Wavelet noise
Appearance
Wavelet noise is an alternative to Perlin noise which reduces the problems of aliasing and detail loss that are encountered when Perlin noise is summed into a fractal.
Algorithm detail
[edit]The basic algorithm for 2-dimensional wavelet noise is as follows:
- Create an image, , filled with uniform white noise.
- Downsample to half-size to create , then upsample it back up to full size to create .
- Subtract from to create the end result, .
This results in an image that contains all the information that cannot be represented at half-scale. From here, can be used similarly to Perlin noise to create fractal patterns.
External links
[edit]- Wavelet Noise Paper at pixar.com.