Architecture of the proposed ADAPTIVE-NET. The network has three units: the projection domain unit (PDU), self-developed domain transformation unit (DTU), and the image domain unit (IDU). The first unit contains three layers, n64k(1,3) indicates 64 filters of kernel size 1×3, and the symbol ○C denotes concatenation of the feature maps. The network inside the IDU is the same as that of RED-CNN.