Abstract: A document image scanner that converts scanned images for output as bilevel images is provided with a bilevel image filter. The bilevel image filter counts the number of continuous pattern elements in each direction, vertical, horizontal and diagonal, from a specific point and compares the results with a predetermined reference. Patterns falling below the reference value are regarded as resulting from background noise and are erased.

Abstract: Because of using as a light source a halogen lamp which is well stabilized in terms of both the quantity of light and the spectral ratio, it is unnecessary to read shading data whenever the reading of an image is initiated. The shading data can be read with a certain margin at the end of a copy job, when power is being given to an image reader or at given time intervals for making shading correction on the basis thereof. Reading the shading data can be carried out with a certain time margin without detriment to FCOT (First Copy Output Time) and CPM (Copy/Minute); enough time is allowed for acceptance of the shading data, so that data of a plurality of lines can be read and fault values, if any, can be removed therefrom. Therefore, the influences of dust, etc., even if present on the white reference plate, can be eliminated.

Abstract: A multi-chip linear image sensor for use in, for example, a facsimile machine or a photocopier comprises several chip image sensors, each including photosensors and an output amplifier. To correct for the offset error of the output amplifier caused by processing variations, each chip includes a circuit enabling the amplifier to be isolated, so that its output can be sampled independently of the image signal. To eliminate the offset error a correction circuit is provided as part of the video clamp circuit, for sampling the amplifier output and subtracting it from the subsequent image signals readout through the amplifier.

Abstract: Color image data of which background is removed is converted into monochrome data and noise in the monochrome data is roughly discriminated in a first noise discrimination process. At the same time, the color and density of an attentional pixel, information area including a character or a picture, and others are checked, according to which operations the resulting first noise discrimination data is corrected in a second noise discrimination process. Substitute data is created from the image data of which background is removed according to the first noise discrimination data, and the substitute data substitutes for a pixel regarded as noise in the second noise discrimination process to obtain an image from which noise is eliminated. With the above arrangement, noise having a high density and noise having a size greater than the scanning window are eliminated without receiving influence from the surrounding noise.

Abstract: An image processing apparatus performs an edge correction process for image signals of respective pixels sequentially inputted, each image signal having a density level corresponding to a pixel. An edge amount detector of the image processing apparatus calculates a difference between a density level of an image signal of a specified pixel predetermined from among the image signals and a product of a predetermined value and the sum of the density levels of peripheral pixels located at a predetermined distance from the specified pixel, and outputs a detection signal having a level of an edge amount of the calculated difference, and an edge amount convertor converts the edge amount of the detection signal into a converted edge amount in a predetermined manner, and outputs a conversion signal having level of the converted edge amount.

Abstract: An image processor has image processing logic for detecting pixel data representing stepped chrominance or luminance transitions characteristic of staircase aliasing in a source image and for producing an output image including selective antialiasing on the detected stepped transitions. The image processing logic operates as a post processor, but is able to give much better results than conventional convolution filtering.

Abstract: An appratus for inspecting lightness on the surface of an object having at least first and second surface portions different in lightness, wherein an image of the first and second surface portions of the object are taken under appropriate illumination, the taken image is memorized, first and second reference lightness of the first and second surface portions are defined respectively, whether or not each pixel of the taken image belongs to either one of pixel regions defining the first and second surface portions are determined in accordance with values defining preliminarily memorized pixel regions respectively, lightness difference between each pixel of the taken image corresponding to the first surface portion and the first reference lightness is calculated, lightness difference between each pixel of the taken image corresponding to the second surface portion and said second reference lightness are calculated, and quality in lightness on the surface of the object are determined on a basis of the respective

Abstract: In detecting patterns in data arranged in a spatial field of one, two or higher dimension, a pattern contrast signal is evaluated which measures the similarity to the pattern of the data around a location in the spatial field. The pattern is subsequently detected if the pattern contrast signal is sufficiently strong. There is, however, a risk of erroneous detection when a coincidental noise configuration causes an increased pattern contrast signal. The invention provides for a method and apparatus to discriminate against such erroneous detections. For this purpose, the method observes the extent to which a would-be pattern dominates the effect on the pattern contrast signal of the distribution of data values in the surroundings of the location, this distribution being taken to be typical of noise. In one embodiment, this is done by confirming that the pattern is sufficiently strong to suppress any other would-be pattern detections in the surroundings.

Abstract: An image processing apparatus comprises a first correction part for correcting an error of an input multilevel tone data so that a corrected data having a speficied number of bits is supplied, a multilevel rendition part for generating a multilevel rendition data and an error data from the corrected data being compared with a plurality of predetermined threshold levels, an error diffusion part for carrying out a prescribed error diffusion of the error data and for supplying a resulting error data for use in an error correction process of a subsequent data, and a second correction part for correcting the multilevel rendition data by a specified bit of the input multilevel tone data so that a corrected multilevel image data that is appropriate for being outputted by an output unit in which a multilevel tone data is assigned to each pixel included in an output image data is supplied.

