A comparison study on fusion methods using evaluation indicators

Various fusion methods have been developed for improving data spatial resolution. The methods most encountered in the literature are the intensity-hue-saturation (IHS) transform, the Brovey transform, the principal components algorithm (PCA) fusion method, the Gram-Schmidt fusion method, the local mean matching method, the local mean and variance matching method, the least square fusion method, the discrete wavelet fusion method including Daubechies, Symlet, Coiflet, biorthogonal spline, reverse biorthogonal spline, and Meyer wavelets, the wavelet-PCA fusion method, and the crossbred IHS and wavelet fusion method. Using various evaluation indicators such as two-dimensional correlation, relative difference of means, relative variation, deviation index, entropy difference, peak signal-to-noise ratio index and universal image quality index, as well as photo-interpretation methods and techniques, results of the above fusion methods were compared and comments on the fusion methods and potential of evaluation indicators were made. Among data fusion methods and indicators the local mean and variance matching methods proved the most efficient and the peak signal-to-noise ratio indicator proved the most appropriate for the evaluation of data fusion results.