Student: 蘇俊嘉 Advisor: 歐陽明

This thesis presents an image-based 3D object viewer system for environment walk-through. The major advantage for image-based systems is that the rendering time is independent of the complexity of the scene. Thus, image-based systems are suitable for real-time applications. Some image-based walk-through systems are proposed in recent years, such as “QuickTimesymbol 210 \f "Symbol" \s 12牂 VR” of Apple Computer and our “Photo VR.” However, the common problem of image-based walk-through systems is that the freedom of the user is restricted, thus it is hard or almost impossible for the user to clearly observe a certain object within the scene from different view directions. To solve this problem, we propose an object viewer, which is used to represent a certain object with image-based techniques. With this system, the user can interactively observe an object from different directions in real time, as he moves or rotates the object by his own hands.

Our method is to get images of an object from some pre-selected view directions. Then intermediate images are interpolated from these source images using manually-selected matching features. The actual display sequence contains both the source images and the intermediate images. To build up an object model file for the object viewer, we must remove the background of the source images, mark up the matching features, and solve the occluding area problem of interpolated intermediate images.

We implemented the system on Windows 95 as a stand-alone application and as a Win 32 plug-in module for Netscape Navigator. In both cases, the performance is about 15 frames per second with interpolated intermediate images and is 25 frames per second without them. We also implemented some authoring tools that can be used to remove the background of the source images and mark up the matching features. With these authoring tools, the user can easily construct the object model file. The object viewer combined with Photo VR will form a general purpose walk-through system, which is suitable for applications, such as the virtual mall, on Internet.