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Proceedings Paper

Effect of pixel size and compression on metric quality of digital aerial images
Author(s): Juha Jaakkola; Eija Honkavaara
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Paper Abstract

The effect of memory space reduction methods on metric quality of digital aerial images has been investigated. The methods used to reduce the data volume are increasing the pixel size and compressing the image by JPEG and ALP (adaptive Laplacian pyramid). Metric image quality was investigated on different objects using different measuring methods. The quality was examined by defining absolute errors and relative changes of the images. Choosing the pixel size, compression method, and compression ratio depends on the application. Important factors to be noted are the required accuracy, measuring method, and the size and type of the objects to be measured. On the test data (7.5 micrometers images) the pixel size could be doubled to 15 micrometers and compression ratio 1:10 used without any remarkable effect on the metric quality of the image. For most photogrammetric applications the pixel size 15 - 30 micrometers would be appropriate. When reduction was 1:1...1:10, compression methods caused smaller distortions than increasing the pixel size. However, when the reduction was bigger, the optimal result was achieved using larger pixel size and light compression.

Paper Details

Date Published: 17 August 1994
PDF: 7 pages
Proc. SPIE 2357, ISPRS Commission III Symposium: Spatial Information from Digital Photogrammetry and Computer Vision, (17 August 1994); doi: 10.1117/12.182908
Show Author Affiliations
Juha Jaakkola, Finnish Geodetic Institute (Finland)
Eija Honkavaara, Finnish Geodetic Institute (Finland)


Published in SPIE Proceedings Vol. 2357:
ISPRS Commission III Symposium: Spatial Information from Digital Photogrammetry and Computer Vision
Heinrich Ebner; Christian Heipke; Konrad Eder, Editor(s)

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