1. A method for implementing digital halftoning of an image, the method comprising: for each pixel in the image: indexing a two-dimensional look up table using a position of the pixel; identifying a threshold value for the pixel from the two-dimensional look up table; creating an index that indexes a three-dimensional lookup table using the threshold value and the position of the pixel; and obtaining an output value for the pixel by indexing the three-dimensional look up table via the index; and producing a halftone representation of the image from output values for corresponding pixels.