Method for estimating modulation transfer function from sample images

Rino Saiga; Akihisa Takeuchi; Kentaro Uesugi; Yasuko Terada; Yoshio Suzuki; Ryuta Mizutani

doi:10.1016/j.micron.2017.11.009

Method for estimating modulation transfer function from sample images

Micron. 2018 Feb:105:64-69. doi: 10.1016/j.micron.2017.11.009. Epub 2017 Nov 22.

Authors

Rino Saiga¹, Akihisa Takeuchi², Kentaro Uesugi², Yasuko Terada², Yoshio Suzuki³, Ryuta Mizutani⁴

Affiliations

¹ Department of Applied Biochemistry, School of Engineering, Tokai University, Kitakaname 4-1-1, Hiratsuka, Kanagawa, 259-1292, Japan.
² Japan Synchrotron Radiation Research Institute (JASRI/SPring-8), Kouto 1-1-1, Sayo, Hyogo, 679-5198, Japan.
³ Graduate School of Frontier Sciences, The University of Tokyo, Kashiwanoha 5-1-5, Kashiwa, Chiba, 277-8561, Japan.
⁴ Department of Applied Biochemistry, School of Engineering, Tokai University, Kitakaname 4-1-1, Hiratsuka, Kanagawa, 259-1292, Japan. Electronic address: ryuta@tokai-u.jp.

PMID: 29179010
DOI: 10.1016/j.micron.2017.11.009

Abstract

The modulation transfer function (MTF) represents the frequency domain response of imaging modalities. Here, we report a method for estimating the MTF from sample images. Test images were generated from a number of images, including those taken with an electron microscope and with an observation satellite. These original images were convolved with point spread functions (PSFs) including those of circular apertures. The resultant test images were subjected to a Fourier transformation. The logarithm of the squared norm of the Fourier transform was plotted against the squared distance from the origin. Linear correlations were observed in the logarithmic plots, indicating that the PSF of the test images can be approximated with a Gaussian. The MTF was then calculated from the Gaussian-approximated PSF. The obtained MTF closely coincided with the MTF predicted from the original PSF. The MTF of an x-ray microtomographic section of a fly brain was also estimated with this method. The obtained MTF showed good agreement with the MTF determined from an edge profile of an aluminum test object. We suggest that this approach is an alternative way of estimating the MTF, independently of the image type.

Keywords: Microtomography; Modulation transfer function; Point spread function; Resolution.

Publication types

Research Support, Non-U.S. Gov't