Method for compensating for color variations across a printed page using multiple color profiles
A method for compensating for color variations introduced by printer hardware limitations and other factors is described. First, the extent of color variation throughout a printed page is determined. Based on this determination, each page is partitioned into a plurality of image areas. A color profile is generated for each image area. The partition and the multiple color profiles are stored in the printer. In an actual printing process, the page of image to be printed is divided into a plurality of image areas based on the paper size and the stored partition, and the respective stored color profiles for the image areas are retrieved and used to process the digital image for printing.
1. A method for reducing color variation across a page of image to be printed by a printer, comprising:
(a) printing a full size page of engine test chart using the printer, the full size page corresponding to a full printable area of the printer;
(b) measuring the printed engine test chart to obtain color values at different locations of the full size page;
(c) calculating an amount of color variation for a plurality of locations on the full printable area of the printer, and based on the calculated amount of color variations and independent of any image to be printed, determining a page partition for dividing the full printable area of the printer into two or more image areas;
(d) generating a color profile for each image area; and
(e) storing the page partition and the color profile for each image area in the printer.
2. The method of claim 1 , wherein step (d) includes:
(d1) printing a page of full size color measurement chart, the color measurement chart including a full color measurement chart in each image area;
(d2) measuring the printed full size color measurement chart to obtain color measurement values; and
(d3) based on the color measurement values and a set of target values, generating a color profile for each image area.
3. The method of claim 1 , wherein step (c) includes calculating an amount of color variation for a plurality of locations on the full printable area of the printer.
4. A method for printing a page of image using a printer, comprising:
(a) receiving a page of digital image data to be printed;
(b) retrieving page partition information stored in the printer, the page partition information specifying a partition of a full size page corresponding to a full printable area of the printer into two or more image areas;
(c) detecting a paper size of the page of image to be printed;
(d) dividing the page of image to be printed into two or more image areas based on the detected paper size and the retrieved page partition information, by comparing the detected paper size with the full printable area of the printer to determine which image areas of the full printable area are covered by the detected paper size wherein the retrieved page partition information has been determined based on an amount of color variation for a plurality of locations on the full printable area of the printer;
(e) retrieving color profiles associated with the image areas;
(f) processing the digital image data, wherein the digital image data in each image area is processed using the color profile associated with that image area; and
(g) printing the processed image data.
5. A printer, comprising:
a print engine; and
a controller for processing digital image data to be printed and controlling the print engine, the controller including a processor and a memory;
wherein the memory stores page partition information which specifies a partition of a full size page into two or more image areas, and
wherein the controller is programmed to control the print engine to carry out a printing process which includes:
(a) receiving a page of digital image data to be printed;
(b) retrieving page partition information stored in the printer, the page partition information specifying a partition of a full size page corresponding to a full printable area of the printer into two or more image areas;
(c) detecting a paper size of the page of image to be printed;
(d) dividing the page of image to be printed into two or more image areas based on the detected paper size and the retrieved page partition information, by comparing the detected paper size with the full printable area of the printer to determine which image areas of the full printable area are covered by the detected paper size wherein the retrieved page partition information has been determined based on an amount of color variation for a plurality of locations on the full printable area of the printer;
(e) retrieving color profiles associated with the image areas;
(f) processing the digital image data, wherein the digital image data in each image area is processed using the color profile associated with that image area; and
(g) printing the processed image data.