Patent ID: 7239426

Claim:
An image conversion apparatus for converting an input image having a process color component and a spot color component, which is represented by density data for colors, into a halftone dot image represented by halftone dot data for colors of process colors, said image conversion apparatus comprises: first halftone dot providing means for providing the process color component constituting the input image in form of a halftone dot expression using a predetermined halftone dot sort; spot color separating means for separating the spot color component constituting the input image into the process colors; second halftone dot providing means for providing the spot color component separated into the process colors by said spot color separating means in form of a halftone dot expression using a halftone dot sort different from the halftone dot sort used in said first halftone dot providing means; and halftone dot synthesizing means for synthesizing the process color component provided in form of a halftone dot expression obtained in said first halftone dot providing means with the spot color component separated into the process colors and provided in form of a halftone dot expression obtained in said second halftone dot providing means for each color of the process colors.