Pansharpening Quality Assessment using Modulation Transfer Function Filters

Quality assessment of pansharpening methods is not a trivial task. The generally used indexes i.e., Q4, SAM and ERGAS require a reference image at the same resolution as the fused image. Since, this reference image is not available the quality of pansharpening algorithms is tested at degraded resolution. However, this does not provide the means to assess the quality of fused images at the desired high resolution. In this paper we propose a method to assess the fusion quality at high resolution by making use of modulation transfer function filters in the frame works of Wald's spectral consistency protocol and Zhou's spatial quality protocol. The results are compared with the recently proposed QNR quality index which also does not require a reference high resolution multispectral image, Zhou's protocol, Q4, ERGAS and SAM.