This paper proposes an algorithm of image retrieval from a partial request. In order to retrieve images containing a specific object or group of objects, we use an algorithm of inexact graph matching, adapted to adjacency graphs of regions. The number of regions representing the object can be different from an image to the other. The algorithm uses a search tree in which only similar nodes are developed. The adjacency and spatial relationship of regions are used to prune the tree and accelerate the retrieval. The algorithm computes a distance between graphs, allowing to rank images. This distance takes into account both the distance between region features and the relative position of regions