解算的主要目的是将全方位图像还原成无畸变的图像。本文根据双曲面折反射全景视觉系统成像特点,提出了一种基于前向映射的全方位图像解算的改进算法。该算法首先采用前向映射空间变换方法将全方位图像的像素映射到虚拟观察平面上,然后利用改进的Shepard散乱数据插值法复原完整的解算图像,从而避免了在畸变的全方位图像中直接插值引起的图像解算的失真。实验结果表明,该方法不但消除了全方位图像的非线性畸变,而且提高了插值精度和图像灰度曲面的光滑性,使解算图像更接近真实景象。
The main aim of unwrapping processing is to transform omni-directional images into undistorted ones. An improved unwrapping processing method is brought forward based on forward mapping and the imaging feature of hyperboloidal catadioptric panoramic vision system. Firstly, the pixels of the omni-directional images are mapped to the virtual observation plane, and then unwrapped image is restored by using the modified Shepard scattered data interpolation method, which avoids distortion induced when interpolation is applied in the omni-directional image directly The experimental results indicate that the improved method is an effective cure for the nonlinear distortion of omni-directional images as well as effective promoter for the smoothness of gray surface and precision of interpolation, bringing more natural result.