像方和物方结合的线阵卫星核线影像生成方法

An epipolar image generation approach combined object-based and image-based method for linear array satellite imagery

针对线阵卫星影像核线纠正问题,本文简要分析了现有方法的优劣势,并在此基础上提出一种将基于像方和物方相结合的核线纠正方法。其分为两步:首先在影像空间内对左影像进行分块并逐区域纠正,利用局部仿射拟合的方法实现左影像的核线纠正;然后利用物方投影基准面生成与左影像分辨率一致的右核线影像。试验结果表明,本文方法既能获取上下视差接近于零且优于对比方法的核线影像产品,又能够保证核线影像左右视差与高程的线性比例关系,尤其是3组较大核线曲率数据试验结果,证实了本文方法具有较好的稳健性和适用性,能够较好地应用到不同传感器的数据处理系统中。

Towards the issue of epipolar resampling for linear array satellite stereo-imagery,we analyze the advantages and disadvantages of the off-the-shelf methods.Then a new epipolar resampling approach that combines the Object-based and Image-based method is proposed.The approach has two steps.Firstly,the left epipolar image is resampled with the Image-based technique.Specifically,we divide the left original image space into several regular rectangular grid,then each grid is rotated independently to make epipolar direction parallel to the image line.After that resampling is achieved using local affine transform model.Secondly,both the right and left image are projected onto a datum plane in the object space to resample right epipolar image that has the same resolution as the left image.Experiments on five pairs of stereo pairs and comparison with the two prevailing methods show that the proposed method not only can obtain the epipolar image product with vertical parallax close to zero and superior to the comparative method,but also can guarantee the linear proportional relationship between horizontal parallax and elevation.In particular,the experimental results of three groups of larger epipolar line curvature data confirm that this method has good robustness and applicability,the proposed method could be well applied to different sensor data processing systems.