A Study On Foot Reconstruction Measurement Based On Line-structured Light Scanning

With the development of the computer vision technology, reverse engineering based on computer vision has become a hot issue of scientific research today. As the reconstruction of free-form surface has high fidelity, it is widely used in manufacturing field. The introduction of the technology to the human foot three-dimensional reconstruction measurement research can greatly improve the efficiency and accuracy of the foot parameter measurement and promote foot physiological and structural analysis.This paper analyzes the current market demand status of foot type automatic reconstruction measurement system. A new method based on the linear structured light scan is developed. The system hardware is mainly composed of laser scanner platform, line-structured laser light, CMOS camera and a few other parts. The laser scanner platform is used to collect the image of the bottom of foot and calculate the related parameters of foot through image processing technology. Line structure light photos of instep are taken by2high resolution CMOS cameras from different angles. The3D instep surface contour is reconstructed and the parameters are calculated by the technology of computer vision and computer graphics.Compared with the domestic similar products, the system of this paper not only has the similar measuring precision but also has the lower cost and complexity. So it is suitable for further promotion in gait analysis, foot automatic measurement and personalized shoes design. The main findings of this paper are as follows:1. Through the demand analysis of the foot type automatic reconstruction measurement system, this paper put forward a new kind of scheme with simple construction and low cost. This paper introduces the working principle and the hardware structure design of the scheme.2. Through experiment contrast, this paper introduces the key technology and algorithm in the process of instep construction. Mainly divided into the following several aspects:(1) Instep line-structured light image processing. OTSU algorithm is used to extract the light band area and Zhang fast parallel thinning algorithm is used to thin the light band.(2) The repair of blind data in human heel zone by curve fitting. This paper analyzes the causes of blind data in human heel zone and compares the repair quality in common interpolation and approximation algorithm. At last we choose the least squares curve fitting algorithm to repair the blind data in human heel zone.(3) Instep3D surface reconstruction. The3D Delaunay triangulation algorithm is used to restructure the curved face of instep. Use VTK visualization class library to realize the instep surface3D reconstruction.3. This paper designs a contrast experiment between automatic measurement and manual measurement. The cause of system error is also analyzed. The experimental results show that this foot type automatic reconstruction measurement system has high reliability and accuracy. It can meet the needs of practical application in foot measurement.