sigma..sub.c,C.sub.g) are used to obtain a modified center pixel value, D.sub.c 40 , in accordance with one of the following equations that are of the form for an algorithm for determining the unsharp marking filter value for an image pixel:D.sub.c '=[f(.

Abstract: A document scanner generates an 8-bit binary word for each picture element (PEL) of a document. One of a group of 256 different binary words is thereby generated in accordance with the image/background content of each document PEL. These scan words vary in magnitude from hexadecimal "00" to "FF", representing a PEL containing only white background, or representing a PEL containing only the most dense black portion of the document's image, respectively. An intensity and/or contrast look-up table memory element, or a computation means, each having 256 addressable locations or inputs, is addressed using the scan words. Each storage location or input is addressed by one of the 256 possible document PEL words. The stored content of each storage location in the look-up table memory element, or the value that is computed by the computation means, comprises an enhanced 8-bit binary word that varies as a function of user selected image intensity and/or contrast enhancement.

Abstract: An image recording apparatus includes a first recording unit, a second recording unit, and a control unit. The first recording unit scans an original image and records an image on a recording medium. The first recording unit has a first operation mode for evening a surface of the recording medium. The second recording unit records an image on the recording medium. The second recording unit has a second operation mode for evening the surface of the recording medium. The control unit controls the first and second recording units. The control unit controls the first recording unit so as to even the surface of the recording medium in the first operation mode at a start of image recording.

Abstract: A graded facsimile image signal coding system is disclosed which is provided with means for distributing a multi-graded facsimile picture signal, represented by 2.sup.n gradation levels, into n bit planes corresponding to n digits; initial encoding means for detecting, from picture elements forming each bit plane, picture elements at intervals of .DELTA.X picture elements on every .DELTA.Y-th line and encoding the detected picture elements; and additional coding means for .[.further .]. coding each one of .[.said encoded.]. .Iadd.picture elements except said detected .Iaddend.picture elements with reference to encoded four picture elements positioned around said one picture element to be coded.