Research On Measurement Method Of Eyeball Prominence Based On

Eye protrusion is one of the most common signs of orbital disease, and it is also an important medical problem. The traditional eye protrusion measurement methods include Hertel eye protrusion and CT scanning, which has some high cost and inconvenient problems. The measurement method based on computer vision is a non-contact, low cost method, and it has been widely used in many fields successfully. Therefore, this paper develops a non-contact measurement system based on binocular stereo vision. And we discuss the key technologies related to binocular stereo vision.The main work of this paper is as follows:1. We design an eye exophthalmos measurement hardware platform based on binocular stereo vision. The platform includes two cameras which has macro lens, six near-infrared lamp light and image acquisition equipment. The system is low cost. And the collected image of the eye region so clear that the pupil, iris and eyelid are clearly visible. And the image is smooth and without noise. The collected images can provide high quality data for the design of iris recognition, eye region location and eyelid detection. Based on the platform, the camera calibration algorithm is realized.2. We implement the key algorithm of the eye protrusion measurement system based on binocular stereo vision. Firstly, the feature extraction algorithm is proposed, which can overcome the limitation of the feature points in the eye area and overcome the characteristic is not obvious problem. This method uses the algorithm of pupil localization and SURF feature extraction based on Hough transform, then uses the RANSAC algorithm to realize the stereo matching. The matching accuracy is higher after the pole line matching, which provides an effective matching points. Next, we extracted the depth information of the key points according to the matching point pair. And we calculated the eye prominence compared with the manual measurement result. Finally, we analyzed the result and give the reason of the error.3. We develop a software which has a set of visual interface, all parameters and the image to be measured can be added manually. The system is convenient to use, and the results of three-dimensional can be viewed clearly.