Error of the slanted edge method for measuring the modulation transfer function of imaging systems

Abstract

The slanted edge method is a basic approach for measuring the modulation transfer function (MTF) of imaging systems; however, its measurement accuracy is limited in practice. Theoretical analysis of the slanted edge MTF measurement method performed in this paper reveals that inappropriate edge angles and random noise reduce this accuracy. The error caused by edge angles is analyzed using sampling and reconstruction theory. Furthermore, an error model combining noise and edge angles is proposed. We verify the analyses and model with respect to (i) the edge angle, (ii) a statistical analysis of the measurement error, (iii) the full width at half-maximum of a point spread function, and (iv) the error model. The experimental results verify the theoretical findings. This research can be referential for applications of the slanted edge MTF measurement method.

Improved Slanted Edge Methods of Measuring Modulation Transfer Function Based on Structured Total Least L1-, L2-norm Edge Fitting for Urban Remote Sensing Images

“…Qin and Gong proposed a slanted edge method to calculate the point spread function (PSF) of remote sensing images. (8) Xie et al analyzed in detail the factors that may affect the MTF results in the slanted edge method, (9) such as the edge angle and measurement error. The slanted edge approach generally includes four steps: (1) Edge extraction: The least squares (LS) method is usually adopted to calculate the slanted edge using the edge points.…”