Pixel correction

Patent metadata

Field	Value
Publication number	US-11228723-B2
Application number	US-202016791001-A
Country	US
Kind code	B2
Filing date	Feb 14, 2020
Priority date	Mar 5, 2019
Publication date	Jan 18, 2022
Grant date	Jan 18, 2022

Abstract

A method and apparatus for image processing, the method comprising obtaining input image data comprising a plurality of pixel intensity values representing a respective plurality of pixel locations, obtaining pixel location data identifying one or more pixel locations represented by compromised pixel intensity values, generating interpolated image data comprising improved pixel intensity values, storing improved image data comprising at least the interpolated image data, and detecting one or more further compromised pixel intensity values based on the improved image data.

First claim

What is claimed is:

1. A computer-implemented method comprising:
obtaining input image data representative of at least a portion of an image, the input image data comprising a plurality of pixel intensity values representing a respective plurality of pixel locations;
obtaining pixel location data identifying a first set of one or more pixel locations represented by one or more respective compromised pixel intensity values;
generating interpolated image data comprising one or more improved pixel intensity values representing the one or more identified pixel locations based on the input image data and the pixel location data, wherein the one or more improved pixel intensity values are generated at least by interpolation of pixel intensity values representing selected neighboring pixel locations;
storing improved image data comprising at least the interpolated image data; and
detecting a second set of one or more further pixel locations represented by one or more respective compromised pixel intensity values based on the improved image data including the one or more improved pixel intensity values, wherein the second set of one or more further pixel locations are different to the first set of one or more pixel locations.

2. The computer-implemented method of claim 1 , wherein the pixel location data identifies one or more static defect pixel locations.

3. The computer-implemented method of claim 1 , wherein the pixel location data identifies one or more phase detection autofocus pixel locations.

4. The computer-implemented method of claim 1 , wherein the pixel location data identifies one or more static defect pixel locations and one or more phase detection autofocus pixel locations.

5. The computer-implemented method of claim 4 , wherein obtaining the pixel location data comprises generating the pixel location data based on predetermined phase detection autofocus pixel locations and predetermined static defect pixel locations.

6. The computer-implemented method of claim 1 , wherein the selected neighboring pixel locations do not include pixel locations identified by the pixel location data.

7. The computer-implemented method of claim 6 , wherein the selected neighboring pixel locations are determined by selecting a linear arrangement of neighboring pixel locations.

8. The computer-implemented method of claim 1 , wherein the selected neighboring pixel locations are determined by selecting a linear arrangement of neighboring pixel locations.

9. The computer-implemented method of claim 1 , wherein storing improved image data comprises:
storing improved pixel intensity values of the interpolated image data representing pixel locations identified by the pixel location data; and
storing pixel intensity values of the input image data representing pixel locations not identified by the pixel location data.

10. The computer-implemented method of claim 1 , wherein detecting the second set of one or more further pixel locations represented by one or more respective compromised pixel intensity values based on the improved image data comprises determining for a first pixel location represented by a first pixel intensity value of the improved image data whether the first pixel intensity value is a compromised pixel intensity value based at least on the first pixel intensity value and one or more pixel intensity values of the improved image data representing a first set of neighboring pixel locations.

11. The computer-implemented method of claim 10 , further comprising:
generating a first corrected pixel intensity value representing the first pixel location; and
storing corrected image data comprising at least the first corrected pixel intensity value representing the first pixel location.

12. The computer-implemented method of claim 11 , wherein generating a first corrected pixel intensity value comprises:
if the first pixel intensity value of the improved image data representing the first pixel location is a compromised pixel intensity value, generating the first corrected pixel intensity value based on pixel intensity values of the improved image data representing a second set of neighboring pixel locations and the first pixel intensity value; or
if the first pixel intensity value of the improved image data representing the first pixel location is not a compromised pixel intensity value, selecting the first pixel intensity value of the improved image data representing the first pixel location.

13. The computer-implemented method of claim 12 , wherein the first set of neighboring pixel locations and the second set of neighboring pixel locations comprise the same pixel locations.

14. The computer-implemented method of claim 11 , wherein detecting the second set of one or more further pixel locations represented by one or more respective compromised pixel intensity values based on the improved image data comprises determining for a second pixel location represented by a second pixel intensity value of the corrected image data whether the second pixel intensity value is a compromised pixel intensity value based at least on the second pixel intensity value and one or more pixel intensity values of the corrected image data representing a third set of neighboring pixel locations.

15. The computer-implemented method of claim 14 , further comprising:
generating a second corrected pixel intensity value representing the second pixel location; and
updating the corrected image data based on the second corrected pixel intensity value representing the second pixel location.

16. The computer-implemented method of claim 15 , wherein generating a second corrected pixel intensity value comprises:
if the second pixel intensity value of the corrected image data representing the second pixel location is a compromised pixel intensity value, generating the second corrected pixel intensity value based on pixel intensity values of the corrected image data representing a fourth set of neighboring pixel locations and the second pixel intensity value; or
if the second pixel intensity value of the corrected image data representing the second pixel location is not a compromised pixel intensity value, selecting the second pixel intensity value of the corrected image data representing the second pixel location.

17. The computer-implemented method of claim 16 , wherein the third set of neighboring pixel locations and the fourth set of neighboring pixel locations comprise the same neighboring pixel locations.

18. An apparatus comprising:
at least one processor;
at least one memory including computer program code, the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus at least to:
obtain input image data representative of at least a portion of an image, the input image data comprising a plurality of pixel intensity values representing a respective plurality of pixel locations;
obtain pixel location data identifying a first set of one or more pixel locations represented by one or more respective compromised pixel intensity values;
generate interpolated image data comprising one or more improved pixel intensity values representing the one or more identified pixel locations based on the input image data and the pixel location data, wherein the one or more improved pixel intensity values are generated at least by interpolation of pixel intensity values representing selected neighboring pixel locations;
store improved image data comprising at least the interpolated image data; and
detect a second set of one or more further pix

Assignees

• Apical Ltd

Inventors

• Hanwell David
• Yildiz Nerhun

Classifications

• H04N25/671

  for non-uniformity detection or correction · CPC title

• H04N25/683 Primary

  by defect estimation performed on the scene signal, e.g. real time or on the fly detection · CPC title

• H04N23/81

  for suppressing or minimising disturbance in the image signal generation · CPC title

• H04N25/13

  characterised by the spectral characteristics of the filter elements · CPC title

• H04N25/11

  Arrangement of colour filter arrays [CFA]; Filter mosaics · CPC title