Title: Measurement and simulation data for "Identification of aliasing effects in measurements of unknown MTFs"
Authors: Schake, Markus, Physikalisch-Technische Bundesanstalt (PTB), Fachbereich 4.2, Bild- und Wellenoptik, ORCID: 0000-0002-9883-3494
Schulz, Michael, Physikalisch-Technische Bundesanstalt (PTB), Fachbereich 4.2, Bild- und Wellenoptik
Contributors: HostingInstitution: Physikalisch-Technische Bundesanstalt (PTB), ISNI: 0000 0001 2186 1887
Language:en
DOI:10.7795/710.20210915
Resource Type: Dataset / Simulation Data
Publisher: Physikalisch-Technische Bundesanstalt (PTB)
Rights: https://creativecommons.org/licenses/by/4.0/
CC-BY 4.0 International
Relationships: IsReferencedBy: DOI https://doi.org/10.1117/12.2601176
Dates: Available: 2021-09-15
Classifications: OCIS 110.4100 Modulation transfer function ; OCIS 040.1490 Cameras ; OCIS 120.4800 Optical standards and testing ; OCIS 220.6360 Lenses
File: Download File (application/zip) 1.46 GB (1571520504 Bytes)
MD5 Checksum: 30e4a6051daf87ef7e4c5fe1fc769a5d
SHA256 Checksum: 2cccce0bcf2a1654579bbe2154ddf4604afe1e44e7ad3db8e690b089607bf870
Keywords: optical transfer function ; line spread function ; cameras ; aliasing
Abstract: The provided data set and simulation software enables the immediate replication of the results presented in
"Identification of aliasing effects in measurements of unknown MTFs."
The research data is structured with respect to the figures presented in the contribution. Each subfolder contains all necessary measurement or simulation data to receive the figure from the contribution by running a MATLAB file. Therefore, it is possible to compare the results with full context to those presented in the contribution.
The simulations demonstrate the influence of aliasing on MTF measurements employing the slanted slit algorithm.
The measurement data saved as *.mat files contains the tilted slit images as recorded by the camera detectors.
Each set of measurement data contains the following variables:
-binning -> The pixel binning factor applied in the camera
-camera -> The name of teh camera device
-exptime -> The employed exposure time
-magnification -> The applied microscope magnification
-*image -> The recorded LSF images
The specimen under test is a calibration objective manufactured by Zeiss with infinite to finite imaging, a focus distance of f_s = 50mm and an f-number a_s = 4.
The following abbreviations are employed in the labeling of the subfolders:
MTF -> Modulation Transfer Function
Pco -> Refers to the camera model Pco Panda camera employed in the experiment
Bas -> Refers to the camera model Basler Ace 2 camera employed in the experiment
20x,10x,6.3x -> Refers to the magnification of the microscope objectives employed in the experiment

The experimental data is evaluated employing the slanted slit algorithm and shows the influence of aliasing and uncorrected influences from detector and objective characteristics on the MTF measurement.
The oversampling achievable by the slanted slit method is demonstrated to resolve the aliasing issues and provides a tool to identify and correct aliasing errors in unknown MTF measurements.
Other: description of the individual files:
Each subfolder refers to a figure in the contribution. Each folder contains a "HOWTO.txt"
file with instructions how to generate the graphical output of the measurement or simulation data.
The Figs.:
3-4 contain simualtion results
2,5-9 contain measurement results


Recommended software to open the data:
MATLAB R2016b, Python (https://docs.scipy.org/doc/scipy/reference/generated/scipy.io.loadmat.html)
- The simulation and data evaluation files are *.m files and require MATLAB to be executed. However, they may be opened in a text editor to view the code.
- The measurement data are stored as structs in *.mat files. These may be opened with MATLAB, but may also be imported into Python and transfered into alternative data formats like *.h5.

Acknowledgements:
We want to acknowledge the support of this project by Trioptics GmbH (Strandbaddamm 6, 22880 Wedel,Germany).
Funding: Trioptics GmbH (Strandbaddamm 6, 22880 Wedel,Germany), Other: http://d-nb.info/gnd/1079292799, Grant Title: MTF-Referenzmesstechnik