Down-up sampling iterative process used to allow the simulation of very large galaxies. Top left: Original high-resolution sample. Top right: Downsampled version. Bottom left: Upscaled version from bi-quadratic interpolation. Bottom right: Residual image between original and upscaled version. In this example, we show a smaller sample of 120 pixels in width for visualisation purposes, but the galaxy stamps that require to be resampled with this process are typically above one thousand pixels wide. Shown is the result of downsampling by a factor of 4; the bi-quadratic 2D interpolation results in a very similar profile in comparison to the original and it minimizes the residual compared to other interpolation methods.