用低通滤波器改进Brovey融合法

Improved Brovey transform by low-pass filter

针对遥感图像融合Brovey变换法存在颜色失真的现象,提出了一种低通比值融合法。该融合法首先对高几何分辨率的全色波段进行低通滤波,然后将低分辨率多光谱图像与全色波段图像相乘,再除以滤波后的全色波段图像,便得到融合图像。从辐照的角度证明了该低通比值融合法具备理论基础,并从目视评价、定量分析、分类精度证实了该低通比值融合法优于Brovey变换法。该低通比值融合法能较好地保全低分辨率多光谱图像颜色的融合方法。

The conventional fusion method,such as Brovey transform,brought color distortion in proceeding image fusion.This paper analyzed its reason,and then proposed an improved algorithm,named panchromatic image low-pass filter based ratio fusion（Low-pass RF）.It firstly filtered the panchromatic band image through the low-pass filter,to generate a new image,PANlow image.Then Divided the PANlow image by the panchromatic image.Finally,it multiplied each quotient of the panchromatic image by PANlow image,to produce the resulting image.It also discussed its theory mechanism at terms of radiance.The results of visual interpretation and quantitative analysis to gray variance index show that the Low-pass RF transform have a capability of retaining color from multi-spectral image.Classification accuracy of the fused image by Low-pass RF transform is higher than the Brovey image.Therefore,Low-pass RF transform is more capable in retaining color than Brovey transform while the time of the panchromatic data differs from that of the multi-spectral data.