Patent ID: 6081343
Filing Date: 2000-06-27
Classification: H04N

Abstract:
An image data conversion method for a digital printer, for converting input image data, corresponding to a full-color original image on a particular recording medium, to converted image data for production of a corresponding full-color image on a recording material by said digital printer, the method comprising the steps of:providing predetermined reference gradation characteristics for a reference recording medium type;obtaining common gradation characteristics for a particular recording medium type pertaining to said particular recording medium, said particular recording medium type being different from said reference recording medium type;determining conversion conditions based on said common gradation characteristics and said reference gradation characteristics;converting said input image data to said converted image data using said conversion conditions;determining a high-density reference value and a low-density reference value of said original from said input image data;obtaining high-density reference balance values and low-density reference balance values from said common gradation characteristics in correspondence with said high density and low density reference values, respectively;storing predetermined recording data reference values to which said reference balance values are to correspond;detecting, for each of three colors:a first coordinate point defined by said high-density reference balance value of said each color and a corresponding one of said recording data reference values, anda second coordinate point defined by said low-density reference balance value of said each color and a corresponding one of said recording data reference values;connecting said first coordinate point and said second coordinate point to produce a conversion table function for each said color relating said image data to said recording data; andusing said conversion table function as said conversion conditions.