一种基于单幅图像的树木深度估计与造型方法

Depth Estimation and Modeling of a Tree from a Single image

提出了一种基于单幅图像、利用光照引起的明暗效果（ｓｈａｄｉｎｇ）恢复树木枝干三维形态的方法，与传统ｓｈａｐｅ ｆｒｏｍ ｓｈａｄｉｎｇ技术相比，该方法根据树木的特殊结构，利用更稳定的明暗特征，取消了对表面、光源及拍摄条件的限制，从而将算法的鲁棒性提高到足以处理自然的树木照片．基于上述工作，提出了一种基于单幅照片的交互式树木造型方法，该方法避免用数学模型控制树木形态，独立于树木的具体种类，具有较高的普适性．由于取材于真实的自然树木，因而极大地提高了造型的真实感和自由度。

Recovering 3D shape of an object from one or a series of images is an interesting but challenging problem in both computer vision and computer graphics. Single--image based shape recovery techniques, as such shape from shading, need to make a number of assumptions, most of which can hardly be satisfied in a natural scene. This paper presents a new method that recover the 3D shape of branches from a single image. By making use of more stable shading characteristics due to the special structure of trees, it removes most of the restrictions in traditional shape from shading and thus, is robust enough to deal with pictures of nature trees. Furthermore, a method of modeling a tree from its single static image is proposed. In stead of defining branches with mathematical models, it directly extract branches from the image and reconstruct them in 3D space. As a result,the approach is not only Independent to the species of the tree, but also capable of producing more realistic models.