IMAGE PROCESSING APPARATUS, IMAGE PROCESSING METHOD, AND CAMERA MODULE

• US 20120212653A1
• Filed: 11/16/2011
• Published: 08/23/2012
• Est. Priority Date: 02/18/2011
• Status: Active Grant

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: KANEMITSU, Shiroshi, TABUCHI, Kazuhiro, KAWAKAMI, Takaaki
• Granted Patent: US 8,648,937 B2
• Time in Patent Office: Days
• US Class Current: 348/242
• CPC Class Codes: G06T 5/73 Deblurring; Sharpening
• CPC Class Codes: H04N 1/58 Edge or detail enhancement; Noise or error suppression, e.g. colour misregistration correction H04N1/62 takes precedence
• CPC Class Codes: H04N 9/646 for image enhancement, e.g. vertical detail restoration, cross-colour elimination, contour correction, chrominance trapping filters
• CPC Class Codes: H04N 9/77 Circuits for processing the brightness signal and the chrominance signal relative to each other, e.g. adjusting the phase of the brightness signal relative to the colour signal, correcting differential gain or differential phase circuits for matrixing H04N9/67

Abstract

According to one embodiment, an image processing apparatus includes a color-difference signal correction unit. The color-difference signal correction unit includes a smoothing unit and a color edge extracting unit. The smoothing unit performs smoothing process on a color-difference signal to obtain a smoothed color-difference signal. The color edge extracting unit extracts a color edge component to be added to the smoothed color-difference signal. An edge coring unit which is included in the color edge extracting unit performs a coring process on a difference between the color-difference signal before the smoothing process is performed and the smoothed color-difference signal.

Claims

1. An image processing apparatus comprising:

a signal conversion unit that converts a signal of each color component into a color-difference signal and a brightness signal; and

a color-difference signal correction unit that corrects color noise of the color-difference signal from the signal conversion unit,

wherein the color-difference signal correction unit includes

a smoothing unit that performs a smoothing process on the color-difference signal to obtain a smoothed color-difference signal, and

a color edge extracting unit that extracts a color edge component to be added to the smoothed color-difference signal, and

wherein the color edge extracting unit includes an edge coring unit that performs a coring process on a difference between the color-difference signal before the smoothing process is performed and the smoothed color-difference signal.

2. The image processing apparatus according to claim 1,

wherein the color edge extracting unit multiplies the difference by an edge gain for adjusting a weight of the color edge component with respect to the smoothed color-difference signal.

3. The image processing apparatus according to claim 1,

wherein the color-difference signal correction unit further includes a color difference coring unit that performs a coring process on the smoothed color-difference signal to which the color edge component is added.

4. The image processing apparatus according to claim 1,

wherein the color-difference signal correction unit further includes a color difference coring unit that performs a coring process on the smoothed color-difference signal before the color edge component is added.

5. The image processing apparatus according to claim 4,

wherein the edge coring unit and the color difference coring unit share a circuit structure.

6. The image processing apparatus according to claim 1,

wherein the edge coring unit performs the coring process according to the comparison result between the difference and a predetermined coring threshold value, and

the color-difference signal correction unit further includes a parameter adjusting unit that adjusts the coring threshold value according to brightness information during image capture.

7. The image processing apparatus according to claim 2,

wherein the color-difference signal correction unit further includes a parameter adjusting unit that adjusts the edge gain according to brightness information during image capture.

8. An image processing method comprising:

converting a signal of each color component into a color-difference signal and a brightness signal; and

performing a color-difference signal correction in which color noise of the color-difference signal is corrected,

wherein the color-difference signal correction includes

performing a smoothing process on the color-difference signal to obtain a smoothed color-difference signal, and

performing a color edge extraction in which a color edge component to be added to the smoothed color-difference signal is extracted, and

wherein, in the performing of the color edge component extraction, an edge coring process which is a coring process is performed on a difference between the color-difference signal before the smoothing process is performed and the smoothed color-difference signal.

9. The image processing method according to claim 8,

wherein the difference is multiplied by an edge gain for adjusting a weight of the color edge component with respect to the smoothed color-difference signal.

10. The image processing method according to claim 8,

wherein, in the color-difference signal correction, a color-difference coring process which is a coring process is performed on the smoothed color-difference signal to which the color edge component is added.

11. The image processing method according to claim 8,

wherein, in the color-difference signal correction, a color-difference coring process which is a coring process is performed on the smoothed color-difference signal before the color edge component is added.

12. The image processing method according to claim 8,

wherein the edge coring process is performed according to a comparison result between the difference and a predetermined coring threshold value, and

the coring threshold value is adjusted according to brightness information during image capture.

13. The image processing method according to claim 9,

wherein the edge gain is adjusted according to brightness information during image capture.

14. A camera module comprising:

a lens unit that receives light from an object and forms an object image;

an image sensor that captures the object image; and

an image processing apparatus that processes an image signal acquired by an imaging operation of the image sensor,

wherein the image processing apparatus includes

a signal conversion unit that converts a signal of each color component into a color-difference signal and a brightness signal, and

a color-difference signal correction unit that corrects color noise of the color-difference signal from the signal conversion unit,

wherein the color-difference signal correction unit includes

a smoothing unit that performs smoothing process on the color-difference signal to obtain a smoothed color-difference signal, and

a color edge extracting unit that extracts a color edge component to be added to the smoothed color-difference signal, and

wherein the color edge extracting unit includes an edge coring unit that performs a coring process on a difference between the color-difference signal before the smoothing process is performed and the smoothed color-difference signal.

15. The camera module according to claim 14,

wherein the color edge extracting unit multiplies the difference by an edge gain for adjusting a weight of the color edge component with respect to the smoothed color-difference signal.

16. The camera module according to claim 14,

wherein the color-difference signal correction unit further includes a color difference coring unit that performs a coring process on the smoothed color-difference signal to which the color edge component is added.

17. The camera module according to claim 14,

wherein the color-difference signal correction unit further includes a color difference coring unit that performs a coring process on the smoothed color-difference signal before the color edge component is added.

18. The camera module according to claim 17,

wherein the edge coring unit and the color difference coring unit share a circuit structure.

19. The camera module according to claim 14,

wherein the edge coring unit performs the coring process according to a comparison result between the difference and a predetermined coring threshold value, and

the color-difference signal correction unit further includes a parameter adjusting unit that adjusts the coring threshold value according to brightness information during image capture by the image sensor.

20. The camera module according to claim 15,

wherein the color-difference signal correction unit further includes a parameter adjusting unit that adjusts the edge gain according to brightness information during image capture by the image sensor.