Parallel Image Stitching of Airborne Imagery.
R. Kooper and P. Bajcsy
NCSA, University of Illinois at Urbana-Champaign, Urbana, USA
IS&T/SPIE Electronic Imaging 2011 San Francisco, CA, January 23 - 27, 2011
This paper addresses the problem of stitching Giga Pixel images from airborne images acquired over multiple flight paths of Costa Rica in 2005. The set of input images contains about 10,158 images, each of size around 4072x4072 pixels, with very coarse georeferencing information (latitude and longitude of each image). Given the spatial coverage and resolution of the input images, the final stitched image is 294,847 by 269,195 pixels (79.3 Giga Pixels).
Our approach is to utilize the coarse georeferencing information for initial image grouping followed by an intensity-based stitching of groups of images. This group-based stitching is highly parallelizable. The stitching process results in image patches that can be cropped to fit a tile of an image pyramid frequently used as a data structure for fast image access and retrieval. We report our preliminary experimental results obtained when stitching and pyramid tiling a 4 Giga Pixel image from the input images at one fourth of their original spatial resolution using a single core on our eight core server. As the processing requires parallel computing approaches in order to generate the full resolution image, we are collecting actual benchmarks on parallel hardware platforms.