Self-calibration of network copier system
AssigneeSeiko Epson Corporation
InventorsTsung-Nan Lin, Joseph Shu
Life of this patent
Estimating the term…
Abstract
A technique for calibrating non-reference printers to a reference printer in a network system by determining a set of four 1-D look-up tables for each non-reference printer. Each set of four 1-D look-up tables is constructed from a corresponding set of transfer functions, where each transfer function in a given set is a composite of a 1-D characteristic function for a particular primary color of the reference printer and a 1-D inverse characteristic function for that particular primary color of the corresponding non-reference printer. The characteristic functions are determined by performing a specific color space transformation analysis on each non-reference printer and on the reference printer.
Claims25
A method for calibrating at least one non-reference imaging device to a reference imaging device, comprising the steps of:
- determining a set of 1-D characteristic functions for each non-reference imaging device, each set relating a plurality of primary colors of that non-reference imaging device with a plurality of color elements of an input device;
- determining a set of 1-D characteristic functions for the reference imaging device relating a plurality of primary colors of the reference imaging device with a plurality of color elements of the input device;
- determining a set of 1-D transfer functions in the form of a set of 1-D look-up tables for each non-reference imaging device based on the determined set of 1-D characteristic functions for the reference imaging device and the determined set of 1-D characteristic functions for that non-reference imaging device;
- and
- applying each set of 1-D look-up tables to the corresponding non-reference imaging device to calibrate that non-reference imaging device to the reference imaging device.
An network imaging system comprising:
- an input device for generating an input device representation of an image;
- a reference imaging device capable of producing an output image in response to an input image;
- and
- a plurality of non-reference imaging devices each capable of producing an output image in response to the input image, each non-reference imaging device having a set of 1-D transfer functions in the form of look-up tables, wherein each 1-D transfer function in a given set is a composite function of a first type of 1-D characteristic function which relates a primary color of the reference imaging device with at least one color element of the input device and a second type of 1-D characteristic function which relates a primary color of that non-reference imaging device with at least one color element of the input device.
A system having means for performing a method of calibrating at least one non-reference imaging device to a reference imaging device, said means for performing comprising at least one of a program of system executable instructions and hardware, said method comprising the steps of:
- determining a set of 1-D characteristic functions for each non-reference imaging device, each set relating a plurality of primary color of that non-reference imaging device with a plurality of color elements of an input device;
- determining a set of 1-D characteristic functions for the reference imaging device, each characteristic function relating a plurality of primary colors of the reference imaging device with the plurality of color elements of the input device;
- determining a set of 1-D transfer functions in the form of a set of 1-D look-up tables for each non-reference imaging device based on the determined set of 1-D characteristic functions for the reference imaging device and the determined set of 1-D characteristic functions for that non-reference imaging device;
- and
- applying each set of 1-D look-up tables to the corresponding non-reference imaging device to calibrate that non-reference imaging device to the reference imaging device.
A processor-readable medium having a program of instructions embodied therein for causing a processor to calibrate at least one non-reference imaging device to a reference imaging device, said program including instructions for:
- determining a set of 1-D characteristic functions for each non-reference imaging device, each set relating a plurality of primary colors of that non-reference imaging device with a plurality of color elements of an input device;
- determining a set of 1-D characteristic functions for the reference imaging device relating a plurality of primary colors of the reference imaging device with a plurality of color elements of the input device;
- determining a set of 1-D transfer functions in the form of a set of 1-D look-up tables for each non-reference imaging device based on the determined set of 1-D characteristic functions for the reference imaging device and the determined set of 1-D characteristic functions for that non-reference imaging device;
- and
- applying each set of 1-D look-up tables to the corresponding non-reference imaging device to calibrate that non-reference imaging device to the reference imaging device.
A carrier wave encoded to transmit a program of instructions executable by a machine to perform a method of calibrating at least one non-reference imaging device to a reference imaging device, said program including instructions for:
- determining a set of 1-D characteristic functions for each non-reference imaging device, each set relating a plurality of primary colors of that non-reference imaging device with a plurality of color elements of an input device;
- determining a set of 1-D characteristic functions for the reference imaging device relating a plurality of primary colors of the reference imaging device with a plurality of color elements of the input device;
- determining a set of 1-D transfer functions in the form of a set of 1-D look-up tables for each non-reference imaging device based on the determined set of 1-D characteristic functions for the reference imaging device and the determined set of 1D characteristic functions for that non-reference imaging device;
- and
- applying each set of 1-D look-up tables to the corresponding non-reference imaging device to calibrate that non-reference imaging device to the reference imaging device.
Dependencies are inferred from the claim text.