基于SLIC区域分割的三维地形重建算法

为利用无人机在高空连续拍摄的两幅航拍图像准确实现三维地形重建,提出了通过将图像进行区域分割来达到不同地形区域分别生成数字高程模型DEM数据的方法。首先利用简单线性迭代聚类SLIC超像素算法将图像分割为多个包含单一地形的超像素区域,再利用各区域的颜色信息进行相邻同类地形区域的融合,最后在所得的各区域内通过SIFT特征点提取与匹配、计算三维坐标来生成DEM数据。通过将重建地形结果与卫星地图对比表明,利用该方法能够有效实现地形重建;通过对比本文算法与传统地形重建算法的重建结果表明,利用该方法能准确呈现各地形间的边界信息。

A 3D terrain reconstruction algorithm based on SLIC segmentation

Most traditional 3D terrain reconstruction algorithms cannot represent the accurate structure of the terrain and are time consuming as well, thus the technological development is seriously hindered . In order to realize the 3D terrain reconstruction accurately by using pictures taken by unmanned aerial vehicle (UAV) with the advantages of high resolution, wide camera range and low demand of shot environment, we propose a method that generates digital elevation model (DEM) data respectively in different superpixel terrain areas by segmenting the images at the preprocessing stage. Firstly, the simple linear iterative clustering (SLIC) algorithm, which shows good performance in superpixel generation and is convenient to use, is adopted to segment the images into multiple superpixel terrain areas which contain just a single terrain type. Then the adjacent superpixel areas containing the same terrain are fused according to the LAB color information, in which way the number of superpixel areas is decreased and the speed of the algorithm is improved. Thirdly the scale invariant feature transform (SIFT) feature points’ extraction and matching are done in each area. Based on the matching results, the 3D coordinates are computed with the method of binocular stereo vision and DEM data are generated in the end to reconstruct the terrain. Comparing with the satellite map, the proposed algorithm can reconstruct 3D terrains effectively, and it can present the boundaries information accurately in contrast with traditional 3D terrain algorithms.