In order to improve the realism of the simulated scene, weathering the objects of the image is an effective method. Using an image processing method to achieve the fine weathering effect of the objects surface in the image. First of all, use the radial basis function (RBF) method to calculate the weathering degree image. Even if the color of the surface of the object changed greatly, the algorithm could calculate the degree of weathering more accurately. Then, use the image segmentation algorithm to extract the most weathered region as the "weathering exemplar". Finally, the patchmatch image repair algorithm was used to complete the "weathering exemplar", so that the "weathering exemplar" could be propagated seamlessly in the weathering area of the image. The results show that the proposed method can generate various types of weathering effects. Using the method of exemplar propagation can better simulate the weathering image.

The KNN classification algorithm is nonparametric, easy to understand and relatively efficient, and is widely used in many fields. In the traditional KNN algorithm, the Euclidean distance method considers the contribution of all the attributes of the sample as the same. But in fact, the contribution of different attributes of the sample is not necessarily the same. To solve this problem, an improved KNN algorithm based on analytic hierarchy process is proposed. In the improved algorithm, firstly, the weights of each attribute of the sample are calculated by using the analytic hierarchy process, and then the sample distance is calculated by using the weighted Euclidean distance, thereby classifying according to the weighted distance. In the experiment, with the increasing number of training samples, the efficiency of AHP-KNN algorithm is improved, and it is gradually better than the efficiency of the FCD-KNN algorithm and the traditional KNN algorithm. The simulation results show that the improved algorithm proposed can effectively improve the classification accuracy of the traditional KNN algorithm, and has certain theoretical and practical value.