Abstract: A number plate recognition system has structure for inputting an image; structure for calculating outlines of each configuration included in an input image, as well as for recognizing a configuration with the maximal outline size as the plate area. The areas in an image except the above plate area are masked, and the numbers are determined by using Euler numbers after calculating Euler numbers for each configuration within the above plate area.

Abstract: An image processing system has an input portion to which pixel data is inputted, a convolution processing portion processing each set of pixels in a predetermined convolution area so as to output a processed data for every predetermined convolution area. A computational portion calculates a parameter necessary for a image processing according to the processed data from the convolution processing portion. A converting portion includes a selecting means, to which the output of the computational portion is inputted, a high speed memory to which the output of the selecting means is inputted and a light computational portion for performing light computation to which the output of the high speed memory is inputted and the output of which is inputted to the selecting means.

Abstract: An image processing system has an input portion to which pixel data is input. A convolution processing portion processes each set of pixels in a predetermined convolution area and outputs a processed data by every predetermined convolution area. A computational portion calculates a parameter necessary for a image processing according to the processed data from the convolution processing portion. A converting portion comprises a selector receiving the output of the computational portion, a high speed memory receiving the output of the selector and a light computational portion for performing a light computation to which the output of the high speed memory is input and the output of which is input to one input of the selector.

Abstract: A method for comparing two images including ridges with each other, comprising steps from i) to iv).i) Calculating density value of each pixel of an image to be examined and reference image; ii) detecting a direction with minimal change between each pixel and adjacent one, concerning to each pixel; iii) dividing the image to be examined and reference image, calculating an index according to the direction with minimal change as to each block; iv) using the index, it is judged if the image to be examined and reference image substantially coincide to each other.

Abstract: A system for determining a velocity of fluid flowing around an object generates a signal for an image of a fluid-flow surrounding the object. Based on the signal, the system determines a centroid for each particle in the fluid-flow, and calculates distances between centroids of two nearest particles. The system then determines a velocity distribution of the fluid-flow based on the distances.

Abstract: A 3-dimensional configuration recognition system comprising: a means for projecting a checker pattern onto a surface of a solid object; a means for thinning said checker pattern and for generating a thinned checker pattern; a means for extracting cross points of said thinned checker pattern; a couple of means for detecting 2-dimensional coordinate of said cross points; and a means for calculating 3-dimensional coordinate of said cross points from said 2-dimensional coordinate and positions of said couple of means.

Abstract: A method for storing information defining a configuration in an image scans an image, and distinguishes a background density level from a density level of the configuration. For scan lines, start pixels are identified as the first of a contiguous group of pixels having the configuration density encountered in the direction of a scan, and end pixels are identified as the last of a contiguous group of pixels having the configuration density. Chain codes are generated linking start and end pixels among differing scan lines, and start and end pixels are also indexed. Chain codes and indexes are stored as image representations.

Abstract: A method for processing images is useful for generating a chain code representation of a configuration of pixels in an image. The method stores a pixel representation in first frame memory. For each pixel, "convolution information" is stored in a second frame memory. Convolution information indicates whether neighborhood pixels are part of the configuration. In one embodiment, convolution information for an object pixel is a bit string. The location of a bit in the string corresponds to a direction of displacement from the object pixel. The value of a bit in the string indicates whether a neighborhood pixel located in the corresponding direction is part of the configuration. A first method for generating a chain code expression examines the convolution information for a bit which identifies an adjacent configuration pixel. Examination begins from a bit location determined from a prior code in the chain. The position of the identified bit is then the next code in the chain.

Abstract: An inspection method of liquid crystal panel by comparing characteristics of histogram of a part mounted on the panel with a reference histogram which is obtained from a part of the panel to be inspected.

Abstract: A method of generating a binarized image from an original image. Error values of binarized pixels in the neighborhood of a pixel to be processed are used to modify the pixel to be processed. The error values are filtered according to weighting factors which vary as a function of the density value of the pixel to be processed independent from the density values of the pixels in the neighborhood. The weighted error values are used to modify the pixel to be processed prior to comparing the pixel to be processed to a threshold.

