Patent ID: 7310168

Claim:
A method for generating a spot for use in halftoning, comprising: defining a spot function that combines two functions selected to provide asymmetrically changing of the shape of a spot for use in a halftone cell; scaling the spot function according to grayscale levels using a parameterized spot radius scaling function that varies according to a value of a first and second spot function ordinate and an asymmetric shape changing scaling function based on a gray level for the spot, and printing using the scaled spot function; wherein the spot function is described by: f ⁢ ( x , y ) = 1 2 ⁢ ( cos ⁢ ( π ⁢ ⁢ x / p x ) + 1 S ⁢ ( p , r ) ⁢ cos ⁢ ⁢ ( π ⁢ ⁢ y / p y ) ) where x and y are the first and second spot function ordinates, p x scales ordinate x, p y scales ordinate y, p is a spot shape parameter for controlling the shape of the spot, S(p,r) is a scaling function, and r is the radius of the spot.