DIGITAL IMAGE MEASUREMENT DEVICE AND METHOD FOR MEASURING SPECIMEN SURFACE DEFORMATION BASED ON SUB-PIXEL CORNER RECOGNITION

摘要

A digital image measurement device for measuring a specimen surface deformation based on sub-pixel corner recognition, the device comprising: an image-measurement pressure chamber, a CMOS industrial camera, a camera support (15), a flexible lens hood (14), and a computer and matching measurement software. Further provided is a digital image measurement method for measuring a specimen surface deformation based on sub-pixel corner recognition. The method comprises discretizing a specimen (4) into several four-node finite elements by means of squares printed on the specimen (4), wherein the corners of a grid act as the nodes of each finite element; tracking deformation of a feature point in real time based on sub-pixel edge detection and corner recognition; capturing full-surface deformation information of the specimen (4) by means of a plane mirror (3) with an angle of 120 degrees between the two faces thereof behind the specimen (4); and performing splicing and error correction on three images to achieve full-surface deformation observation. The apparatus is simple, low in cost and high in precision, and can measure and track the deformation of feature points in real time to obtain the deformation field and the strain field of the entire surface.