The unmanned aerial vehicle (UAV) image taken in foggy or haze weather usually has lower contrast and fidelity, the quality of the image is seriously degraded. In this paper, we propose a dehazing model based on dark channel prior to dehaze the UAV image. We use a quad-tree hierarchical searching method to estimate the atmospheric light value, it can effectively avoid the influence of white objects in the image on the estimation of atmospheric light values. In the process of refining the medium transmission map, we propose a new regularization optimization scheme. Experimental results show that the proposed approach effectively recover the clear UAV image.

The color of stainless steel surface is mainly determined by its own material or substance attached to the outer face of stainless steel. It can be roughly classified as follows: 1. Color of stainless steel itself or the unique outer surface color after physical processing such as polishing, frosting, drawing and sand blasting. 2. Attach a thin layer of other metals or alloys to the surface of stainless steel object with different chemical electrolysis principles to make stainless steel show specific color and promote the enhancement for corrosion resistance of stainless steel. 3. The outer surface of stainless steel is exposed to the natural environment, the metal (steel component) in contact with the air or natural environment (temperature, air, time, surface roughness, etc.), thus a layer of oxide will be oxidized on its surface, which tends to gradually become the same color. The characteristics of stainless steel include durability, little maintenance required, long service life, and scientific and modern appearance. The curtain wall of Science and Technology Museum of Start of Optics Valley is made of stainless steel, which also avoids light pollution caused by stainless steel surface to the surrounding environment. The architect performed physical sandblasting on exterior to form diffuse reflection on the surface. On the outer surface with countless tiny concave potholes of stainless steel after sandblasting, the change in stainless steel color of building exterior was caused by the change in angle and light of plates. In this regard, the changes in surface color of stainless steel were tried to improve by consulting relevant experts in stainless steel materials and performing a lot of related tests. This article includes detailed records and analyses of the process. Readers may therefore be inspired to avoid or solve similar problems in similar curtain wall with stainless steel surface.

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