Multispectral and Panchromatic Data Fusion Assessment Without Reference

TLDR

Wang and Bovik’s image quality index (QI) provides a statistical similarity measurement between two monochrome images. This paper introduces a novel approach for evaluating the quality of pansharpened multispectral imagery without reference originals. The method computes Wang–Bovik QI values between MS bands and between each MS band and the PAN image before and after fusion, using unchanged QI values as measures of spectral and spatial distortion. Experimental results on Ikonos and simulated Pleiades data show the approach yields consistent, trend‑aligned results with spatially degraded data analysis, and it works without reference originals, making it usable in all practical cases.

Abstract

This paper introduces a novel approach for evaluating the quality of pansharpened multispectral (MS) imagery without resorting to reference originals. Hence, evaluations are feasible at the highest spatial resolution of the panchromatic (PAN) sensor. Wang and Bovik’s image quality index (QI) provides a statistical similarity measurement between two monochrome images. The QI values between any couple of MS bands are calculated before and after fusion and used to define a measurement of spectral distortion. Analogously, QI values between each MS band and the PAN image are calculated before and after fusion to yield a measurement of spatial distortion. The rationale is that such QI values should be unchanged after fusion, i.e., when the spectral information is translated from the coarse scale of the MS data to the fine scale of the PAN image. Experimental results, carried out on very high-resolution Ikonos data and simulated Pleiades data, demonstrate that the results provided by the proposed approach are consistent and in trend with analysis performed on spatially degraded data. However, the proposed method requires no reference originals and is therefore usable in all practical cases.