Multi-level receptive field feature reuse for multi-focus image fusion

Multi-focus image fusion, which is the fusion of two or more images focused on different targets into one clear image, is a worthwhile problem in digital image processing. Traditional methods are usually based on frequency domain or space domain, but they cannot guarantee the accurate measurement of all the image details of the activity level, and also cannot perfect the selection of image fusion rules. Therefore, the deep learning method with strong feature representation ability is called the mainstream of multi-focus image fusion. However, until now, most of the deep learning frameworks have not balanced the relationship between the two input features, the shallow features and the feature fusion. In order to improve the defects of previous work, we propose an end-to-end deep network, which includes an encoder and a decoder. Encoder is a pseudo-Siamese network. It extracts the same and different feature sets by using the features of double encoder, then reuses the shallow features and finally forms the coding. In decoder, the coding will be analyzed and dimensionally reduced enough to generate high-quality fusion image. We carried out extensive experiments. The results show that our network structure is better. Compared with various image fusion methods based on deep learning and traditional multi-focus image fusion methods in recent years, our method is slightly better than theirs in both objective metric contrast and subjective visual contrast.