Patent ID: 7274492

Claim:
In a printing system, a method for minimizing artifacts produced at a border produced by printing with a primary halftone screen on one side of the border and printing with a secondary halftone screen at the other side of the border, comprising: providing a document to be printed; rendering the document into a full color bit raster; converting the rendered document to the printing system's color space; halftoning the converted document, wherein halftoning include calibration of primary and secondary halftone screens for each color separation, comprising: generating a first tone reproduction curve (TRC) associated with the primary halftone screen using input values from a selected color separation and primary halftone screen output characteristics, wherein each primary halftone screen output characteristic is a function of measured luminance (delta-e from paper); generating a second TRC associated with the secondary halftone screen using the first TRC, the primary halftone screen characteristics and secondary halftone screen output characteristics, wherein each secondary halftone screen output characteristic is a function of measured luminance (delta-e from paper), comprising: for each input value in the selected color separation, determining a first TRC output value and an effective primary halftone screen output characteristic value associated with the first TRC output value; and determining a secondary screen characteristic value having the same luminance at the effective primary halftone screen output characteristic value associated with the first TRC output value; determining a second TRC output value based upon the secondary screen characteristic value having the same luminance as the effective primary halftone screen output characteristic value and the input value; and printing the halftoned document.