Image registration is an important operation in remote sensing applications that basically involves the identification of many control points in the images. As the manual identification of control points may be time-consuming and tedious several automatic techniques have been developed. This paper describes a system for automatic registration and mosaic of remote sensing images under development at the Division of Image Processing (National Institute for Space Research - INPE) and the Vision Lab (Electrical & Computer Engineering Department, UCSB). Three registration algorithms, which showed potential for multisensor or temporal image registration, have been implemented. The system is designed to accept different types of data and information provided by the user which speed up the processing or avoid mismatched control points. Based on a statistical procedure used to characterize good and bad registration, the user can stop or modify the parameters and continue the processing. Extensive algorithm tests have been performed by registering optical, radar, multi-sensor, high-resolution images and video sequences. Furthermore, the system has been tested by remote sensing experts at INPE using full scene Landsat, JERS-1, CBERS-1 and aerial images. An online demo system (http://nayana.ece.ucsb.edu/registration), which contains several examples that can be carried out using web browser, is available.