High Points Recognition Method of Scraped Surface Based on Background Subtraction
Using computer vision library OpenCV, a method of automatic recognition high points of scraped workpiece surface is presented. The image is dealt with by background subtraction, Median filtering, morphological processing, image negates, contour finding and drawing contours. In order to accurately and efficiently recognize the high-point contours and mark its center positions, mathematical morphology and specific processing function were used.
Background Extraction of Color Video Based on the Frame-Difference
Based on the frame-difference of color video stream during a time interval,we can extract the real-time background image of the video with moving objects in it.By using comprehensive means of red,green and blue components,this paper conducts a more in-depth algorithm to real-time extraction of image background problem of moving object detection.The research shows that,if the time interval is too short,the extracted background will have holes in it;if the time interval is too long,the extracted background will not be real time.This will cause errors to follow processing of moving objects detection.Both the realtime and the holes of the extracted background can has a good result if we select a reasonable time interval according to the size and the moving velocities of the objects in video.
Development of a novel laser-based measuring system for the thread profile of ballscrew
Abstract Based on the theory of laser measurement, a novel laser-based system to measure the thread profile of ballscrew has been proposed, which integrates the triangulation laser measuring system and the dual-axis rotary stage. The proposed system is made of the laser-based measuring unit to detect the longitudinal section of the thread profile and the dual-axis rotary stage for the movement of the undetected object. The experimental results show that the parameters of the measurements for the threaded gauge are in the tolerance range. Moreover, the measurement errors of this non-contact measuring technique are analyzed by the comparison between the proposed system and the coordinate measuring machine (CMM) system. The maximum error band of the measurements for the screw and the nut is about 4 and 4.5 μm, respectively.