A Study On The Application Of Non-contact Foot Parameter Measurement

The new technology, which combined with optic measurement technology and computer vision theory to solve reverse engineering, is a rising technology from1990. With the promotion of application, this technique has been applied in the research of foot3-d outline reconstruction. However, along with development of the foot biomechanics research, the complex foot physiology phenomenon is systematic, digital for the objective description and analyzed by scientists, and then the modern diversified health view in sport and life is explored. So the important point of the foot engineering application research is not only focusing on foot shape characteristics of measurement, but also combining with foot biomechanical study closely. By measuring the foot digital physiological characteristic parameters and Combing with theoretical of foot biomechanics research, the design of shoes for sports, health and scientific can be guided. At the same time, to collect the sample data of the physiological characteristic parameter can further promote the foot of biomechanics research.The thesis studies the measurement problem of foot characteristic parameters for physiological analysis and aided design of shoe and design and realizes a system which could measure automatically foot physiological characteristics parameters. Based on optical measurement and computer vision theory, and starting from the feature what researched by the biomechanics of the foot, the system could automatically measure the foot physiological parameters which including traditional foot shape parameters, the area of plantar pressure and foot3-d outline. By the use of hardware system which had been completed actually to measure human foot automatically, and compared the measurement results with traditional manual measurements results, while the experimental results show that the system has higher accuracy and practicality. The main findings of this study are as follows:1.Combining with foot biomechanical study, the thesis introduces the characteristic of a more scientific and effective foot parameter measurement system, and gives the system space layout diagram. The measurement of foot divided into plantar scan and foot contour reconstruction in system. By processing the image of foot scan, calculating automatically traditional foot characteristic parameters such as foot long, foot wide and then the system focus on calculating the plantar pressure distribution area; at the same time, by reconstructing foot surface contour, the system calculates the foot circumference characteristic parameters to assist shoe last design. Compared with the traditional foot shape reconstruction, the system could measure more foot information, and meet needs of the modern people sports and health.2.In foot scan image processing, in this paper, the method of OTSU threshold was used to segment contour area of foot, then mapping plantar contour coordinates to world coordinates, and finally, calculating automatically traditional foot characteristic parameters such as foot long, foot wide that according to the definition of foot parameter measurement. In Plantar pressure area segment, pressure level is divided into three levers and the method of OTSU threshold was used to calculate threshold for segmentation which corresponds to the pressure level, and then complete segmentation of the plantar pressure region. The experimental results show that this method can calculate the part of the foot characteristic parameters fast, effective while complete plantar pressure region segmentation.3.This thesis first use OTSU to preliminary segment the line structure light band, Because the processing of the large number of line structured light image spends a lot of time in reconstruction of foot surface contour, and then use the gray center method is to solve the linear structured light center, while eliminate the center pixel of the non-structured light after the pruning process. The experimental results show that, the proposed method improves the accuracy of the outline of the foot surface reconstruction, and speed up the image processing time.4.The thesis set up the experimental platform, and completes the measurement of the real human foot. Finally, error analysis was made by comparing experimental results with the results which use traditional manual methods to measure. The experimental results show that system has a good application and extension.