Automatic frame reduction of Wireless Capsule Endoscopy video

Wireless Capsule Endoscopy (WCE) is a non-invasive colour imaging technique that has been introduced for the screening of the gastrointestinal tract and especially the small intestine. WCE is performed by a wireless swallowable endoscopic capsule that transmits more than 50,000 video frames per examination. The visual inspection of the resulting video is a highly time-consuming task even for the experienced gastroenterologist. In this paper we propose a novel WCE video summarization approach which is subsequently evaluated using real world patient data. The proposed approach aims to the reduction of the number of the video frames to be visually inspected so as to enable significant reduction in the video assessment time. It is based on clustering using symmetric non-negative matrix factorization initialized by the fuzzy c-means algorithm and supported by non-negative Lagrangian relaxation to extract a subset of video scenes containing the most representative frames from an entire examination. Real world patient data that display abnormal findings at several sites in the small intestine were annotated by expert gastroenterologists in order to experimentally evaluate the proposed approach. The results demonstrate that the suggested approach leads to significant reduction of the total number of frames in the input video without losing critical information related to the abnormal regions of the small intestine.