Comparing MTDP and TOD for thermal imagers with boost

Triangle Orientation Discrimination (TOD) developed by TNO Human Factors and Minimum Temperature Difference Perceived (MTDP) developed by Fraunhofer IOSB are competitive measurement methods for the assessment of well and under sampled thermal imagers. Key differences between the two methods are the different targets, bars for MTDP and equilateral triangles for TOD, and the measurement methodology. MTDP bases on a threshold measurement whereas TOD uses a psychophysical approach. A former study compared MTDP and TOD for standard thermal imagers. It found that it is possible to transfer TOD to MTDP and vice versa using a sigmoidal transition function. If this is also valid when applying advanced signal processing remained open. To examine this, the study was now extended to boost filtered thermal imagers. Equipment in test was an under-sampled MWIR imager operating without and with five different boost filters, four different Laplace- and one Wiener-filter. Comparative MTDP and TOD measurements for these six configurations showed the validity of the derived sigmoidal transition function also for this type of signal processing. Conclusive, to date the comparison of MTDP and TOD gave no preference for one of the methods. They should result in comparable performance predictions, although it is generally not possible to rule out that there is advanced signal processing where one or both of the methods may fail.