In the near-infrared (NIR) light imaging manner, finger-vein images are always degraded greatly due to optical scattering in the biological tissue. This directly leads to difficulty in reliable finger-vein feature representation. To deal with the problem of finger-vein image degradation, this paper proposes a simple but effective image enhancement method based on scattering removal. First, according to the light propagation in biological tissue, a specific optical model is introduced to characterize the intensity of degraded finger-vein image as a linear combination of attenuation component and scattering component. By means of a regularization solution, the scattering component is then estimated to solve the optical model, and thereby the enhanced finger-vein image can be obtained. Finally, experimental results demonstrate the validity of the proposed method in contrast improvement for finger-vein images.
Yang, J., Zhang, B., & Shi, Y. (2012). Scattering removal for finger-vein image restoration. Sensors, 12(3), 3627–3640. https://doi.org/10.3390/s120303627