Image Subset Union for Compressed Image Sets in Cloud Servers

Image deletion and image insertion, the current commonly used two kinds of image set management, refer to removing compressed images from and adding new photos to a compressed image set, respectively. However, they do not deal with well the problem of the combination of images selected from multiple compressed image sets. To address this issue, in this paper we first propose an image subset union algorithm for compressed image sets. Image subset union aims to integrate image subsets derived from multiple compressed image sets into a new compressed image set. First, we put forward a way to identify the root vertex candidate of the new compressed image set. Second, we classify all the images of image subsets into three categories: images needed to be re-encoded, images needed to be only decoded, and images unneeded to be re-encoded or decoded. Third, we also employ minimum spanning tree production, a proposed vertex layer candidate assignment method, depth- and subtree-constrained minimum spanning tree generation, as well as image re-encoding to build the new compressed image set. Experimental results show that our proposed algorithm can effectively accomplish image subset union with low complexity.