In this paper a novel system for image replica detection is presented. The system uses color-based descriptors in order to extract robust features for image representation. These features are used for indexing the images in a database using an R-Tree. When a query about whether a test image is a replica of an image in the database is submitted, the R-Tree is traversed and a set of candidate images is retrieved. Then, in order to obtain a single result and at the same time reduce the number of decision errors the system is enhanced with Linear Discriminant Analysis (LDA). The conducted experiments show that the proposed approach is very promising.