Image processing apparatus, image processing method, image pickup apparatus, computer program and recording medium

• US 20060132642A1
• Filed: 12/16/2005
• Published: 06/22/2006
• Est. Priority Date: 12/22/2004
• Status: Active Grant

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Kasai, Masanori, Hosaka, Hajime
• Granted Patent: US 7,589,771 B2
• Time in Patent Office: Days
• US Class Current: 348/370
• CPC Class Codes: H04N 23/11 for generating image signals from visible and infrared light wavelengths
• CPC Class Codes: H04N 23/80 Camera processing pipelines; Components thereof
• CPC Class Codes: H04N 23/81 for suppressing or minimising disturbance in the image signal generation

Abstract

Noises are reduced in an image picked up in natural light without using lighting equipment that affect the picked up image. The present invention provides an image processing apparatus that includes an image acquisition unit that acquires a visible light image and an invisible light image corresponding to the visible light image, and a noise reduction unit that reduces noises of the visible light image by using the invisible light image.

Claims

1. An image processing apparatus comprising:

image acquisition means for acquiring a visible light image and an invisible light image corresponding to the visible light image; and

noise reduction means for reducing noises of the visible light image by using the invisible light image.

2. The apparatus according to claim 1, wherein

the noise reduction means includes:

first filtering means for applying a low pass filter to the visible light image;

second filtering means for applying a high pass filter to the invisible light image; and

synthesis means for synthetically combining the output of the low pass filter and the output of the high pass filter.

3. The apparatus according to claim 1, wherein the invisible light image is an infrared image.

4. The apparatus according to claim 1, wherein the invisible light image is an ultraviolet image.

5. The apparatus according to claim 1, wherein the low pass filter is an edge preserving low pass filter.

6. The apparatus according to claim 5, wherein the edge preserving low pass filter removes noises from the visible light image, while preserving the edges detected from the invisible light image.

7. The apparatus according to claim 6, wherein noises are removed from the visible light image by means of a plurality of low pass filters of different levels.

8. The apparatus according to claim 7, wherein noises are removed from the visible light image by means of one of the plurality of low pass filters of different levels selected according to the evaluation value of the edges detected from the invisible light image.

9. The apparatus according to claim 8, wherein the level of the selected low pass filter is determined independently both in the X-direction and in the Y-direction of the image.

10. The apparatus according to claim 2, wherein the visible light image is transformed into a color image and a luminance image and filters are applied respectively to the color image and the luminance image obtained as a result of transformation.

11. The apparatus according to claim 10, wherein a bilateral filter is applied to the color image and a cross bilateral filter is applied to the luminance image.

12. The apparatus according to claim 1, further comprising:

aberration correction means for correcting the aberration of the visible light image and that of the invisible light image.

13. The apparatus according to claim 12, wherein the aberration correction means correct the aberrations, using the error between the luminance image obtained by transforming the visible light image and the invisible light image.

14. An image pickup apparatus comprising:

visible light image pickup means for picking up a visible light image according to a first spectral characteristic of having sensitivity mainly relative to visible light;

invisible light image pickup means for picking up an invisible light image according to a second spectral characteristic of having sensitivity mainly to invisible light;

aberration correction means for correcting the aberration of the visible light image and that of the invisible light image; and

noise reduction means for reducing noises of the visible light image by using the invisible light image.

15. An image processing method comprising:

an image acquisition step of acquiring a visible light image and an invisible light image corresponding to the visible light image and picked up with the same number of pixel as those of the visible light image; and

a noise reduction step of reducing noises of the visible light image by using the invisible light image.

16. A computer program for causing a computer to execute a predetermined process, the program comprising:

an image acquisition step of acquiring a visible light image and an invisible light image corresponding to the visible light image and picked up with the same number of pixel as those of the visible light image; and

a noise reduction step of reducing noises of the visible light image by using the invisible light image.

17. A recording medium where a computer program for causing a computer to execute a predetermined process, the program comprising:

an image acquisition step of acquiring a visible light image and an invisible light image corresponding to the visible light image and picked up with the same number of pixel as those of the visible light image; and

a noise reduction step of reducing noises of the visible light image by using the invisible light image.

18. An image processing apparatus comprising:

an image acquisition unit that acquires a visible light image and an invisible light image corresponding to the visible light image; and

a noise reduction unit that reduces noises of the visible light image by using the invisible light image.

19. An image pickup apparatus comprising:

a visible light image pickup unit that picks up a visible light image according to the first spectral characteristic of having sensitivity mainly relative to visible light;

an invisible light image pickup unit that picks up an invisible light image according to the second spectral characteristic of having sensitivity mainly to invisible light;

an aberration correction unit that corrects the aberration of the visible light image and that of the invisible light image; and

a noise reduction unit that reduces noises of the visible light image by using the invisible light image.