Training, testing, and validation sets for ML. Panels a–b: comparison of close-ups of the unprocessed AIA, PSF-bicubic-upscaled AIA, Ml-upscaled AIA, and Hi-C images. The images in panels a and b are taken from the testing set and validation set, respectively. Panel c: slice plots exhibiting intensities along the line indicated in panel b. Panel d: Hi-C image with its full field of view (FOV), in which the lower and upper blanked regions are taken as the validation set and testing set, respectively, and all of the left region is used as the training set. Panels e–f: time history of the value of MAE (e) and SSIM (f) between the model outputs and the Hi-C images in each dataset.