“…We used subjective and objective aspects to evaluate the image enhancement effects. In terms of the objective metrics, six evaluation metrics were applied, namely information entropy (H) [32], mean square error (MSE) [33], peak signal-to-noise ratio (PSNR) [34], gradient magnitude similarity deviation (GMSD) [35], mean absolute error (MAE) [36], and multi-scale structural similarity (MSSSIM) [37]. For the indicators of H, PSNR, and MSSSIM, larger values demonstrate a better enhancement of the image; for the other three metrics MSE, GMSD, and MAE, lower values demonstrate a better enhancement of the image.…”