This paper describes the system calibration and demodulation procedures used in an investigation of the scatter-specific tissue contrast that can be obtained by high spatial frequency (HSF) domain imaging and cross- polarization (CP) imaging using an inexpensive color imaging system.
HSF and CP imaging methods are both known to alter the reflectance image sensitivity to diffuse multiply- scattered and superficially backscattered photons. This results in enhanced contrast, compared to standard wide-field imaging, based on tissue surface microstructure and composition. Measurements in tissue-simulating optical phantoms show that CP images display contrast based on both scattering and absorption, while HSF is specifically sensitive to scatter-only contrast, strongly suppressing absorption-based contrast. By altering the frequency used, the degree of contrast suppression or enhancement can be tuned.1 This suggests that an inexpensive HSF imaging system could have potential to aid diagnostic procedures, where CP is the current state-of-the-art imaging modality.