This project presents the design and implementation of different techniques of Relevance Feedback for image searches. These techniques use the user interaction with the search results to estimate the importance of various search criteria in the request submitted by the user. The results have been performed through the linear combination of similarity measures of different MPEG-7 visual descriptors. The results of this project have been compared with those previously obtained in the Final Degree Project by Carles Ventura. For this reason the system has been evaluated with the reference database, MPEG-7 Common Color Dataset (CCD).