Abstract: An image processing method and device computes the image quality as an evaluation value, determine the image quality based on this evaluation value, and employ a restoration process in accordance with image quality when this image quality is poor.

Abstract: In an image processing apparatus in which digital data of a certain number (m) of levels are converted into digital data of a larger number (n) of levels, then subjected to certain desired editing processing, and again digitized to data of the original number (m) of levels. The redigitization to m levels is conducted by determining the average density of a predetermined area, utilizing data of pixels already redigitized to m levels, and redigitizing the data of n levels into m levels, utilizing the average value. This process significantly reduces the amount of data processing required without formation of an unpleasant texture on the image resulting from errors in digitization.

Abstract: An image rendering system, for generating discrete tone image data representing a continuous-tone image for rendering by a rendering device, the image rendering system includes a stochastic threshold array generating arrangement and an image data processing section. The stochastic threshold array generating arrangement generates a plurality of stochastic threshold arrays from a random seed pattern that have been subsequently optimized to reduce image artifacts in the rendering of tones. Each pattern is optimized to reflect (i) a selected trade-off between grain and possible mottle in the rendered image, (ii) distortions introduced by the rendering device in rendering an image defined by the pattern and an observer in viewing the image, and (iii) boundary effects so that the patterns, when tiled together, have optimal visual characteristics proximate their respective edges.

Abstract: An image read-out and processing apparatus comprises an image read-out section, which carries out a preliminary readout and a final readout, and an image processing section. In the final readout, the amount of light irradiated to an image storage sheet, on which an image has been recorded, and/or the light accumulation time of a photoelectric conversion device is adjusted appropriately in accordance with preliminary read-out image information obtained from the preliminary readout. The image processing section is provided with a color and density correcting device for correcting the final read-out image information such that the color and the density of the image may become appropriate, and for determining the degree of correction, which is carried out on the final read-out image information, in accordance with a parameter, which is set in accordance with the preliminary read-out image information. A parameter correcting device corrects the parameter in accordance with the final read-out image information.

Abstract: A method and system of analyzing sequences of road images taken by a camera carried on board of a vehicle. A luminance signal of the road images from which contours of the road are extracted is generated. An analysis of color video signals based on the fact that the colorimetric components of a road region in an image do not include a green or red dominant is then combined with the luminance signal processing, in order to confirm, with good reliability, the limits of the road in the image on the basis of the contours. A mask of the road is then established. This method and system are applicable, in particular, to detecting obstacles on the road, and the information which it generates may be combined with information originating from other detectors in an obstacle detection system applicable to motor vehicle traffic.

Abstract: The present invention determines the epicardial boundary, being a closed curve dividing the myocardium from the tissue and blood surrounding the left ventricle. A mean and standard deviation is determined for pixels of a medical image of the subject's myocardial tissue. These are used to define a "goodness function" over the image which is positive for pixels statistically likely to be myocardial tissue, and negative for other pixels. An initial curve for modeling the epicardium in radial coordinates starts with a curve of inner myocardial boundary obtained my conventional imaging techniques. This curve is then iteratively updated to maximize the total "goodness function" of the region encompassed.

Abstract: In a method of measuring noise in image signals, a number of noise estimates (SAD) is calculated (1). Subsequently, it is determined (3-9) which noise estimation interval [A, B] out of a plurality of predetermined noise estimation intervals [A, B] contains at least a predetermined number of noise estimates (SAD) and has at the same time the lowest upper interval boundary. The output noise measurement value depends on the determined noise estimation interval.

Abstract: A method is described for the rendering of an image on a carrier by a rendering system having a restricted density resolution. A classic screening method for a binary rendering technique is extrapolated to a plurality of energy levels that belong to three classes: non-marking, non-stable and marking stable energy levels. For each class, specific rules must be respected, in order to obtain predictable results without density discontinuities on the carrier. The methods make full use of the spatial and density resolution of the rendering system in areas of high density and increase the reproducibility of low densities by giving up some spatial resolution in the lower density regions.

