2005) – High-Resolution Image Rectification and Mosaicing – A comparison between Panorama Camera and

The paper describes the acquisition and rectification of high-resolution images of a valuable stone mosaic in the city of Oldenburg. The piece of art is located on an outer wall of a school building, hence image recording had to be done under daylight conditions. We have used a 16 mega-pixel camera Kodak DCS 645M for the acquisition of nine overlapping images of the whole object. In addition, the panorama camera KST EyeScan M3 was used to acquire the complete mosaic in one scan. For the Kodak camera the image resolution in object space was about 0.6mm per pixel while the panoramic image yields 1.4mm per pixel. The geometric accuracy of the mosaic reconstruction is specified to about 2mm. Previous investigations have shown that the digital camera provides a geometric accuracy potential of better than 1:100000 if an appropriate camera model and calibration is available and well-defined point targets are used. The color quality of the camera is excellent. The geometric accuracy of the panorama camera is lower since the mechanical drives are less accurate and harder to calibrate. However, since the accuracy specifications of the project are not very high both cameras should provide a sufficient precision. The object is assumed to be flat within a few millimeters. A number of control points have been measured by theodolite observations. They are used to calculate image orientations and/or parameters for projective transformations. The images of the digital camera were processed individually, each resulting in a separate rectification with respect to a global object coordinate system. The panorama image could be oriented by space resection. The final image mosaic was then generated by stitching the separate image