[robski]

Just in case a few of you were wondering what beat patterns are about I thought I would illustrate the effect.

I made an image with alternate black and white 10 pixel wide bars. I then scaled the image by 5.2% using nearest neighbour method ( upper half of attachment) and a method that looks at it's surrounding pixels and dithers (lower half of attachment). If you look in the upper half you will notice that every so often one of the white or black bars is slightly wider. From a distance the eye will pick this up as an interference pattern. In the lower half the dithering has reduced this effect.