Abstract

Panoramic image technology provides new facilities for the presentation of cultural heritage recordings. Image based visual reality is an approach for documentation of monuments and sculptures avoiding the time consuming modeling process needed for a geometric model. The technology is not limited to existing objects, it can be used for virtual reality models as well. Plug-ins for Web browsers like Apples QuickTime or the LivePicture Viewer provide unlimited interactive access.
Single images taken from a fixed position while rotating the camera have to be stitched together. Warping onto a cylinder surface or sphere surface results in the spatial imagination the user gets while navigating through the model at the comuter screen. A photo object is created by moving the camera around the object with a fixed target point. Those objects can be turned around by dragging the mouse. Authoring tools are available for the description of complete scenes. Those scenes can be interactively entered by visitors.

1. Methods and Cameras for Producing Panoramas

There are five basic techniques for producing panoramas. The conventional method crops the image to a long format. When the negative is printed it looks like a long narrow panorama but the field of view is still unchanged. The APS cameras today provide such an imagination.
A series of images taken with a rotating exposure direction and displaying the photos next to another is the oldest method to show a wide filed of view. The advantage of digital image technology makes the segmented method very popular today. Taking the photos with a digital camera enables an automated process to display scenes for interactive viewing.
Field of views up to 180 degree can be photographed with a swing-lens camera. The lens is mounted in a rotating cylinder while the film plane is curved. During exposure the lens rotates and paints the image through a slit onto the film. A camera of this type is the Noblex manufactured in Germany,

The rotational method needs a camera which can rotate about 360 degree while the film turns synchronously opposite to the camera rotation. This technique is still very popular. An advantage is, that moving objects can be recorded without any problems. While taking street scenes with the segmented method, people or cars can occur more times in different positions. The Roundshot camera from Switzerland is state of the art of rotating cameras. The Noblex and the Roundshot cameras are both using 220 film. It has to be mentioned that the use of those expensive panoramic film cameras needs special film scanners for digitizing. A much cheaper solution is the use of a digital camera with segmented image order. Especially suited for the needs of media profession and Internet presentation the PanoCAM DPC-10 from Spheron VR is designed to capture 360 degrees shots of its surrounding by rotating the camera . The image is captured by a CCD , giving a digital panorama without intermediate procedures like stitching. The camera is computer controlled . With the PanoCam Server software panoramas can be taken in predefined intervals and stored on a Web server, from where they are distributed. Maximum resolution of a 360 degree shot is 1350x9000 pixel.