Image transformations based on defects

• US 10,457,066 B2
• Filed: 11/30/2015
• Issued: 10/29/2019
• Est. Priority Date: 11/30/2015
• Status: Expired due to Fees

• Current Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Original Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Inventors: Perdicaro, Frank E., Galmes, Jose
• Primary Examiner(s): Fidler, Shelby L
• Application Number:
  US15/760,314
• Publication Number:
  US 20180257392A1
• Time in Patent Office: 1,429 Days
• CPC Class Codes: B41J 2/2139 Compensation for malfunctioning nozzles creating dot place or dot size errors generating single droplets or particles on demand by pressure, e.g. electromechanical transducers B41J2/045
• CPC Class Codes: B41J 2/2142 Detection of malfunctioning nozzles generating single droplets or particles on demand by pressure, e.g. electromechanical transducers B41J2/045, B41J2/05; jet deflection sensors B41J2/125; for cleaning purposes B41J2/16579
• CPC Class Codes: B41J 2/2146 for line print heads
• CPC Class Codes: B41J 29/393 Devices for controlling or analysing the entire machine ; Controlling or analysing mechanical parameters involving printing of test patterns
• CPC Class Codes: G06T 3/02 Affine transformations for image registration G06T3/147; for image mosaicing G06T3/4038
• CPC Class Codes: G06T 3/60 Rotation of whole images or parts thereof
• CPC Class Codes: H04N 1/00037 Detecting, i.e. determining the occurrence of a predetermined state H04N1/00031 takes precedence
• CPC Class Codes: H04N 1/00045 using a reference pattern designed for the purpose, e.g. a test chart

Abstract

An example system includes a print engine to print a first image on a medium. The system also includes a controller communicatively coupled with the print engine. The controller is to detect a failure in the print engine that results in a defect in the first image. The controller also is to perform an affine transformation on a second image to produce a transformed second image. The controller is to instruct the print engine to print the transformed second image.

Claims

1. A system, comprising:

a print engine to print a plurality of images on a medium, wherein each one of the plurality of images is printed on a respective ribbon of a plurality of ribbons on the medium, wherein each one of the plurality of ribbons comprises an elongated strip on the medium to receive a respective image that is repeated end-to-end along the elongated strip; and

a controller communicatively coupled with the print engine, the controller to;

detect a failure that results in a defect in a first image of the plurality of images in the respective ribbon of the first image while the print engine is printing the plurality of images,

perform an affine transformation on a second image in the respective ribbon of the first image in response to the failure that is detected to produce a transformed second image, wherein the controller is to perform the affine transformation of the second image by performing a 180-degree rotation of the second image that is repeated for each second image that is printed within the respective ribbon, and

instruct the print engine to print the transformed second image in the respective ribbon of the first image.

2. The system of claim 1, further comprising:

an image sensor to capture an image of the first image that is printed, wherein the controller is to detect the failure by comparing the image that is captured to print data.

3. The system of claim 1, wherein the print engine includes a plurality of stationary printheads to print the first image.

4. The system of claim 1, wherein the controller is to perform the 180-degree rotation on a compressed representation of the second image by:

substituting compressed blocks in the compressed representation with compressed blocks corresponding to rotational variants of the compressed blocks in the compressed representation; and

rearranging the rotational variants.

5. The system of claim 4, wherein the controller is to determine the rotational variants of the compressed blocks in the compressed representation by accessing a lookup table.

6. A method, comprising:

printing a plurality of images on a medium, wherein each one of the plurality of images is printed on a respective ribbon of a plurality of ribbons on the medium, wherein each one of the plurality of ribbons comprises an elongated strip on the medium to receive a respective image that is repeated end-to-end along the elongated strip;

detecting a defect in a printed copy of an image of the plurality of images in the respective ribbon of the image while the print engine is printing the plurality of images; and

printing a transformed version of the image based on the defect that is detected in response to the defect that is detected, wherein the transformed version of the image comprises a 180-degree rotation of the image that is repeated for each transformed version of the image that is printed in the respective ribbon of the image.

7. The method of claim 6, wherein printing the transformed version of the image comprises printing a rotated version of the image on the respective ribbon and an unrotated version of another image on another ribbon of the plurality of ribbons.

8. The method of claim 7, further comprising indicating that the one of the plurality of ribbons includes the rotated version of the image, and indicating a start position of the rotated version of the image.

9. The method of claim 6, wherein detecting the defect includes identifying a printhead that failed and identifying the respective ribbon associated with the printhead that failed.

10. The method of claim 9, further comprising:

determining a location in the transformed version of the image to be aligned with the printhead that failed; and

determining an amount of print content associated with the printhead that failed in the location, wherein printing the transformed version of the image comprises printing the transformed version of the image based on the amount of print content associated with the printhead that failed being less than a threshold.

11. A non-transitory computer-readable medium comprising instructions that, when executed by a processor, cause the processor to:

detect a failure of a printhead based on a defect in a printed copy of an image in a respective ribbon of the image of a plurality of ribbons, while printing a plurality of images on a medium, wherein each one of the plurality of ribbons comprises an elongated strip on the medium to receive a respective image of a plurality of images that is repeated end-to-end along the elongated strip;

in response to the failure detection, determine whether a print quality can be improved by performing an affine transformation on an image to be printed in a respective ribbon of a plurality of ribbons of a medium; and

perform the affine transformation on the image based on a determination that the print quality can be improved, wherein the affine transformation of the image comprises a 180-degree rotation of the image that is repeated for each affine transformation of the image that is to be printed in the respective ribbon of the image.

12. The computer-readable medium of claim 11, wherein the instructions, when executed by the processor, cause the processor to analyze a captured image of a printed product to identify the printhead with the failure.

13. The computer-readable medium of claim 11, wherein the instructions, when executed by the processor, cause the processor to simulate printing with the affine transformation performed to determine whether the print quality can be improved.

14. The computer-readable medium of claim 11, wherein the instructions, when executed by the processor, cause the processor to determine whether the print quality can be improved to within a predetermined threshold of the image without defects, and perform the affine transformation on the image based on a determination the print quality can be improved within the predetermined threshold.

15. The computer-readable medium of claim 11, wherein the instructions, when executed by the processor, cause the processor to perform the affine transformation by substituting compressed blocks in a compressed representation of the image for rotational variants and output the rotational variants in a reverse order.