Abstract: This invention is a method for forming halftone screen to prepare a multi-color separated halftone gradation image which is printable and reproducible by superposing an image signal obtained by scanning an original comprising continuous-tone color images with a halftone screen signal generated electrically, which comprises the steps of exposing and scanning a light spot of a predetermined size at a predetermined pitch to form halftone dots, and changing the number of said pitch so as to obtain an arbitrary screen line number.

Abstract: An image signal correcting circuit device includes an A/D conversion unit for converting an analog image signal output from an image reading unit into a digital signal, a storage unit for storing correction data, and a correction unit for performing correction on a signal based on the correction data stored in the storage unit. The correction data stored in the storage unit is difference data between at least two pixel signals in the digital signal which is generated by a correction data generating unit. Alternatively, the correction data stored in the storage unit is obtained by amplifying an analog reference signal by an amplification factor of m (m>1) and by converting the amplified analog signal into a digital correction signal by the A/D conversion unit.

Abstract: In an image processing system in which shading-compensation for eliminating shading-distortion contained inevitably in image light directed to an image sensor via optical systems is carried out, at least two latch unit for temporarily storing comparative values obtained by scanning white and black image planes are disposed between memory means for the comparative values and a processing unit for compensating image signals obtained as a result of optically scanning a given objective image. Since the comparative value of the pixel subsequent to a pixel in process is rendered on standby in one of the latch units in preparation for the image processing for the subsequent pixel, the processing time can be remarkably increased consequently to speed up the image processing.

Abstract: A method and an apparatus for processing an image signal generated in an image reading apparatus comprising a light source for illuminating a document, an optical system, and an optical detector for detecting a light which is reflected at a reading point on the document and passes through the optical system and for outputting an image signal corresponding to an amount of light detected thereby are disclosed. A secondary light source effect function which describes a degree that a light reflected at each point other than the reading point on the document affects the image signal corresponding to the reading point is obtained. The image signal output from the optical detector is corrected based on the secondary light source effect function and an image signal corresponding to each point so that a component corresponding to a light which is reflected at each point other than the reading point and affects the image signal corresponding to the reading point is eliminated from the image signal.

Abstract: An image recognizer which recognizes an image signal representing a mark on a mark sheet which has been written in a predetermined format judges whether or not the image signal may be considered to be constituted in accordance with the predetermined format, and recognize only the image signal which is judged to be constituted in accordance with the predetermined format.

Abstract: A reference original having a reference image is prepared and photoelectrically read with an image reader. The image thus obtained includes a true image and a false image which is called as a ghost or a flare. The relationship between the true image and the false image is detected. Then, an objective image to be reproduced is photoelectrically read with the image reader. The image thus obtained has a true image and a false image of an objective. The false image is eliminated using the relationship detected for the reference original.

Abstract: A digital halftone image is produced by providing a binary bit image pattern having a minimum visual noise for each density level in the image, and the binary bit patterns being correlated in a manner that reduces visual noise resulting from transitions between patterns. The patterns are addressed by pixel density and x,y location to produce a halftone image. The patterns are generated by employing a stochastic minimization technique with a constraint to insure correlation between patterns.

Abstract: The method and apparatus of the present invention performs the quantization, sampling, and final digital image signal reconstruction in a way that reduces quantization artifacts such as contouring while retaining desired spatial (temporal) frequency response and resolution. The technique of the present invention features a spatially varying quantization step, a low pass filtering step, a second spatially varying quantization step, and a comparison step to determine the reconstructed signal.

Abstract: The invention provides an image binarizing apparatus which includes multi-value image window circuitry for retrieving multi-value image data; a first binarizing circuit for binarizing the multi-value image data in accordance with a variable threshold determined based on the multi-value image data of pixels around a desired pixel; a second binarizing circuit for binarizing the multi-value image data in accordance with a predetermined threshold; and binary image window circuitry for retrieving image data which has been binarized by the second binarizing circuit.

Abstract: An image restoration apparatus comprises an image display device for displaying an image estimated as a nondegraded original image, a lens system for focusing the estimated image displayed on the image display device, an image input means for photographing an image focused by the lens system and for receiving the photographed image as image information, a comparing means for comparing the input image information received by the image input means with degraded image information prepared beforehand to obtain a difference therebetween, and a restoring means for performing restoration of an original image by changing the estimated image by using a random number on the basis of the difference calculated by the comparing means.

Abstract: A method of transformation of any random sample of a surface texture pattern into a replicatable unit for computer graphics applications that can join together without borders to cover any desired surface area. The present invention is particularly well suited for obtaining texture patterns from high resolution photographs of actual surfaces to be used in a "texture library" of realistic replicatable fill patterns. In the preferred embodiment, the invention provides a method for identifying and isolating discontinuities in a texture pattern. The invention facilitates the smoothing of the isolated border discontinuities to produce a transformed, borderless texture sample.

