Reduction of intercolor bleeding in liquid ink printing

A method of processing color image data for printing on an inkjet printer to reduce intercolor bleeding in an image recorded on a receiving medium, comprising:

• receiving a target pixel comprising multiple separation pixels, each separation being associated with a separate color plane and having at least three states, a first state corresponding to depositing no ink drops, a second state corresponding to depositing one ink drop, and a third state corresponding to depositing more than one ink drop;
• determining if the target pixel is within a black border region near a black/color interface, and if so, replacing the target pixel with a black border output pixel derived from a black pixel modification pattern, the black pixel modification pattern identifying an arrangement of separation pixels to deposit approximately one drop for each pixel location in the black pixel modification pattern;
• and
• determining if the target pixel is within a color border region near a black/color interface, and if so, replacing the target pixel with a color border pixel derived from a color pixel modification pattern the color pixel modification pattern identifying an arrangement of separation pixels for each non-black color plane that deposits approximately one drop for each pixel location.

A device for processing color image data including multiple color planes each of which comprises an array of separation pixels, each separation pixel having at least three states, a first state corresponding to depositing no ink drops, a second state corresponding to depositing one ink drop, and a third state corresponding to depositing more than one ink drop to reduce intercolor bleeding in an image recorded on a receiving medium, the device comprising:

• a statistics collection filter connected to receive a target pixel and a set of surrounding pixels, the statistics collection filter generating a statistics signal;
• a pixel identification circuit connected to receive the statistics signal, the identification circuit generating a pixel identification signal indicating whether the target pixel is within a black border or a color border;
• and
• a pixel modification circuit connected to receive the pixel identification signal, the modification circuit modifying the target pixel according to a black pixel modification pattern when the target pixel is within a black border and modifying the target pixel according to a color pixel modification pattern when the target pixel is within a color border, wherein the black pixel modification pattern identifies an arrangement of separation pixels to deposit approximately one drop for each pixel location in the black pixel modification pattern and the color pixel modification pattern identifies an arrangement of separation pixels for each non-black color plane that deposits approximately one drop for each pixel location.

A method of processing color image data for printing on an inkjet printer to reduce intercolor bleeding in an image recorded on a receiving medium, comprising:

• receiving color image data comprising multiple color planes that combine to form an array of composite pixels, the multiple color planes including at least one black plane and at least one non-black plane, wherein each color plane comprises an array of separation pixels, each separation pixel having at least three states, a first state corresponding to depositing a first volume of ink, and a third state corresponding to depositing a second volume of ink, the second volume of ink being greater than the first volume of ink;
• identifying an interface between a black area and a color area;
• modifying the color image data corresponding to an M-pixel wide color border in the color area to reduce in a non-black plane the number of separation pixels having a third state;
• and
• modifying the color image data corresponding to an N-pixel wide black border in the black area to reduce in a black plane the number of separation pixels having a third state.