Example of a simulation image (upper left) or cube slice of thickness ≈0.4 Mpc (lower left), histogram of the pixel values before and after log-like transformation (middle), and pixel value transformation function (right) for the images (top) and cubes (bottom). In the middle column, gray represents the pixel value histogram in linear scale, and blue shows the pixel value histogram after log-like transformation (Eq. (1) at the top and Eq. (2) at the bottom) of the images. For both cases, the GAN has been trained using the log-transformed sets of images.