Hi I have an Idea

[Andrés]

Every ship size needs a 128x128 "portrait" and a 36x36 "mini".
You will allways lose some details when reducing to those sizes, but if resampled nicely they should look ok anyway.
Another important detail is that minis should show relative sizes between the ships, so the largest ones should use all 36 pixels of its mini while the smallest much less.