Improved Brovey transform by low-pass filter
用低通滤波器改进Brovey融合法*

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.