## 5 Results and Discussion  
### Image Enhancement Results  
#### 5.1.1 Oif  
Due to the spectral mixing effect and fuzziness of spectral features in low spatial resolution of satellite images, for the lithological interpretation of WV-2 data, we assigned more weight to visual inspection and interpretation to establish interpretation signs. We took full advantage of its spatial resolution and avoided the disadvantage of its narrow spectral range. For visual interpretation, the difference between hues is the most significant and intuitive. Based on the data correlation analysis of WV-2, it can be known that the optimal index value for the combination of b8, b6, and b4 is the largest (Table 2), and selecting these three bands is more conducive to the interpretation of lithology and structure. However, in actual remote-sensing interpretation, other combination schemes can also be used, such as selecting b5-b3-b2 for true color synthesis to make the image closer to natural colors, or selecting b7-b5-b3 for standard false color to show vegetation in characteristic red. Sedimentary rocks in the area are mainly composed of compound conglomerate, sandstone, siltstone, and significant banded texture structure is a typical remote-sensing interpretation sign [62]. Combined with the comprehensive characterization of rock texture and hue, the identification and delineation of sedimentary rocks in the study area can be achieved. At the macroscopic scale, conglomerate is characterized by multiple steep slopes, with large terrain undulations, underdeveloped water systems and vegetation, and rough texture (Figure 4a). Sandstone generally exhibits a more typical parallel banded texture on high spatial resolution images, with relatively delicate image features distinguishing it from conglomerate (Figure 4b). As a microclastic rock, siltstone appears delicate and soft in the WV-2 image. The WV-2 of b5-b3-b2 in RGB separated siltstone into brown-yellow, black-gray, and gray-brown (Figure 4c). Because this type of rock has poor water permeability,typical branched water system textures can be seen in the WV-2 image, and the vegetation is relatively developed. Most metamorphic rocks are characterized by relatively uniform hue and monotonous and directionally arranged discontinuous textures [62]. Common metamorphic rocks in the area include slate, quartz-magnesite rocks, and marble. The Upper Triassic slate is the most common metamorphic rock in the study area and has obvious interpretation signs. Due to the low degree of metamorphism in slate, it retains many features of microclastic rock, with finer residual slope sediments and low gentle hills or hill-like terrain (Figure 5b). The hue is mainly gray or black, and the distribution is mainly in the northeast part of the study area (Figure 5a). The boundary between the quartz-magnesite rock and the slate is neat, intermittently exposed along the southern boundary of the ophiolite body, and the north part of it is strongly developed with serpentinization (Figure 5c). The interpretation sign of marble is similar to carbonate rocks. In this article, the WV-2 true color synthesis of b5-b3-b2 in RGB with grayish and light colors as the main hue, with many speckled texture features, steep terrain, and retaining the basic characteristics of limestone (Figure 5d). The mantle perioditites crop out in a broad band along part of the ophiolite and make up the bulk of the ophiolite; harzburgite accounts for 70% of the Luobusa mantle peridotite [1]. The interpretation and delineation of ultramafic rocks using high-resolution remote-sensing images are more based on comprehensive analysis and judgment. Most of the chromitite bodies in Luobusa are located in the harzburgite; we focus on mantle perioditites closely related to chromite deposits. The harzburgites are locally deformed and serpentinized, particularly those in the eastern part of the ophiolite. Alteration increases slightly near the chromitite orebodies, and both serpentinite and tectonic precies are locally present [1].