Abstract: An image data transmission system performs a coding of a plurality of picture elements in units of blocks. In order to prevent a deterioration of an image quality caused due to a loss of a packet cell on a transmission line without increasing a volume of data to be transmitted, a unit for producing a signal designating a loss compensation method to be performed on a receiving side is provided to be performed on a transmission side. The receiving side provides a unit for detecting a loss of the packet or cell and a unit for compensating the lost block data by the loss compensating method designated by the transmission side.

Abstract: A document processing system (DPS) having a closed feedback loop for improving the quality of the printed form of images that have been scanned into the DPS by scanners. The DPS includes a print path. The closed feedback loop automatically calibrates the print path such that printed documents have a true representation of the scanned image. The closed feedback loop operates as follows. First, a calibration image for the print path is created. Then, the calibration image is processed in the DPS. Then, distortions in the calibration image, caused by the processing, are measured. Then, calibration coefficients for offsetting the distortions are calculated. Finally, the image of the original document is precompensated by modifying the image according to the calibration coefficients.

Abstract: The invention is a high speed error diffusion process consisting of repetitive computational cycles in which a binary print value is determined from an error-diffused pixel in a continuous tone image. In each cycle, the computation of the previous pixel error exploits computations made during the previous cycle. Specifically, for a continuous tone image consisting of n-bit pixels, the n least significant bits of the previous pixel error are computed during the previous cycle and its sign bit is determined during the current cycle. The n least significant bits of the previous pixel error are the n least significant bits of the error-diffused pixel of the previous cycle. The sign bit of the previous pixel error is determined during the current cycle from the three most significant bits of the error-diffused pixel value of the previous cycle and from the binary print value of the previous cycle.

Abstract: An image quality control system for an image processing system for producing an image of high quality by removing noise and mesh-dot components from image input signals representing a scanned original image, the image quality control system comprises a low-pass smoothing filter adapted for removing from image input signals representing a halftone image substantially all of any mesh-dot component, for smoothing the image input signals representing the halftone image, and for producing smoothed output signals representing the smoothed image input signals, a smoothing modulation table for modulating the smoothed output signals of the smoothing filter to produce modulated smoothed output signals, a bandpass edge detect filter for detecting edge component signals of the image input signals, the edge component signals comprising a high frequency component of the image input signals, the edge detect filter producing edge output signals, an edge emphasis modulation table for modulating the edge output signals to prod

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: Image reading apparatus having a D/A converter with a controllable output includes a light source for illuminating an original image. A reading device is provided for photoelectrically reading the original image illuminated by the light source and generating an analog image signal. A D/A converter is provided having a digital input terminal, an analog output terminal, and a reference terminal. The analog image signal generated from the reading device is applied to the reference terminal. The D/A converter attenuates the level of the analog image signal applied to the reference terminal based on a damping factor corresponding to the digital data applied to the digital input terminal. The thus-attenuated analog image signal is then output to the analog output terminal. An amplifier is provided for amplifying the attenuated analog image signal output from the analog output terminal of the D/A converter.

Abstract: An image processor performs error diffusion by thresholding an incoming gray pixel to black or white, comparing the difference between the black or white print value and the incoming pixel gray level and superimposing the difference on the next pixel gray level. The threshold value is read out from a threshold matrix which has been modulated with a pattern which is complementary to the known artifact pattern of the error diffusion process. Typically, the threshold matrix has sparce threshold values along one of its diagonals, the direction of the diagonal being perpendicular to the prevailing direction of artifacts generated by the error diffusion algorithm.

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 digital signal is provided by correcting image signal distortions contained in an image signal outputted from an elongated direct contact type image sensor in an image reader such as a facsimile device, which image sensor reads patterns on a document in contact with the document. The image signal distortions of the sensor output are so-called shading distortions due to sensitivity distribution of sensor elements or distribution of light from light sources onto the document. Signal distortions are corrected from both a white signal outputted from the sensor when a white document is read and a black signal outputted when a black document is read. The white signal and the black signal are stored and reproduced to generate a reference signal which is obtained by dividing the voltage range across both the signals at a predetermined ratio. The digital signal is obtained by comparing the sensor output with the reference signal.

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 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 processing apparatus has a CCD sensor for reading an original image, comparators and latches for detecting maximum and minimum levels of the image signal from the CCD sensor, a coordinate detector for detecting coordinate positions on the original, and a CPU with a memory for determining a slice level and, quantizing the image signal in accordance with an algorithm stored in the memory.

