FIAS3: Frame Importance-Assisted Sparse Subset Selection to Summarize Wireless Capsule Endoscopy Videos

Wireless capsule endoscopy (WCE) is a recently developed tool that allows for the painless and non-invasive examination of the entire gastrointestinal (GI) tract. The microcamera captures a large number of redundant frames for each WCE examination such that a video summarization technique is needed to assist in diagnosis. However, prevalent methods of summarizing WCE videos focus only on the representativeness of the frames owing to a lack of high-level information on their importance. This paper develops a Frame Importance-Assisted Sparse Subset Selection model, called FIAS3, to integrate the high-level frame importance from networks into a sparse subset selection model. The FIAS3 is optimized under three constraints: 1) a frame importance matrix to help pay more attention to important frames, 2) a sparsity constraint to make video summaries more compact, and 3) a similarity-inhibiting constraint to reduce redundancy. The results of experiments on a public dataset demonstrated that our FIAS3 outperforms other methods of summarizing WCE videos. Specifically, its coverage and video reconstruction error were 92% and 0.143, respectively, at a 90% compression ratio, recording respective at least 16.9% and 0.031 improvements over other methods. The results of generalization experiments showed that FIAS3 also achieves competitive results on private datasets.