Apparatus and system for improving image quality

• US 8,368,741 B2
• Filed: 06/27/2007
• Issued: 02/05/2013
• Est. Priority Date: 06/27/2007
• Status: Expired due to Fees

• Current Assignee: Google Technology Holdings LLC (Alphabet Inc.)
• Original Assignee: General Instrument Corporation (CommScope Holding Company, Inc.)
• Inventors: Jelley, Kevin W., Lin, Ruei-Sung, Tang, Bei
• Primary Examiner(s): MILLER, BRANDON J
• Application Number:
  US11/769,002
• Publication Number:
  US 20090002475A1
• Time in Patent Office: 2,050 Days
• Field of Search: 348 1412- 1415, 348 1401- 1402, 348 1407- 1409
• US Class Current: 348/14.12
• CPC Class Codes: H04N 23/56 provided with illuminating means
• CPC Class Codes: H04N 25/581 acquired simultaneously
• CPC Class Codes: H04N 5/33 Transforming infrared radiation cameras or camera modules for generating image signals from infrared radiation H04N23/20; circuitry of SSIS for transforming infrared radiation into image signals H04N25/20
• CPC Class Codes: H04N 7/142 Constructional details of the terminal equipment, e.g. arrangements of the camera and the display

Abstract

A system and an apparatus for improving image quality of an object in video telephony are described. The apparatus comprises an image detection unit, an image alignment unit and an image fusion unit. A near infrared light source in the image detection unit illuminates the object, such that the object is front illuminated. An image sensor alongside the near infrared light source generates a near infrared image and a visible image. An image alignment unit aligns the near infrared image and the visible image. An image fusion unit fuses the aligned near infrared image and aligned visible image pair to form a composite image of the object. The composite image of the object has improved image quality, image detail, and a reduction in shadows.

Claims

1. An apparatus for improving image quality in video telephony comprising:

an image detection unit, wherein the image detection unit comprises;

a near infrared light source for illuminating an object, such that the object is front illuminated thereby producing reflected near infrared radiation, an image sensor for generating first image data responsive to the reflected near infrared radiation,

an infrared filter for filtering the reflected near infrared radiation while allowing reflected visible light from the object, wherein the image sensor further generates second image data responsive to the reflected visible light when the infrared filter is active;

an image alignment unit coupled to the image sensor of the image detection unit for aligning a near infrared image from the first image data with a visible image from the second image data in order to form an aligned image pair; and

an image fusion unit for forming a composite image of the object from the aligned image pair.

2. The apparatus of claim 1, further comprising a visible light source for illuminating the object thereby producing the reflected visible light.

3. The apparatus of claim 1, wherein the near infrared image and the visible image generated by the image sensor are interleaved.

4. The apparatus of claim 1, further comprising a second image sensor for generating the first image data responsive to the reflected near infrared radiation.

5. The apparatus of claim 1, wherein the near infrared light source emits near infrared radiation, such that reflected near infrared radiation is produced from the object on which the near infrared radiation is incident.

6. The apparatus of claim 1, further comprising an optical system to focus the reflected visible light and the reflected near infrared radiation from the object on to the image sensor.

7. The apparatus of claim 1, wherein the image alignment unit forms the aligned image pair by applying linear spatial transformation on the near infrared image and the visible image.

8. The apparatus of claim 1, wherein the image alignment unit forms the aligned image pair by applying temporal interpolation on the near infrared image.

9. The apparatus of claim 1, wherein the image fusion unit comprises:

a first color space converter for converting color components of the aligned visible image into chrominance values, and a luminance value;

a weighted averaging unit for calculating a weighted average of the aligned visible image luminance value and an aligned near infrared image luminance value; and

a second color space converter for converting the chrominance values and the weight-averaged luminance values into color components to form the composite image.

10. The apparatus of claim 1, wherein the image detection unit, the image alignment unit, and the image fusion unit are embedded in a camera.

11. An apparatus for improving image quality in video telephony comprising:

an image detection unit, wherein the image detection unit comprises;

a near infrared light source for illuminating an object, such that the object is front illuminated thereby producing reflected near infrared radiation,

a first image sensor for generating a near infrared image responsive to the reflected near infrared radiation, and

a second image sensor coupled to an infrared filter for generating a visible image responsive to reflected visible light when the infrared filter is active,

wherein the first image sensor and the second image sensor share a common optical system;

an image alignment unit coupled to the first image sensor and the second image sensor to align the visible image with the near infrared image using linear spatial alignment, in order to form an aligned image pair; and

an image fusion unit for forming a composite image of the object from the aligned image pair.

12. The apparatus of claim 11, wherein the image detection unit, the image alignment unit, and the image fusion unit are embedded in a camera coupled to a communication terminal.

13. The apparatus of claim 11, further comprising a visible light source for illuminating the object thereby producing the reflected visible light.

14. The apparatus of claim 11, wherein the infrared filter blocks the reflected near infrared radiation from the object to the second image sensor when the infrared filter is active.

15. The apparatus of claim 11, wherein the infrared filter is continuously in an active state.

16. The apparatus of claim 11, wherein the image alignment unit forms the aligned image pair by applying linear spatial transformation on the near infrared image and the visible image.

17. The apparatus of claim 11, wherein the image fusion unit comprises:

a first color space converter for converting color components of the aligned visible image into chrominance values, and a luminance value;

a weighted averaging unit for calculating a weighted average of the aligned visible image luminance value and an aligned near infrared image luminance value; and

a second color space converter for converting the chrominance values and the weight-averaged luminance values into color components to form the composite image.

18. A system for improving image quality in video telephony comprising:

a camera, wherein the camera comprises

an image detection unit comprising

a near infrared light source for illuminating an object, such that the object is front illuminated thereby producing reflected near infrared radiation,

an image sensor for generating first image data responsive to the reflected near infrared radiation,

an infrared filter for filtering the reflected near infrared radiation while allowing reflected visible light from the object, wherein the image sensor further generates second image data responsive to the reflected visible light when the infrared filter is active;

an image alignment unit coupled to the image sensor of the image detection unit to align a near infrared image from the first image data with a visible image from the second image data in order to form an aligned image pair; and

an image fusion unit for forming a composite image of the object from the aligned image pair;

a communication terminal coupled to the camera to receive the composite image from the image fusion unit of the camera and to transmit the composite image to a communication line,

a video display unit coupled to the communication terminal for displaying images of the object.

19. The system of claim 18, wherein the camera further comprises a second image sensor for generating the first image data responsive to the reflected near infrared radiation.

20. The system of claim 18, wherein the communication line transmits the composite image to an end user.