Abstract: A facsimile machine includes a scanner, a plotter, a communicating device, a memory storing the image data supplied from the scanner and supplied, through the communicating device, from a source facsimile machine coupled to the transmission line through a network, a second memory storing a plurality of programs each defining a procedure for relaying the image data supplied from the communicating device to at least one destination facsimile machine, and an input device inputting the plurality of programs into the second memory.

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

Abstract: Method and systems for combatting degradation in the transmission or storage of data signals especially useful in the field of motion picture or television signal transmission, such that an advanced receiver can decode that information to provide improved picture quality, while a standard receiver will display an image with minimally visible impairments. A data signal can be decomposed into a low frequency signal and a high frequency signal, and that the high frequency signal can then be modified by the application of a series of scaling factors over selected regions in response to local variance of data values in such regions. The low frequency signal and the modified high frequency signal are then combined and transmitted (or recorded) as a modulated facsimile of the data signal, together with the scaling factors.

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: 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: A facsimile machine has an error correction mode in conformance with the CCITT recommendations. An image information read out from a first memory is recorded on a recording device when it is in a recordable state and is temporarily stored in a second memory when the recording device is in a non-recordable state and the second memory has an empty region. A reception process is discontinued when the recording device is in the non-recordable state or when no empty region is available in the second memory, and a message indicating that an image information is stored in the first memory is displayed when the reception process is discontinued. The image information read out from the first memory is recorded on the recording device when it resumes the recordable state after the reception process is discontinued.

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: A method for use in a recursive spatial filter which interchanges the value of a control pixel with that of the value of a predetermined one of the surrounding pixels in a pixel mask when a specific image pattern occurs in the digital image. The use of such a method eliminates certain highly visible grain patterns from the halftoned digital image while preserving the average gray level.

Abstract: A document scanner for utilization with a word processing and/or graphics processing equipment, such as a personal computer environment. The document scanner provides improved pixel compensation and gamma compensation techniques as well as improved control in the illumination process of the scanning of a document.

Abstract: A facsimile transmitting system is provided, wherein information recorded on a document or docments is read and transmitted. Prior to transmission, the amount of information recorded on the document is detected. A charge is calcualted prior to transmission based on the detected amount of recorded information. Money or the like corresponding to the calculated charge is received. Thereafter, information read from the documents is transmitted. The money can be received via a charge receiving unit which responds to a card storing recorded monetary value. The receiving unit reads the value from the card, substracts a value corresponding to the calculated charge from the read value, and records the result of this subtraction onto the card.

Abstract: An image signal processing apparatus for converting input signal values representing density levels of successive picture elements of an image to corresponding bi-level signal values, whereby a conversion error for an object picture element is apportioned among a set of unprocessed adjacent picture elements, to update respective values of accumulated error. Each input signal value is compensated, prior to conversion, by a value derived from the total accumulated errors of the object picture element and these adjacent picture elements, while the conversion error is derived by subtracting from the bi-level output value a value obtained by compensating the input signal by the accumulated error for the object picture element.

Abstract: A digital halftone image is produced by providing a binary bit image pattern having a minimum visual noise for each density level in an image. The patterns are produced by employing a stochastic combinatorial minimization technique and a human visual system modulation transfer function (MTF) weighting function to generate a halftone pattern for each density level of the multi-level digital image signal. A halftone image is produced by modularly addressing these patterns with each pixel value in the image.

Abstract: This invention relates to a method for converting a grayscale image to a bitonal image which provides improved tonal rendition with minimal loss of resolution. The invention attenuates the low spatial frequency component of the digital image and uses a similarly attenuated thresholder to convert the image to a bitonal image. When used with a dither type thresholder, this technique allows for simultaneous "continuous tone" and "line art" thresholding with minimal circuit complexity.

Abstract: Imagery data is compressed by subdividing the data into a plurality of blocks. Each block is encoded into a bit map and a pair of threshold values. The bit map provides an array of binary encoded imagery data-representative vector combinations. A vector combination is subdivided into a set of adjacent sub-blocks, each which is examined to determine whether or not it is associated with a prescribed attribute of the image. If the vector is associated with a prescribed attribute, a code representative of that attribute is generated. If the vector is not associated with a prescribed attribute of the image, prescribed portions of the vector are inverted to derive modified vectors that are associated with prescribed image attributes. For each such modified vector a corresponding code is generated. Using each of these corresponding codes, image data is effectively reconstructed and then compared with the original image data.

Abstract: An adaptive thresholding technique is calculated by using a real-time 16 pixel running average (RA) 18 to which is added on offset value. The offset value 38 is the product of a programmable factor (alpha) and a Sum Absolute Difference (SAD) noise measurement. The adaptive threshold 42 is compared by a comparator 48 with a delayed analog video signal intensity value on line 46 for the pixel associated with the adaptive threshold. The comparator 48 provides a binary video output for further processing. A relative video output may also be provided by taking the difference of the analog video signal 46 and its corresponding running average 18.