Why do some background transparent images have a “Halo”?
Importing 8 or 16 bit graphics with a white background will sometimes appear to have a halo around them made up of white pixels. If you examine them closely you will see that these are actually off-white, anti-aliased pixels. There are 2 ways to remedy this. 1. Use 32 bit images with an alpha channel. The alpha channel contains transparency information (see below) and increases file size. 2. Remove the anti-aliased edge with a true white edge but this will give the edge a pixelated look. 3. Anti-alias the edge to the background colour of your stage. 4: Use a mask image in the cast with mask ink on the sprite. See the mask tutorial to see how to do this. Check out the DOUG article ‘Soft Masking Technique and Drop Shadow’. And here’s another technique for Anti-aliasing.
