Specify sprite type
You can specify the type of the image in the sprite: Illustration or Photo.
1. Select the sprite.
2. Right-click and choose Properties.
3. Click on the Image tab. You can read in this box, the filename and its location, its specifications (Image format, Size, colors).
4. In the Type of Image group:
If you specify this image as an Illustration (generally objects with transparency) it will automatically be compressed and converted using the PNG format during compilation. This compression is lower than JPEG but do not alter the image and preserve transparency.
If you specify this image as a Photo (generally pictures without transparency) it will automatically be compressed and converted using the JPEG format during compilation. This compression is higher than PNG but may alter the image and not preserve transparency.