The　development　of　the　image-based　normalization　technique　used　for　Landsat　Thematic　Mapper/Enhanced　Thematic　Mapper　Plus　imagery　is　reviewed.　The　techniques　perform　radiometric　calibration　by　converting　the　digital　number　of　the　Landsat　imagery　to　at-satellite　radiance　and　then　to　at-satellite　reflectance　using　data　normalization　method.　The　validation　case　in　this　study　shows　that　the　illumination　difference　between　the　tested　multi-temporal　Landsat　TM　images　can　be　considerably　reduced　to　one-third　of　that　of　the　original　DN-based　image　through　the　normalization　technique.