“…In image processing, wavelet transform is often used as a tool for content information analysis [34]. With the development of DNNs, wavelet transform has several attempts to combine the classical signal processing and deep learning methods, such as image denoising [20,31,47], super resolution [16,30], classification [7,25,29], segmentation [24], facial aging [32], style transfer [50], remote sensing image processing [9], etc. It is often used as the tool of data preprocessing, post-processing, feature extraction, and sampling operators in DNNs [16,32,39,48,30,23].…”