A recursive Otsu-Iris filter technique for high-speed detection of lumen region from endoscopic images

In this paper, a hardware efficient technique to segment the lumen region from endoscopic images is presented. It is based on applying the combined Otsu-Iris filter operations recursively. The proposed technique applies the Otsu's procedure recursively to obtain a coarse region of interest (ROI), which is then subjected to an Iris filter operation so that a smaller enhanced region can be identified. This enhanced region is subjected to the Otsu's procedure recursively and the process of performing Iris filter operation is repeated as before. It has been shown that by repeating this Otsu-Iris filter combination in an iterative manner facilitates in the rapid identification of the lumen region accurately. It has been shown that the proposed method substantially reduces the number of computations of Otsu's procedure when compared with the APT-Iris filter method. Finally, unlike the APT-Iris filter method, it does not require the precomputation of the cumulative limiting factor, which is highly dependent on the complex endoscopic images.