19. A video summarization system, suitable for extracting a plurality of key frames and a plurality of key sentences from a video to form an abstract wherein the video comprises a plurality of sentences and a plurality of frames, the video summarization system comprising: a similarity computing apparatus, used for computing the similarity between each frame to obtain a plurality of similarity values; a key frame extracting apparatus, used for choosing the key frames from the frames wherein the sum of the similarity values between the key frames is minimum; a feature space mapping apparatus, used for converting the sentences into a plurality of corresponding sentence vectors and computing the distance between each sentence vector to obtain a plurality of distance values; a clustering apparatus, used for dividing the sentences into a plurality of clusters according to the distance values wherein the clusters are members of a set, and the clustering apparatus further computing the importance of each sentence of each cluster to obtain the importance of each cluster and applying a splitting step to split a most important member with the highest importance in the cluster into a plurality of new clusters, wherein the new clusters replace the original most important member and join the set as members of the set; and a key sentence extracting apparatus, used for choosing at least one key sentence from each members of the set, wherein the sum of the importance of the key sentences is maximum.
25. The video summarization system according to claim 19 , further comprising computing the importance of each sentence of the new clusters to obtain the importance of each new clusters after the clustering apparatus proceeding the splitting step.