Automatic Detection and Parameter Estimation of Ginkgo biloba in Urban Environment Based on RGB Images

Figure 5

Data processing: DSM: digital surface model; DTM: digital terrain model; CHM: canopy height model. The DSM and DTM are both types of digital elevation model (DEM) and represent the elevation distribution of the region. They differ in that the pixel values in the DTM are the ground elevation, whereas those in the DSM are the elevation of the top surfaces of trees, buildings, and other aboveground features. Since the urban bare ground is very flat and the DTM is created by interpolation, the elevation values everywhere in the DTM are similar, and the resulting image just appears uniformly gray.