Study On Computer-Aided Measurement System For Contour Of Head Based On Volume Visualization

As the classification of ordinary goggles in sales is not detailed, it is difficult to meet the wearing comfort requirements of different groups of people. During the design phase, it is necessary to acquire mass head characteristic data from different crowds guiding the ergonomic design of goggle product. Through the personalized design, the practical utility of goggle and user experience can be guaranteed. However, the precision of traditional approaches based on manual measurement is low, and it is hard to gather people and unify measuring standard. With the development of computer and volume visualization technologies in medical field, there has been a great innovation in the application of scanning images. Through computer-aided measuring methods, 3D model of volume data can be reconstructed rapidly. Besides, as characteristic parameters of human on the visual model can be measured easily with the help of graphic interaction principles, the problems in traditional manual measurement can be avoided. Due to the discussion above, it is known that it has important research significance and application value to do some researches, which on how to accurately extract contour data of human's head, how to obtain high quality 3D model through volume visualization technology, and how to design the computer-aided measurement system with great interactive performance to improve the accuracy and efficiency of measurement.Some implemented issues about the measurement for contour of 3D head model, including image processing technology, volume visualization technology and computer-aided measuring methods for medical image, are analyzed and researched in this paper intensively. On this purpose, some improvements for current used methods and innovative algorithms are proposed, and a computer-aided measurement system is developed for contour of head by using those proposed techniques. The main research contents of the paper are listed below:1. In order to extract the contour of head medical image effectively, on the base of image characteristics of CT and MRI technologies, an extracting method for contour of head is proposed by combining multiple segmentation algorithms. This method achieves keeping intactness of the contour and ensuring quickness and accuracy of the extraction process, which is quite important for the measurement.2. In order to achieve high quality reconstruction of human's head, some implemented issues about surface rendering algorithm and volume rendering algorithm are analyzed, especially the theory and implementation of MC algorithm. For improving the ambiguity during reconstruction and smooth effect, their improved methods are discussed so that smoothness of the realistic model can well meet the need of real-time rendering.3. In order to improve the operating performance of the model interaction, and accurately measure the characteristic parameters of contours from the head model, an efficient measuring method for contours of head is developed. In this method, principles of position transform and 3D graphics picking mechanism are employed for locating characteristic point on the model, moreover, contour image on the model is obtained on the basis of simulating cut and geometrical transformation, and 2D contour coordinate data is acquired by contour tracking method. Finally contour parameters of the model are measured and exported according to application requirements.The system of computer-aided measurement for contour of head is finally established based on the above researches. The design solution, overall framework, function modules and key technologies are discussed in detail; Experimental results show that: the system can effectively achieve measuring contour parameters of 3D head model, and the actual head morphological characteristics are reflected accurately and intuitively, which can be used to guide the data acquiring process for goggle personalized design.