Synthesis and processing of remote sensing images
Through false-color synthesis of remote sensing images, image effects under different combinations were analyzed, and interpretation was made of ground objects that can be distinguished based on historical data. By relying on the shape and image features of ground objects, most of the ground objects in the study area can be distinguished. For example, river courses, reservoirs, farmlands, residential blocks, etc. can be easily identified on the synthetic remote sensing images.
Remote sensing TM4 band is a near-infrared wave band in which vegetation shows strong reflection, TM3 band corresponds to the area for absorption of vegetation chlorophyll, TM2 band corresponds to the area of green reflection by healthy vegetation. Therefore, the three bands can reflect vegetation information to some extent. One major distinction between a built-up urban area and a suburban area is that built-up urban area shows less vegetation biota while suburban area shows abundant vegetation biota. As a result, synthetic technique and enhancement technique for remote sensing images can be employed, and TM4, 3 and 2 images can be integrated with Red, Green, Blue-synthesized false-color images, and the synthetic images can be treated with extension and marginal enhancement. In the final remote sensing images, the built-up urban area will be represented by light gray or gray, and vegetation will be represented by red. Therefore, built-up urban areas will be distinguished from suburban areas by distinct boundaries between them, so the built-up urban areas can be well identified from the images.