Least squares based exposure modulation for banding compensation
AssigneeXerox Corporation
InventorsPalghat Ramesh, Peter Paul
Life of this patent
Estimating the term…
Abstract
A method, system, and computer program product for estimating exposure modulation in an image printing system is disclosed. The method includes determining a banding profile for an image printing system by a processor; determining an adjusted exposure modulation profile based on the banding profile using a least squares estimation by the processor; and printing an output based on the adjusted exposure profile.
Claims21
A method for estimating an exposure modulation in an image printing system comprising at least one marking engine, the at least one marking engine comprising a charging device for charging the image bearing surface, an exposing device for irradiating and discharging the image bearing surface to form a latent image, and a developer unit for developing toner to the image bearing surface, the method comprising:
- determining, using a processor, a banding profile for an image printing system at different area coverages of a Tone Reproduction Curve (TRC), wherein the procedure of determining the banding profile further comprises:
- obtaining image data across multiple measurement intervals for each area coverage by one or more sensors,
- combining the image data with timing information into a coherent signal, and analyzing the coherent signal for periodic and aperiodic components for each area coverage,
- wherein the periodic components represent the banding profile;
- determining, using the processor, an adjusted exposure modulation profile based on the determined banding profile using a least squares estimation;
- and
- printing an output based on the adjusted exposure modulation profile,
- wherein the adjusted exposure modulation profile is configured to provide an optimal banding correction across all the area coverages of the TRC.
A system for estimating an exposure modulation in an image printing system:
- a marking engine;
- a sensor configured to obtain image data across multiple measurement intervals;
- an exposing device;
- and
- a processor configured to:
- determine a banding profile for the image printing system at different area coverages of a Tone Reproduction Curve (TRC), wherein to determine the banding profile the processor is further configured to:
- obtain image data across multiple measurement intervals for each area coverage by one or more sensors,
- combine the image data with timing information into a coherent signal, and
- analyze the coherent signal for periodic and aperiodic components for each area coverage,
- wherein the periodic components represent the banding profile,
- determine an adjusted exposure modulation profile based on the determined banding profile using a least squares estimation,
- wherein the adjusted exposure modulation profile is configured to provide an optimal banding correction across all the area coverages of the TRC.
A non-transitory computer-readable storage medium comprising a computer program product encoded with computer executable instructions that when executed by a processor are configured, to implement a method for estimating an exposure modulation in an image printing system, said method comprising:
- determining a banding profile for an image printing system at different area coverages of a Tone Reproduction Curve (TRC), wherein the procedure of determining the banding profile further comprises:
- obtaining image data of images sensed across multiple measurement intervals for each area coverage by a sensor,
- combining the image data with timing information into a coherent signal, and
- analyzing the coherent signal for periodic and aperiodic components for each area coverage,
- wherein the periodic components represent the banding profile;
- and
- determining an adjusted exposure modulation profile based on the determined banding profile using a least squares estimation,
- wherein the adjusted exposure modulation profile is configured to provide an optimal banding correction across all the area coverages of the TRC.
Dependencies are inferred from the claim text.