I just don't understand how they could possibly be five times larger. There are 4x as many pixels, so by straight pixel count it could be 4x larger. However, c

I just don't understand how they could possibly be five times larger. There are 4x as many pixels, so by straight pixel count it could be 4x larger. However, current PNG compressors are really good at optimizing flat color areas, gradients, and lines. It seems to me like most images would get only a relatively small increase in size due to this upsizing (1.5x-2x).