摘要
在穿墙雷达成像技术中,建筑布局成像对确定墙后人体目标的空间相对位置以及多径虚假目标的提取有重要意义。目前的建筑布局成像一般采用多通道多视角图像融合方法,对此提出一种基于多尺度分析,即基于小波分解下的多通道多视角图像融合算法。该算法分为两个阶段,第一阶段涉及到单视角下的多通道图像融合,该阶段的融合目的主要是为增强图像细节信息和提高图像清晰度。因此对其小波分解后的图像高频分量采用平均梯度增强的加权融合算法,低频分量采用平均加权融合,后经小波反变换后形成多幅单视角图像;第二阶段涉及到多视角融合,该阶段的融合目的主要是为了增强图像的对比度,并且考虑到此阶段不同视角下图像经小波分解后的三个高频分量对比度各不相同,因此高频分量采用对比度增强的加权融合算法,低频分量仍采用平均加权融合,后将融合后的频率分量经小波反变换,便可得到一幅完整融合图像。仿真结果表明,提出的基于小波分解下的多通道多视角图像融合算法不论在图像视觉效果的改善和信噪比的提高等方面都有较大的作用。
For through-wall-radar imaging, the image of building layout is conducive to implementing target localization and multi-path suppression. The current access to the building image is obtained by multi-channel and multi-view image fusion. In this paper, an image fusion method based on multiscale geometric analysis, namely wavelet transform（WT） is proposed to form a panorama image of building layout. The method is divided into two stages. The first stage refers to the multi-channel image fusion. The purpose of this stage is to enhance image details and improve image definition. Hence the fusion method of high frequency of the sub-images after WT is based on average gradient improvement. For the low frequency sub-image, average coefficient is adopted, then several single view images is obtained through inverse wavelet transform. The second stage refers to the multi-view image fusion. The purpose of this stage is to enhance the contrast of image. Given that the image contrast of high frequency of multi-view sub-images differs from one another, the fusion method of high frequency of the sub-image is based on image contrast improvement. For the low frequency sub-image, average coefficient is adopted. Then, the final image is obtained through inverse wavelet transform by the low frequency image and the high frequency images. Simulation results show that the proposed algorithm can enhance the peak signal to noise ratio（PSNR）, leading to noticeable improvement in visual quality.
出处
《雷达科学与技术》
2014年第3期253-261,共9页
Radar Science and Technology
基金
国家自然科学基金(No.61178068)
四川青年基金人才培养计划(No.2011JQ0024)
关键词
穿墙雷达
建筑布局成像
多通道多视角图像融合
小波变换
through-wall-radar
image of building layout
multi-channel and multi-view image fusion
wavelet transform
