A review of remote sensing image fusion methods

The recent years have been marked by continuous improvements of remote sensors with applications like monitoring and management of the environment, precision agriculture, security and defense. On the one hand, the high spectral resolution is necessary for an accurate class discrimination of land covers. On the other hand, the high spatial resolution is required for an accurate description of the texture and shapes. Practically, each kind of imaging sensor can only focus on a given different operating range and environmental conditions, the reception of all the necessary information for detecting an object or classifying a scene is not possible. So, for the full exploitation of multisource data, advanced analytical or numerical image fusion techniques have been developed. In this paper, we review some popular and state-of-the-art fusion methods in different levels especially at pixel level. In addition to reviewing of different fusion methods, varied approaches and metrics for assessment of fused product are also presented.