This paper advances and analyses an algorithm converting Raster to Quadtree. Both of the two data structures have their own advantages and disadvantages and suit different processes and operations for corresponding purposes. Raster is the most common structure for image data; and quadtree is a new data structure which has drawn more and more attention and has been developed very fast in recent years. The paper reviews the developing history of quadtrees

describes the converting algorithm and the base of it in detail. Furthermore

the algorithm is evaluated and analysed.