ANALYSIS OF JPEG2000 QUALITY IN PHOTOGRAMMETRIC APPLICATIONS
Andrea Biasion, Andrea Maria Lingua, Fulvio Rinaudo · PORTO Publications Open Repository TOrino (Politecnico di Torino) · 2005
The recording of a large amount of data required for high resolution digital images is a common problem in digital photogrammetric applications, where several digital images occur for each block. One solution could be, that of using compression algorithms (JPEG, ECW and now JPEG 2000) that allow an extremely large amount of image data to be compressed into a relatively small amount of data. Even the most recent compressor algorithms declare a lossless compression ratio, the most efficient are lossy (the compression of the image data decreases the geometric and radiometric quality information). The effects of the JPEG2000 compression algorithm on the geometric quality of compressed images is studied in this analisis. This evaluation has been made for the case of automatic and manual stereo plotting. In the first, an automatic Least Square Matching (LSM) collimation procedure was applied to the image of a calibrated grid (acquired with a DTP scanner at 700 dpi) at different compression ratios, and to the uncompressed grid image. The difference between the compressed and uncompressed image coordinates was evaluated. In the second case, a stereoscopic model made up of two aerial photos of the town of Pavia was oriented and used (coupled to several ratio compressed images), to extract the 3D coordinate values of a point set, and to evaluate the differences between the compressed and uncompressed images. The results were compared with those previously obtained by the authors with the JPEG and ECW algorithms