As we all know rotating/scaling sprites with Photoshop and Gimp screw some pixels giving a mostly bad looking results so here is a tool that does those two jobs way better.
A short explication by O"llucionista.
This info is so useful that needs to be shared with everyone. Thanks to nedflandeurse for finding this gem.
There are some times that we want to scale or rotate sprites to make new ones, and most graphic programs will just ruin the sprites - by blurring then or by messing up the pixels.
The solution is a free program called RotSprite, which have unbelievable results.
What it is?
How it works?
The program interface is very simple. You choose which image you will use (accepts many formats), the output name (just outputs BMP) then you will see this:
First box: you will enter the angle of the rotation (if you don't want rotation, just put 0). Try to use integer numbers, and remember graphic programs works better in 15º subdivision, so any multiple (15º, 30º, 45º and so on). Remember that is in counter-clockwise, so if you wanna rotate 45 CLOCKWISE, you need to enter 315º or use a negative value (-45º).
Second box: Its the scale value. If you doesn't wants a scale, leave it alone (do not use 0). Again, the same 15 multipies will work here, but multiples of 10 will work too. 1.000000 means 1 (normal size), 2.000000 doubles it, 0.500000 half size and so on.
Scale down works better than scale up. But the result is better than any other tool.
Third box you can enter how much frames do you want, and the final rotation and it will made as much frames as needed.
Scale (zoomed for better view)