Paper
2 February 2004 Removal of aliasing effect on MTF measurement using bi-resolution images
Author Affiliations +
Abstract
One method to assess in-flight Modulation Transfer Function (MTF) relies on couples of images of the same landscape acquired with two spatial resolutions. The higher resolution image stands for the landscape and the ratio of the spectra gives the lower resolution instrument MTF. The main drawback of this method is the sensitivity to aliasing. This papers begins with a brief recall of the method putting the stress on the theoretical basis of the aliasing. The next step presents a way of aliasing correction when an MTF model is available. If it is not the case, the correction will be limited to the surrounding of the Nyquist frequency. This correction is applied to a test couple made with an airborne image of Toulouse and a simple simulation. The lower resolution image is obtained by the convolution of the airborne image with a large triangular function so that the ratio of the pixel sizes is equal to 10. The choice of 10 comes from the available couples of real images planned to be processed. For this test couple the MTF model is a simple sinc2. The first results are quite noisy. The analysis of the magnitude and phase of the high resolution image spectrum shows that the landscape spectrum behaves like an 1/f function in the interesting low resolution frequency domain and the phase behaves like a Gaussian random variable. This is used to improve the correction and obtain good results. Correction is then applied on the available couples of images leading to SPOT4 HRVIR and VEGETATION MTF measurements.
© (2004) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Francoise Viallefont-Robinet "Removal of aliasing effect on MTF measurement using bi-resolution images", Proc. SPIE 5234, Sensors, Systems, and Next-Generation Satellites VII, (2 February 2004); https://doi.org/10.1117/12.507273
Advertisement
Advertisement
RIGHTS & PERMISSIONS
Get copyright permission  Get copyright permission on Copyright Marketplace
KEYWORDS
Lawrencium

Modulation transfer functions

Vegetation

Image resolution

Sensors

Convolution

Image processing

RELATED CONTENT

Automatic MTF measurement through a least square method
Proceedings of SPIE (November 04 2004)
Image Resolution Limits Resulting From Mechanical Vibrations
Proceedings of SPIE (December 23 1985)
SPOT5 MTF measurement using biresolution images
Proceedings of SPIE (November 04 2004)
In-flight AHS MTF measurements
Proceedings of SPIE (October 09 2008)
Vegetation MTF in-flight measurement using HRVIR
Proceedings of SPIE (November 15 2000)

Back to Top