Abstract: An improved error diffusion method for incorporating into a halftoning algorithm for processing gray scale images to counterpart binary images. The improved error diffusion method adopts a tone scale function to process the input gray scale image before proceeding with the halftoning (error diffusion) processing in order to improve the image darkening problem caused by the conventional error diffusion method and a noise correction process to eliminate the background noises resulted from the accumulated error of the conventional error diffusion method. The proceeding of the tone scaling process and the halftoning process are parallel with the correction process so that errors generated in either one will not affect the other.

Abstract: An image binarizing apparatus, which comprises an image sensor for inputting a character image or a line image, an A/D converter for digitizing the output of the image sensor, a frame memory for temporary storage of the digital image, a window circuit for generating address information for dividing the stored image into a predetermined number of partial images, a brightness extractor for obtaining the highest brightness, lowest brightness and average brightness for the pixels for each block, a neural network which provides the optimum threshold value based on pre-learned data when receiving the highest brightness, lowest brightness and average brightness, a binarizer for binarizing each pixel of a partial image block from the frame memory based on the optimum threshold value ("white pixel" when the value of the brightness of the pixel is larger than the output value of the neural network, and "black pixel" when the value of the brightness of the pixel is smaller than the output value of the neural network), a

Abstract: There is disclosed a method for converting multi-level image data into binary image data and an apparatus therefor. An average density is calculated from the already binarized density of pixels positioned in a predetermined area around an object pixel, and the threshold value for binarization is set by adding a fixed bias value and varying dither signals to the average density, and the error generated in the binarization is distributed to the unbinarized pixels positioned behind. The addition of the fixed bias prevents formation of a spot-free white area in the vicinity of an edge or in the initial stage of processing, and the addition of dither signals prevents texture formation in the low density area.

Abstract: An image testing device captures an image of a test object using a TV camera and raster-scans the image to search the test object for a scratch or spot. The device protects its test precision from being deteriorated by lowered brightness of an illuminator and properly maintains the illuminator by outputting an alarm on detecting a lowering of the illuminator. To realize the capabilities of the image testing device, it comprises a brightness measure circuit, a general determination circuit, etc. The brightness measure circuit receives a multivalued gray image signal or image data from the frame memory through a switching unit, obtains an average value of picture elements in a brightness measure area in a test object image, and outputs it as a measured brightness signal. The general determination circuit corrects, in proportion to a measured brightness a binarization threshold for use in detecting a picture element indicating a defect.

Abstract: In a figure recognition apparatus, a direction of a vector starting from a sample point most recently stored in a position data memory and terminating at an attention point is compared to an average value of directions of sample point vectors stored in the position data memory. The result of the comparison is used for deciding whether to discard the attention point.

Abstract: A rear surface emission type light emitting diode emits light beams produced at a narrow emanating region out of the rear surface of the substrate. Preferably a device chip should be directly equipped with a lens on the rear surface. A plurality of light emitting devices with a package are laid on an XY-stage which can move in an XY-plane. A camera, a dispenser and a vacuum collet can transfer in Z-direction. The distances and the directions among the camera, the dispenser and the collet are predetermined values. The chip is actually examined by letting it emit light beams from the emanating region. The light is observed by the camera to obtain light power distribution on individual pixels. From the light power, the center of the emanating region is determined. The XY-stage is displaced till the center of the emanating region coincides with the center of the camera. Then the XY-stage is moved by the predetermined distance to send the chip just beneath the dispenser.

Abstract: There is disclosed an image processing apparatus for intermediate tone processing of an image signal into a binary signal, capable of providing a reproduced image with excellent resolution and gradation with a simple structure, and without the periodic texture inherent to the conventional error dispersing method or average density conserving method. The disclosed apparatus determines the average density of an already binarized predetermined image area, binary digitizing the image signal of a contemplated pixel, utilizing the determined average density as the threshold value, and distributing the error, generated in the binary digitization, to the image data of plural pixels to be digitized thereafter with certain distribution factors. The distribution factors are randomly changed according to random numbers generated by a generator, so that the reproduced image is free from periodic patterns resulting from periodic distributions of the errors.

