A feature-based metric for the quantitative evaluation of pixel-level image fusion

Pixel-level image fusion has been investigated in various applications and a number of algorithms have been developed and proposed. However, few authors have addressed the problem of how to assess the performance of those algorithms and evaluate the resulting fused images objectively and quantitatively. In this study, two new fusion quality indexes are proposed and implemented through using the phase congruency measurement of the input images. Therefore, the feature-based measurements can provide a blind evaluation of the image fusion result, i.e. no reference image is needed. These metrics take the advantage of the phase congruency measurement which provides a dimensionless contrast- and brightness-invariant representation of image features. The fusion quality indexes are compared with recently developed blind evaluation metrics. The validity of the new metrics are identified by the test on the fusion results achieved by a number of multiresolution pixel-level fusion algorithms.