Selective noise removal method in low frequency region for fiber bundle-based endoscopy

This paper introduces the restoration method of degraded images distorted by inherent structure of fiber bundle. The criterion considered for the restoration is based on morphological processing and notch filter, removing the particular frequency, with auto peak detection. The proposed algorithm achieved effective removal of pixelated artifact such as regular honeycomb pattern by finding particular peaks in Fourier domain. As a series of procedure, we have found optimized parameter for decoupling the noise. Experimental results of contrast-to-noise ratio (CNR) demonstrate numerical enhancement from 3.9dB to 16.7dB. Our proposed method can also be expected to apply other periodic pattern noise.