Table 6. Ablation study on the proposed hybrid loss function.

Loss	$\times$ 2			$\times$ 4
	PSNR $\uparrow$	SSIM $\uparrow$	RMSE $\downarrow$	PSNR $\uparrow$	SSIM $\uparrow$	RMSE $\downarrow$
MAE	32.1716	0.8840	6.3053	31.4376	0.8704	6.8628
MAE+FFT	32.1815	0.8841	6.2997	31.4832	0.8712	6.8254