双层增强思路下激光雷达成像小目标精准检测方法

    Accurate detection method for small targets in laser radar imaging under the dual layer enhancement approach

    • 摘要: 在干扰环境中检测激光雷达成像小目标时,因复杂背景辐射引发的灰度级坍缩以及边缘轮廓淹没问题,致使小目标检测结果的准确性偏低。为此,本研究基于双层增强思路,提出一种小目标精准检测方法。在采集原始成像后,采用引导滤波将图像分解为基本层与细节层。基本层通过自适应引导滤波直方图映射压缩动态范围,以矫正灰度级坍缩,细节层则采用饱和处理抑制散粒噪声,并通过自适应增益调控恢复被淹没的边缘轮廓。两层经固定系数加权融合实现细节增强。然后,通过空间距离加权的方式改进局部熵算子,融合多尺度局部对比度构建高信杂比特征图,以对抗残余的局部熵散与赝像干扰。最后,利用自适应阈值分割完成小目标与背景的精确分离。实验表明,在干扰环境下本方法的边缘保持指数接近或高于1,杂波抑制因子、信杂比增益和背景抑制因子显著提升,且区域不均匀度始终低于0.2,验证了该方法在小目标精准检测方面的鲁棒性。

       

      Abstract: When detecting small targets in LiDAR imaging in interference environments, the accuracy of small target detection results is low due to the gray level collapse and edge contour inundation caused by complex background radiation. Therefore, this study proposes an accurate detection method for small targets based on the dual layer enhancement approach. After capturing the original image, guided filtering is used to decompose the image into a base layer and a detail layer. The basic layer compresses the dynamic range through adaptive guided filtering histogram mapping to correct gray level collapse, while the detail layer uses saturation processing to suppress shot noise and restores submerged edge contours through adaptive gain control. Two layers are fused with fixed coefficient weighting to achieve detail enhancement. Then, the local entropy operator is improved through spatial distance weighting, and multi-scale local contrast is fused to construct a high signal-to-noise ratio feature map to counteract residual local entropy scattering and artifact interference. Finally, using adaptive threshold segmentation to achieve precise separation of small targets from the background. The experiment shows that under interference environment, the edge preservation index of this method is close to or higher than 1, and the clutter suppression factor, signal-to-noise ratio gain, and background suppression factor are significantly improved. Moreover, the regional non-uniformity is always below 0.2, which verifies the robustness of this method in accurate detection of small targets.
       

       

    /

    返回文章
    返回