Small transparent testcharts for medical imaging applications
Most medical imaging applications are designed to capture images in a macroscopic or microscopic scale. Therefore the test charts have to be small.
Lighting can usually be controlled in machine vision. Therefore a standard contrast of 10.000:1 for the OECF chart is sufficient. But since the tonal levels are used for automatic detection and evaluation of elements in the image, it is helpful to get the OECF as detailed as possible.