提出一种基于单幅图像的回转类锻件三维重建方法。利用图像中提取的锻件截面椭圆求解圆环点图像，并结合极线约束建立绝对二次曲线像的三参数约束方程，进而求取相机的内参数矩阵。利用平行截面椭圆间的平面投影特性，进行回转体表面经线和纬线的求解，进而通过对经线进行校正实现被测锻件形状的三维重建。利用拉盖尔(Laguerre)公式进行截面椭圆可见区域求解，提出了一种等弧长纹理采样方法，解决了传统纹理提取中纹理分辨率不一致的问题。实验结果表明，在只利用被测对象自身几何约束，不借助辅助标定设备条件下，形状重建及纹理映射结果较为有效。

A single-image-based three-dimensional (3D) reconstruction method of an axisymmetric forge piece is proposed. The imaged circular points are solved from two paralell cross sections extracted from the image. Combining with the epipolar constraint, the 3-parameter constraint equations of the imaged absolute conic are established and the intrinsic parameters are solved. The imaged meridian and latitude of the surface of the axisymmetric forge piece are extracted based on the planner projection characteristics between two paralell cross sections. Then 3D shape of the axisymmetric forge piece is reconstructed based on the corrected imaged meridian. The visible region of the cross section is computed based on Laguerre formula, and an equal-arc sampling strategy is proposed based on the extracted imaged meridian, solving the inconsistent resolution problem of conventional texture extraction algorithm. Experimental results indicate that the large axisymmetric forge piece can be reconstructed with its own geometrical constraint from sinlge image without any auxiliary calibration equipment and the reconstructed shape and effective texture can be obtained.