Table 3. Results based on LR-HR stage residual blocks. To calculate the multi-adds, we assume that the HR image is 720P and the upscaling factor ×4.

Dataset	Scale\LR-HR	18 - 2 PSNR/SSIM	8 - 2 PSNR/SSIM	VDSR [4] PSNR/SSIM
Set 5	× 2	37.57/0.9588	37.52/0.9585	37.53/0.9587
	× 3	33.90/0.9229	33.85/0.9226	33.66/0.9213
	× 4	31.53/0.8859	31.48/0.8854	31.35/0.8838
	× 2	33.01/0.9139	33.01/0.9137	33.03/0.9124
Set 14	× 3	29.87/0.8367	29.86/0.8364	29.77/0.8314
	× 4	28.26/0.7787	28.26/0.7782	28.01/0.7674
	× 2	31.91/0.8959	31.89/0.8954	31.90/0.8960
B100	× 3	28.85/0.7985	28.84/0.7981	28.82/0.7976
	× 4	28.34/0.7266	27.33/0.7262	27.29/0.7251
Urban 100	× 2	30.77/0.9146	30.73/0.9138	30.76/0.9140
	× 3	27.14/0.8289	27.14/0.8286	27.14/0.8279
	× 4	25.25/0.7554	25.26/0.7553	25.18/0.7524
Average		30.53/0.8514	30.43/0.8510	30.37/0.8490
Parameters		665K	296K	665K
Multi-adds		71.1G	49.9G	612.6G