Abstract: A fingerprint photographing system comprising: a prism having a detection surface where a finger is pressed thereon; a luminous source for irradiating light to the detection surface; a camera for detecting the light reflected upon the detection surface; and means for comparing the image before and after the finger is pressed upon the detection surface and for storing the image of fingerprint to a memory when the number of pixels of the image with a predetermined density difference is in the range of predetermined number.

Abstract: A method and apparatus for aligning first and second images uses closed contours of pixels from the images. In the preferred embodiment, a series of pixels is selected from along a contour in each image. The contours can be circles. The two pixel series are compared to determine a degree of concurrence. One series is shifted by one pixel relative to the other, and concurrence is determined after the shift. The series are shifted repeatedly until all shifts have been measured. The shift distance which results in the maximum concurrence is selected as a measure of the amount of rotation needed to align the images. After rotational alignment, one image is displaced by one relative to the other and the displaced images are compared to determine a degree of coincidence. The images are displaced eight times, each displacement testing one position in a different direction. When a displacement is found to give a higher degree of coincidence between the images, the images are displaced in that direction.

Abstract: An image processing method for finding concavity of a configuration comprising steps; arranging boundary pixels of the configuration according to chain order with indicating top points on convex hull of the configuration; and determining that a concavity is defined by the boundary pixels when a boundary pixel of a chain code is found, which chain code indicates a concavity.

Abstract: An image verification system for verifying whether a sample image corresponds to a reference image registered beforehand. A relationship between the sample and the reference image is stored when the sample image corresponds to the reference image. The sample image is compared with the reference image by verifying the sample and the reference according to the relationship between characteristics values of the sample and reference.

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 and apparatus for determining which pair of a plurality of objects in an image has a minimum separation distance. In the method, centroids of groups are ordered in a sequence according to X and Y coordinates. A distance is measured between a reference object and an object adjacent in the ordered sequence to the reference. Objects in the sequence which are not adjacent in the sequence to the reference are excluded from measurement based upon relationships between the coordinate values of the reference object, the adjacent object and the non adjacent object being evaluated for exclusion. This exclusion reduces the total number of steps necessary to determine which pair of objects has the minimum distance. Distance measurements are made to non-excluded objects. Similar steps are repeated for other reference objects. The pair objects which have the smallest measured distance are indicated as the objects having the minimum separation.

Abstract: A recognitiion method and system for associating a pattern, such as a printed character with an acoustic signal, such as speech. A multilevel power sequence is generated from the acoustic signal, and the sequence is segmented into phonemes. The multilevel power sequence is converted into a binary level sequence to reduce noise. The binary power sequence is accumulated to give a series whose elements are partial sums of the sequence as a function of time. The accumulated sequence is differentiated to give a series whose elements are the derivatives of the accumulated sequence as a function of time. The differentiated sequence is then associated with a pattern, such as a printed character.

Abstract: An image processing method generates a density concurrent matrix. An original image is shifted for generating a shifted image, with pixels in the shifted image corresponding to (conceptually overlapping) pixels in the original image. Bit strings are formed by combining a pixel density value of a pixel from the original image with a density value of a corresponding pixel from the shifted image. In an example, two 4-bit density values are combined into a single 8-bit string. Bit strings formed from pixel pairs are counted to give the number of occurrences of density pairs in the original and shifted image.

Abstract: An image processing method for generating a convex hull of a configuration in a digital image. Top points of the convex hull are selected. A reference line connecting the top points is defined. For each area between two adjacent top points, continuous pixels are selected from one top point toward the other so that each pixel is the nearest to the referfence line as well as between the reference line and a contour of the configuration. Distances from pixels to the reference line are calculated from chain codes.

Abstract: An image processing method for flatten=ing histogram with distribution comprising steps of:a density conversion table is generated for indicating to which densities each density is to be converted, as well as how many pixels are to be converted;the latter of the density is registered in an address designated by the former of the density in a converting circuit, and the number of pixels to be converted is registered in a count-down circuit;density of each pixel of an image is inputted to the converting circuit and the count-down circuit so that latter of the density is outputted from the converting circuit and that the number in an address designated by the density of each pixel is decreased by "1" on each input of the density;the density of each pixel is converted to the former density until the number is decreased to "0"; andpixels in the image of the density which corresponds to the number decreased to "0" is converted to an index density thereafter.