Figure2

Figure 2. Schematic diagram of the structure of a multi-scale residual block. 3 × 3: filter size. Conv: Convolutional layer; Concat: establish dense connections between the front and back layers; BN: batch normalization. ($$ xi $$ expresses the N subsets into which it is divided after the first 1 × 1 convolution and $$ yi $$ expresses the N set of features obtained after $$ xi $$ undergoes a 3 × 3 convolution operation.)