Table 1 Total variance (TV) loss for different layers of CNN features.

From: Low-light image enhancement via adaptive frequency decomposition network

Features

T1 layer

T2 layer

T3 layer

T4 layer

U-Net

0.3913

0.2238

0.2355

0.1493

U-Net with AFD module

0.3946

0.4526

0.0665

0.0863