FUBAR uses the statistical technique "Kriging" to rescale images with an global geometric pattern, called the variogram.

The image can be infinitely rescaled: the estimates ('o' on the left figure) are calculated from five neighbouring samples of the source image ('+' on the left figure). The image is 'noisy' because each pixel is a realization of the estimated value. In other words, each pixel is a random value with a mean and a variance from the local distribution. By changing the variogram (press 'v') or the variance multiplier, it is possible to control that variance.

Clicking the left mouse button zooms in on the image and right-click zooms the image back out. Press SPACEBAR to accept the current realization as the 'source image' -this will reduce noise at small scales.