Apparatus and method for capturing still images and video using coded lens imaging techniques

• US 8,288,704 B2
• Filed: 09/06/2011
• Issued: 10/16/2012
• Est. Priority Date: 01/18/2005
• Status: Active Grant

• Current Assignee: Rearden, LLC
• Original Assignee: Rearden, LLC
• Inventors: Perlman, Stephen G., Busboom, Axel, Cotter, Tim S., Speck, John, van der Laan, Roger, Greene, Pamela
• Primary Examiner(s): LUU, THANH X
• Application Number:
  US13/226,461
• Publication Number:
  US 20110315855A1
• Time in Patent Office: 406 Days
• Field of Search: 250/216, 250/208.1, 250/363.06
• US Class Current: 250/216
• CPC Class Codes: H04N 23/957 Light-field or plenoptic cameras or camera modules
• CPC Class Codes: H04N 25/60 Noise processing, e.g. detecting, correcting, reducing or removing noise
• CPC Class Codes: H04N 25/61 the noise originating only from the lens unit, e.g. flare, shading, vignetting or "cos4"

Abstract

An apparatus for capturing images. In one embodiment, the apparatus comprises: a coded lens array including a plurality of lenses arranged in a coded pattern and with opaque material blocking array elements that do not contain lenses; and a light-sensitive semiconductor sensor coupled to the coded lens array and positioned at a specified distance behind the coded lens array, the light-sensitive sensor configured to sense light transmitted through the lenses in the coded lens array.

Claims

1. An apparatus for coding images comprising:

a light-sensitive sensor configured to detect visible light representing a scene;

a coded lens array including a plurality of lenses arranged in a first dimension and a second dimension and coupled together to form a two dimensional coded pattern cyclically repeated at least once in both dimensions;

wherein the coded pattern is arranged to cause an overlapping of images projected from lenses onto the light-sensitive sensor;

an analog to digital converter electrically coupled to the light sensitive sensor, the A/D converter to convert an analog signal representing visible light detected by the light-sensitive sensor to a digital signal; and

an image reconstruction processor to process the digital signal and generate a reconstructed image of the scene, the reconstruction processor including program code and/or circuitry to compensate for the different levels of attenuation by adjusting intensity at different regions of the reconstructed image.

2. The apparatus as in claim 1 wherein the light-sensitive sensor is a light-sensitive semiconductor sensor coupled to the coded lens array and positioned at a specified distance behind the coded lens array, the light-sensitive sensor configured to sense light transmitted through the lenses in the coded lens array.

3. The apparatus as in claim 1 wherein the coded pattern is a Uniformly Redundant Array (URA) pattern.

4. The apparatus as in claim 1 wherein the coded pattern is a Modified Uniformly Redundant Array (MURA) pattern.

5. The apparatus as in claim 1 wherein the coded pattern is a random pattern.

6. The apparatus as in claim 1 wherein there is opaque material blocking array elements which do not contain lenses.

7. The apparatus as in claim 2 further comprising:

an image sensor readout subsystem communicatively coupled to receive image data from the light-sensitive semiconductor sensor and to dynamically_adjust zero offset and/or gain of pixel values of the image data.

8. The apparatus as in claim 1 wherein the coded pattern is a Perfect Binary Array (PBA) pattern.

9. The apparatus as in claim 1 wherein adjusting intensity at different regions of the reconstructed image comprises multiplying each pixel of the reconstructed image by an inverse of a baffle attenuation value the pixel was subjected to.

10. The apparatus as in claim 1 wherein the light sensitive sensor is approximately ¼

the size of the coded lens array.

11. The apparatus as in claim 1 wherein the lenses within the coded lens array are plano-convex lenses.

12. The apparatus as in claim 1 wherein the image reconstruction processor further comprises:

a noise-reducing smoothing filter having a filter characteristic adjusted for each pixel or each region of the reconstructed image according to signal-to-noise ratio variations within the reconstructed image.

13. The apparatus as in claim 1 wherein the light-sensitive sensor comprises a color filter array (“

CFA”

) for capturing color images.

14. The apparatus as in claim 1 wherein the light-sensitive sensor comprises a multi-layer color image sensor.

15. The apparatus as in claim 1 further comprising:

a plurality of baffles arranged in front of or behind each lens of the plurality of lenses to establish a maximum angle at which visible light of the scene can pass through the coded lens array and reach the light-sensitive sensor, the baffles causing baffle attenuation resulting in a different level of intensity of the visible light at different regions of the light-sensitive sensor, wherein each of the baffles comprise opaque material forming an apertures having a specified shape and size to establish the maximum angles at which the visible light from the scene can pass through the lens and reach the sensor.

16. The apparatus as in claim 15 wherein the aperture formed by each baffle are polygonally shaped.

17. The apparatus as in claim 15 wherein the plurality of baffles are formed out of a solid opaque material.