Change detection is one of the most challenging issues when analyzing remotely sensed images. It consists in detecting alterations occurred in a given scene from images acquired at different time instants. Archetypal scenarios for change detection generally compare two images acquired through the same kind of sensor, i.e., with the same modality and the same spatial/spectral resolutions. This talk will address the problem of detecting changes between images of different resolutions or modalities. We will show that this challenging task can be tackled from a fusion perspective.