應用JPEG-2000於航空影像壓縮

Abstract

應用JPEG2000於航空影像壓縮 學生：吳鴻謙 指導老師：史天元 交通大學土木工程學系 摘要 本研究針對JPEG2000影像壓縮格式應用於數值航空影像。以主觀評比、客觀影像品質指標（如SNR、PSNR、RMSE、Entropy、平滑化與銳化指標）和DSM匹配成功率，比較JPEG與JPEG2000影像壓縮格式對數值航空影像的影響。接著針對JPEG2000影像壓縮格式，在不同影像內涵物的情況下是否會有不同的影響。最後對不同壓縮比的航照影像，以商業軟體生成DSM，比較其DSM匹配成功率。 實驗影像是以民國九十年在竹北地區所拍攝的五千分之一的黑白航空影像，DSM生成軟體則是以PCI Geomatica OrthoEngine所生成，JPEG2000影像壓縮格式，則是以JasPER所產生。 經實驗發現壓縮率大於30，JPEG2000比JPEG更能提供良好的影像品質；且對影像影響的程度較JPEG小，能夠提高DSM匹配成功率。不同影像內涵物對JPEG2000壓縮也會有不同的表現。

Using JPEG2000 in Aerial Photo Compression Student：Houn-Chien Wu Advisor：Tian- Yuan Shih Department of Civil Engineering National Chiao Tung University Abstract In this study, the performance of JPEG2000 is evaluated for aerial photo image compression. First, evaluation is performed on the full scene of the photos based on visual analysis and some indices are computed for different ratios with both JPEG2000 and JPEG, including SNR, PSNR, RMSE, Entropy, etc. Second, some objects selected in the scene are studied. Finally, the effects of different compression ratios of JPEG2000 on DSM auto-matching procedure are evaluated by using a commercial software. We can conclude from this study, that when the compression ratio is greater than 30, JPEG2000 can provide better image quality than JPEG can. The image quality indices of JPEG2000 will vary based on the content of JPEG2000. Compared to JPEG, the JPEG2000 has less influence on the image quality and increases the matching ratio for DSM production.