1. A computer-implemented method, comprising: learning representative land features, by a computing system, from multi-band images comprising image data to form a learned dictionary {g m }; computing a sparse representation with respect to the learned dictionary; clustering features of the sparse representation of the image, by the computing system, into land cover categories; performing land cover classification and change detection in a sparse domain, by the computing system, after the image is clustered; and outputting results of the land cover classification and change detection in the sparse domain, by the computing system.