Quality evaluation of microscopy and scanned histological images for diagnostic purposes

Abstract

In this work we present a study for assessing and comparing the fidelity of biopsy and cytology images captured with two different devices, that is optical microscopes and scanners, at 40× magnification in bright field. The devices use different ways to magnify images. Microscopes use a set of lenses while scanners capture light through arrays of micro-photoreceptors. The objective is to carry out a quantitative evaluation to discern which of the two devices provides better image quality in terms of contrast, colour and stain. Since there is no unanimous consensus on quality metrics, we will make use of both an objective metric based on perceptual features, together with a subjective psychophysical test as the International Telecommunications Union (ITU) recommends in ITU-R BT.500 for such type of tests. Both techniques indicate a slight preference for the scanner over the microscope in terms of better image quality, considering defocus as the main problem followed by colour distortions. However, the image quality of both devices is suitable for clinical, educational and research purposes.