Endothelial Cell Image Enhancement using Decimation-Free Directional Filter Banks

The enhancement and binarisation of boundary structure in an endothelial cells image is a vital task for measuring the cell density and degree of hexagonality. Endothelial cells images acquired by a non-contact specular microscope usually suffer from spatially varying brightness, and noisy background. Since the cell image contains boundaries which are predominately linear with various directions. Therefore, the paper proposes directional filter bank to isolate various directional features in the presence of noise. In order to combat non-uniform illumination, the DFB has a pre-processing step of bandpass filters. The combined system has effectively reduced the non-uniform character and noise, while accentuating the linear features. The quality of the results shows promise and proves the effectiveness of our proposed system