关键词: 影像融合框架, Worldview 3影像, 短波红外, 全色, 高通滤波融合法, GS融合法

Abstract:

Worldview 3 is one of the most advanced high-resolution optical satellites. The large spatial resolution difference and inconsistent spectral ranges between panchromatic band and Short-Wave Infrared bands（SWIR） of Worldview 3 data sets bring great challenge to the fusion. Therefore, a two-step image fusion framework is proposed to solve the problem of blocky effects and limited spatial resolution enhancement effectiveness. The framework reduces the spatial resolution of panchromatic band to achieve the first fusion with SWIR bands. The results of the initial fusion are then fused with the original resolution panchromatic band in the second step. By choosing and combining 6 typical pixel-level fusion methods in pairs, 36 fusion schemes are formed to verify the usability of the framework. The Worldview 3 data set, consisting of typical land types such as vegetation, buildings and water, is selected for the experiment, and five quantitative evaluation indexes are used for the evaluation. The experimental results show that the spatial resolution of SWIR bands is enhanced by the progressive spatial detail injection process under the proposed framework, which avoids the block effect caused by one-step fusion methods. Under the framework, when HPF（High Pass Filter） fusion method is adopted in the first fusion step, and GS（Gram-Schmidt） fusion method is adopted in the second fusion step, the most spatial information is injected and the best fusion result quality is achieved. The proposed fusion framework can not only avoid block effect, but also effectively enhance the spatial resolution of SWIR band. The framework also can be transferred to the fusion of panchromatic and short-wave infrared bands of other satellites.

Key words: image fusion framework, Worldview 3 images, short-wave infrared, panchromatic, High Pass Filter（HPF） fusion, Gram-Schmidt（GS） fusion