| Virtual Reality (VR) is an advanced computer user interface. Virtual Reality Technology (VRT) includes computer graphics, human-computer interaction, sensor technology, artificial intelligent technology and other advanced technologies. Its application can greatly reduce people's burden and improve work efficiency. It is important to make an in-depth study of VRT and its applications.The definition and characteristics of VR are. discussed in this paper, following its applications in psychotherapy especially. It also analyzes the need and feasibility of VR in psychotherapy. Then a psychotherapy assistant system based on VR is designed under MFC. The system uses real-time image processing technology and vibration device to create a feeling of immersion in a virtual environment. It can extract human bodies from real world and put into the virtual environment real-timely. The process of image processing is designed with pipeline structure, which ensures the video processing real-time.The main process starts with real-time human body video acquisition using VFW. The image processing unit processes the video stream frame-by-frame. It turns the current frame to binary image by Frames Difference, extracts parameters according to pixels' information and the characteristics of human body, in order to identify the target region directly. To improve the extraction quality, mathematical morphology is introduced in dealing with binary image. So the binary information is corrected to be more accurate. In the basis of the binary image, body image could be combined with the virtual picture frame by frame to form a new virtual video, including real person image and virtual background. At last, use median filter method to smooth the output video frame. The main function is to reduce the lays of frames. In the aspect of interaction, the system can recognize the motion by pixels' change, while inform guide the patient by interactive vibration device during the cure process. The vibration device receives the action signal through serial port, and decodes it by MCU. Then transmit to remote shock motors by wireless module based on PT2262/2272. With the help of interaction, people can feel realistic by seeing synthetic video in VR glasses.The experimental result shows that the pipeline structure makes the system effective and real-time, as well as the body extraction according to binary parameters instead of complex color image information. And the final smooth processing makes the output natural. Furthermore, the wireless vibration device's design makes people's movement free, and the virtual experiencing better. In general, the whole system processes images fast and interacts well in human-computer interaction. It meets the request of VR psychological. |
