Hyperspectral imaging of human hands and curvature correction

Hyperspectral imaging (HIS) is a non-contact and non-invasive method that provides spectral and spatial information in a single measurement. It has been recently introduced into the medical imaging as a research tool for determination of physiological parameters distribution (e.g., hemoglobin and oxygenation maps).
An imaged surface curvature significantly affects illumination distribution over the surface and thus introduces artifacts in the recorded HSI. Such artifacts markedly affect accuracy of the image analysis, therefore a curvature correction of the images should be performed. In this study, hands of human volunteers were imaged by a HSI system (400–1000 nm spectral range) and a laser triangulation profilomer (LTP) providing 3D surface of the hands. Lambert cosine law and height corrections were applied to the recorded images. The corrected images show improved illumination homogeneity, effectively eliminating the curvature artifacts.
By combining HSI and LTP, hyperspectral images can be successfully corrected for the curvature artifacts, greatly improving accuracy of the further image analysis (original image discrepancy 12 %, corrected image discrepancy 4 %).