基于双目视觉和主动光源的河工模型三维地形测量方法

Binocular-stereo Method for Measuring Bed Topography Under Meshing Illumination

针对河工模型三维地形测量需要,提出了一种基于双目视觉和主动光源的非接触多点测量方法.首先,利用传统的DLT模型(Direct Linea Transformation)估算图像主点坐标,再借助考虑畸变矫正逐步补偿的非线性优化方法标定出相机的内外参数;其次,通过图像形态学处理提取点阵光斑的质心坐标,根据定位光斑与其余光斑的位置关系精确匹配出左右两幅图像中的同名斑点;最后,利用超定线性方程组计算点阵光斑的三维坐标,插值重构出河工模型的三维地形图.该方法装置简单,测量速度快,测量精度达0.2mm,具有良好的推广前景.

Bed topography measurement plays a crucial role in hydraulic model experiments. This study presents a new method to achieve such measurement based on binocular-stereo vision and structured,meshing illumination. The instrumentation includes three major steps,namely,calibration of camera parameters,identification and matching of marker points,and reconstruction of target topography. The first step entails estimating the principal point’s pixel coordinates with a DLT model and calibrating the parameters of the camera through distortioncorrection based nonlinear optimization. The second step establishes the correspondence between two cameras to identify each marker in terms of their central coordinates obtained through image analysis. The third step concludes the measurement by solving the overdetermined linear system to reconstruct the target three-dimensional topography. Simple,efficient,and accurate( measurement uncertainty 0. 2mm),the new method shows promise as being a reliable tool for topography measurement.