Abstract: A shape detection apparatus able to accurately detect the image position of a target object even when the shape of the scanning window does not match the shape of the image of the target, and even when the scanning position of the scanning window does not precisely match the image position of the target is provided. This shape detection apparatus comprises a video image producer; an image memory; an approximate position evaluator for evaluating the approximate position of the image of the target; an edge point detector for defining plural sampling line windows having a predetermined length for detecting the image density at the detected approximate position of the image, and detecting image density edge points in these sampling line windows as the contour point positions of the target image; and a detection window setter for setting the contour lines of the target image from the detected contour point positions.

Abstract: A position detection apparatus for detecting a position of an object includes a video image producer which produces a video image signal representing the object image. The video image signal is divided into first and second level portions by an edge point. An edge point detector detects the edge point where said level difference is greater than a threshold level. A window filter is provided to increase this level difference to a level greater than a threshold so that the edge point detector can detect the edge point even when the level difference is smaller than the threshold level. A shape detector detects the position of the object based on thus detected edge point.

Abstract: A method of position recognition, includes a step of obtaining a gray image by picking up an image of an object by an image pickup device; a step of scanning the gray image by a profile scanning window composed of a plurality of gray-level detection areas which cross a scanning profile corresponding to a profile of the object on the gray image and using to measure a gray-level representative value of an inner-side gray-level detection area and a gray-level representative value of an outer-side gray-level detection area which are inside and outside of the scanning profile; a step of calculating for each gray-level detection area an absolute value of a difference between the measured gray-level representative value of an inner-side gray-level detection area and the measured gray-level representative value of an outer-side gray-level detection area, and a step of detecting a position of the profile scanning window where a number of such gray-level detection areas in which the absolute value is greater than a spe

Abstract: An alignment detection apparatus is able to accurately detect the alignment condition of an upper hole and a lower hole located under the upper hole even when a scanning window does not precisely match either of the two holes. This alignment detection apparatus comprises an image producer which produces a digital density image indicative of these two holes. A position detector detects positions of the holes based on the digital image signal and produces a position signal. A displacement detector detects a distance between the upper hole and lower hole based on the position signal and produces a displacement signal indicative of the thus detected distance. Based on the displacement signal, the alignment condition of two holes including the information of how the lower hole edge is displaced from the upper hole edge can be detected.

Abstract: Each pixel of a density reference area of a reference image is assigned a predetermined coefficient value in accordance with whether the pixel is located within a peripheral boundary of a to be detected shape, external the peripheral boundary of the to-be-detected shape, or on the peripheral boundary of the to-be-detected shape. An actual image of an object containing the to-be-detected shape is then obtained, and after setting a target pixel of the resultant image, the image density of each pixel is multiplied by the coefficient values of the density reference area of the reference image. The resultant products are transformed into a density correlation value for the target pixel. The location of the target pixel is then scanned to determine the location of a target pixel at which a maximum or a minimum density correlation value is obtained. The thus determined location is detected as the location of the to-be-detected shape within the object.

Abstract: A method for position recognition, includes the steps of: picking up an image of an object having a circular arc shape as at least part of its profile, by an image pickup device; converting image information of the picked-up image in gray image data and storing the gray image data into a storage device; scanning the stored gray image with a profile scanning window composed of plural gray-level detection areas crossing an imaginary scanning circular profile corresponding to the shape on the gray image and arranged in circular along the scanning circular profile and using it to measure gray-level representative values of an inner- and outer-side gray-level detection areas inside and outside of the scanning circular profile; calculating, at each scanning position during scanning and for each detection area, an absolute value of a difference between the measured gray-level representative values of the inner- and outer-side gray-level detection areas; determining a number of such detection areas in which the absol

Abstract: Positions of overlapping first and second circular holes of respective first and second objects are detected, the first and second objects to be screwed together by a robotic screwing mechanism. An upper surface of the first object is viewed with an image pick-up device to obtain an image of the first circular hole and a partial image of the second circular hole which overlaps the image of the first circular hole. Two maximally spaced-apart boundary points from among the boundary points along an outer periphery of the partial image are detected. First and second circles within an image frame are defined which include the two maximally spaced-apart boundary points and which have respective centers of gravity which are symmetric to each other relative to a line segment connecting the maximally spaced-apart boundary points. The positions of the first and second circular holes are detected based on the defined first and second circles within the image frame.