Research On Auto-Portrait Robot Technology

Auto-portrait robot is a mechanical system which could draw face portrait automatically. Based on Ycbcr color space and iterative threshold method, we propose a face detection algorithm for extracting contour lines from color face images. By converting pixels of contour lines into vectorized points, the robot controller receives vectorization information and completes portrait drawing.Experimental results demonstrate successful contour extracting and portrait drawing over a wide range of facial variations.Face detection is the most crucial technology in an auto-portrait robot, and it plays an important role in applications such as video surveillance, human computer interface, face recognition, and face image database management. Although many different algorithms exist to perform face detection, each has its own weaknesses and strengths. These algorithms are computationally expensive. So in this paper we proposed a fast algorithm to increase the speed of face detection. The primary research contents and results are as follows:We researched on hardware of image acquisition system and algorithms of shooting human face images.We reviewed skin color method and iterative threshold method, and compare different color models with each other. We extracted external-contour of human body and clothes with an algorithm basing on Ycbcr color space and iterative threshold method.To detect eyes and eyebrows, we propose a shadow casting technique algorithm based on searching, it has a good effect to the whole image of human face boundary.We research on vectorization method based on 8 points neighborhood without interference in order to make robot controller understand contour information.In section 5 we propose the whole process that robot arm follows for drawing contour lines. We solved the most crucial problem of communication between coordinate outside and controller variables inside. In Visual C++ 6.0, we realized automatically control program of painting robot.