Producing full-color image using CFA image

• US 8,068,153 B2
• Filed: 03/27/2009
• Issued: 11/29/2011
• Est. Priority Date: 03/27/2009
• Status: Active Grant

• Current Assignee: Omnivision Technologies Incorporated (Will Semiconductor Co., Ltd. Shanghai)
• Original Assignee: Omnivision Technologies Incorporated (Will Semiconductor Co., Ltd. Shanghai)
• Inventors: Adams, James E. Jr., Kumar, Mrityunjay
• Primary Examiner(s): Pasiewicz; Daniel M
• Application Number:
  US12/412,429
• Publication Number:
  US 20100245636A1
• Time in Patent Office: 977 Days
• Field of Search: 348/208.4, 348/208.6, 348/208.12, 348/208.13, 348/222.1, 348/241, 348/242, 348/273, 348/276, 348/277, 348/279, 382/167
• US Class Current: 348/242
• CPC Class Codes: G06T 3/4015 Image demosaicing, e.g. colour filter arrays [CFA] or Bayer patterns
• CPC Class Codes: H04N 23/68 for stable pick-up of the scene, e.g. compensating for camera body vibrations
• CPC Class Codes: H04N 25/133 including elements passing panchromatic light, e.g. filters passing white light
• CPC Class Codes: H04N 25/135 based on four or more different wavelength filter elements

Abstract

A method of forming a full-color output image using a color filter array image having a plurality of color channels and a panchromatic channel, comprising capturing a color filter array image having a plurality of color channels and a panchromatic channel, wherein the panchromatic channel is captured using a different exposure time than at least one of the color channels; computing an interpolated color image and an interpolated panchromatic image from the color filter array image; computing a chrominance image from the interpolated color image; and forming the full color output image using the interpolated panchromatic image and the chrominance image.

Claims

1. A method of forming a full-color output image using a color filter array image having a plurality of color channels and a panchromatic channel, comprising one or more processors for providing the following:

a) capturing the color filter array image using a color filter array image sensor, the color filter array image having the plurality of color channels and the panchromatic channel, wherein the panchromatic channel is captured using a different exposure time than at least one of the plurality of color channels of the color filter array image;

b) computing an interpolated color image and an interpolated panchromatic image from the color filter array image;

c) computing a chrominance image from the interpolated color image, wherein computing the chrominance image includes

computing a synthetic panchromatic image from the interpolated color image, and

modifying the chrominance image as a function of the synthetic panchromatic image and the interpolated panchromatic image; and

d) forming the full-color output image using the interpolated panchromatic image and the chrominance image.

2. The method of claim 1 wherein the interpolated color image having a plurality of color channels, the plurality of color channels of the interpolated color image are red, green and blue.

3. The method of claim 1 wherein the interpolated color image having a plurality of color channels, the plurality of color channels of the interpolated color image are cyan, magenta and yellow.

4. The method of claim 1 wherein the synthetic panchromatic image is computed by performing a weighted summation of a plurality of color channels of the interpolated color image.

5. The method of claim 4 wherein the weights used in the weighted summation are determined from spectral responses of the color channels and the panchromatic channel.

6. The method of claim 1 wherein the chrominance image is modified using a ratio of the interpolated panchromatic image and the synthetic panchromatic image.

7. The method of claim 6 wherein the chrominance image is modified by multiplying the chrominance image by the ratio of the interpolated panchromatic image and the synthetic panchromatic image.

9. The method of claim 1 wherein the full-color output image is formed by combining the interpolated panchromatic image and the chrominance image.

10. The method of claim 1 wherein the full-color output image has a reduced level of motion blur relative to the interpolated color image.

8. The method of claim wherein red green and blue color channels for the full-color output image are determined by performing a weighted summation of the interpolated panchromatic image and color channels of the chrominance image.