Abstract: A method of inspecting the surfaces of materials to be examined, wherein the surface is scanned line by line by an optical measurement pickup and the signal furnished by the measurement pickup is processed in order to obtain information about the consistency of the surface of the material to be examined, with the picked up lines each being processed in sections in that for each section the average, the maximum and/or the minimum values, as well as an intermediate value, which is representative of the respective section and which is used for further processing, are determined. If the maximum or minimum values lie outside of a given tolerance zone that extends around the average value, the intermediate value equals the maximum or minimum, respectively, otherwise it equals the average value.

Abstract: An image processing apparatus is configured such that an image is photoelectrically read, a reference signal, which follows an output signal from a reading circuit, is formed, whether the level of the output signal is greater or smaller than the level of the reference signal is detected, and a capacitor, for performing a charging operation or a discharging operation in accordance with a result of the detection, is charged during a predetermined time period before the start of the output of the output signal from the reading circuit.

Abstract: A post-processing filter apparatus for use in an image signal decoding system, capable of improving the image quality of the system, comprises a memory for storing decoded image data of a current frame; a filter for filtering target pixel data in the stored decoded image data to thereby produce filtered target pixel data, wherein the target pixel data represents the value of a pixel to be filtered; a calculator for calculating an absolute difference value between an original target pixel data and the filtered target pixel data; a first circuit for selectively generating a first or a second threshold value based on the decoded image data and the target pixel data; a second circuit for updating the stored target pixel data with the filtered target pixel data if the absolute difference value is smaller than the generated threshold value; and a third circuit for sequentially updating the stored target pixel value with corrected target pixel data T times if the absolute difference value is equal to or larger than

Abstract: A gradient conversion table is supplied with N-bit input image data and outputs M-bit image data, and a random-number generator outputs K-bit random-number data (M.gtoreq.K). An adder adds the K-bit random-number data to low-order K bits of the M-bit image data outputted from the gradient conversion table, and outputs high-order L bits {L>(M-K)} of the sum as output image data. Low-order bits of the output image data are dispersed to produce an image with any banding of low visibility.

Abstract: In a mail sorting system 10, output pixel intensities of an optical scanner 18 have their contrast locally enhanced. A contrast enhancer 24 uses statistical methods (averaging, standard deviation) coupled with empirical stretch and offset data stored in a ROM 25, to enhance pixel contrast in a pipelined processing operation.

Abstract: In a thresholding method for segmenting gray scale image which is less dependent on the concentration distribution of the input image, the threshold in determined as a zero-cross point of a histogram difference between the concentration histograms for the gray scale image within the window at a window position at which the window contains more high concentration region and at a window position at which the window contains more low concentration region. Also, in a method of determining a background concentration distribution from an image having an arbitrarily distributed pattern, the background concentration level is determined as a peak concentration or a mean value concentration of a low concentration section of the histogram difference of the concentration histograms for two associated windows. Also.

Abstract: An adaptive spatial filter for digital image processing selectively performs spatial high pass filtering of an input digital signal to produce an output pixel value having an enhanced signal level using a gain factor that effects a variable degree of enhancement of the input pixel, so that pixels whose activity values are close to an iteratively adjustable activity threshold level will be emphasized significantly less than pixels whose associated activity values are substantially above the threshold level. The activity threshold level is selectively updated at the end of a scan line in accordance with prescribed spatial activity criteria, so as to effectively prevent discontinuities in the threshold level during line-by-line adjustment and to take into account how `noisy` the background is.

Abstract: In a machine vision system, a pixel-discrimination threshold level, for determining whether pixels are to be assigned one or the other of two values, is established according to parameters obtained in an initialization procedure. During initialization, a test set of items is assembled and data is entered representing indicia appearing on each item of the test set. It is then determined, for each of a range of possible threshold levels, whether the machine vision system correctly recognizes the indicia on the respective test items. Based on the thresholds which permitted correct recognition, threshold parameters are calculated for each test item and average parameters are calculated from the test item parameters. The average parameters are used to set pixel-discrimination thresholds for subsequent recognition operations.