Low Light Hyperspectral Imaging Using HDR Methods

Hyperspectral imaging provides spectral information for every pixel in an image, though the data is less reliable for low levels of illuminance. Merging hyperspectral imaging with High Dynamic Range (HDR) imaging can improve the loss of accuracy in low-lit environments by compensating for dark pixels with high exposure values. A study involving a light-booth with a maximum of 135 cd/m(2) shows a significant improvement in spectral and photometric accuracy of the spectral data using HDR techniques. The sRGB image quality also improves significantly. The HDR merging method using a mean or median value of valid pixels also significantly improves results as compared to the first correct pixel. The results from this study provide a promising outlook for the use of hyperspectral imaging in poorly lit scenes and should be further investigated.