Method for resolution error detection in print device using iterative transform
AssigneeXerox Corporation
InventorsEthan Weston Hughes, Stuart A. Schweid, John T. Newell
Life of this patent
Estimating the term…
Abstract
Methods of identifying and measuring resolution error in a print device are disclosed. The methods include processing a scan of a document on which targets are printed at known reference locations. The system identifies and performs a 1D Hough transform process on each of the targets. In the process, the system measures differences between an identified location for each target and an expected location for each target. The system then uses the difference to measure the document's image resolution and estimate resolution error, if any, in the document.
Claims20
A method for identifying resolution error in a print device, the method comprising, by a processing device:
- processing a scan of a document comprising an image with a plurality of targets printed at known reference locations on a substrate;
- locating the targets in the image;
- for each of the targets, performing a 1D Hough transform process that comprises:
- performing a plurality of 1D Hough transformations to generate a plurality of lines,
- identifying a location where the plurality of lines intersect,
- measuring a difference between the identified location and a reference location, wherein the reference location is an expected location for the target,
- using the difference to measure a resolution of the image, and
- estimating an error value between the measured resolution and an expected resolution of the image;
- and
- using the estimated error value to estimate a resolution error of a print device that printed the document.
A computer program product comprising a non-transitory memory device containing programming instructions that are configured to, when executed by a processor, cause the processor to:
- process a scan of a document comprising an image with a plurality of targets printed at known reference locations on a substrate;
- locate the targets in the image;
- for each of the targets, perform a 1D Hough transform process that comprises:
- performing a plurality of 1D Hough transformations to generate a plurality of lines,
- identifying a location where the plurality of lines intersect,
- measuring a difference between the identified location and a reference location, wherein the reference location is an expected location for the target,
- using the difference to measure a resolution of the image, and
- estimating an error value between the measured resolution and an expected resolution of the image;
- and
- use the estimated error value to estimate a resolution error of a print device that printed the document.
A system comprising:
- a print device comprising one or more print heads;
- and
- a controller comprising a processor and a memory device, wherein the controller is included in or communicatively connected with the print device,
- wherein the memory contains programming instructions that are configured to, when executed by the processor, cause the processor to:
- process a scan of a document comprising an image with a plurality of targets printed by the print device at known reference locations on a substrate;
- locate the targets in the image;
- for each of the targets, perform a 1D Hough transform process that comprises:
- performing a plurality of 1D Hough transformations to generate a plurality of lines,
- identifying a location where the plurality of lines intersect,
- measuring a difference between the identified location and a reference location, wherein the reference location is an expected location for the target,
- using the difference to measure a resolution of the image, and
- estimating an error value between the measured resolution and an expected resolution of the image;
- and
- use the estimated error value to estimate a resolution error of the print device.
Dependencies are inferred from the claim text.