Abstract In image fusion approaches, feature extraction and processing are key tasks, and the fusion performance is directly affected by the different features and processing methods undertaken. However, most of deep learning-based methods use deep features directly without them. This leads to the fusion performance degradation in some cases. To solve these drawbacks, in our paper, a deep features and zero-phase component analysis (ZCA) based novel fusion framework is proposed. Firstly, the residual network (ResNet) is used to extract deep features from source images. Then ZCA and l 1 -norm are utilized to normalize the deep features and obtain initial weight maps. The final weight maps are obtained by employing a soft-max operation in association with the initial weight maps. Finally, the fused image is reconstructed using a weighted-averaging strategy. Compared with the existing fusion methods, experimental results demonstrate that the proposed framework achieves better performance in both objective assessment and visual quality. The code of our fusion algorithm is available at https: github.com hli1221 imagefusion_resnet50 .
@cite_26: AbstractWhitening, or sphering, is a common preprocessing step in statistical analysis to transform random variables to orthogonality. However, due to rotational freedom there are infinitely many possible whitening procedures. Consequently, there is a diverse range of sphering methods in use, for example based on principal component analysis (PCA), Cholesky matrix decomposition and zero-phase component analysis (ZCA), among others. Here we provide an overview of the underlying theory and discuss five natural whitening procedures. Subsequently, we demonstrate that investigating the cross-covariance and the cross-correlation matrix between sphered and original variables allows to break the rotational invariance and to identify optimal whitening transformations. As a result we recommend two particular approaches: ZCA-cor whitening to produce sphered variables that are maximally similar to the original variables, and PCA-cor whitening to obtain sphered variables that maximally compress the original variables.
. In @cite_26 , analyzed the whitening and decorrelation by ZCA operation. ZCA opeartion is used to project a random vector into a irrelevant sub-space which is also named whitening. In image processing field, ZCA is a very useful tool to process the features which can obtain useful features to improve algorithm performance. We will introduce ZCA operation briefly.