Reducing color artifacts in plenoptic imaging systems

Patent metadata

Field	Value
Publication number	US-10552942-B2
Application number	US-201715699733-A
Country	US
Kind code	B2
Filing date	Sep 8, 2017
Priority date	Sep 8, 2017
Publication date	Feb 4, 2020
Grant date	Feb 4, 2020

Abstract

In one aspect, a color plenoptic imaging system captures a plenoptic image of an object. The plenoptic image is made up of a plurality of superpixels, and each superpixel includes a center subpixel. The collection of center subpixels from the plurality of superpixels forms a set of captured center view data for the object. The sensor array includes at least two arrays of different color sensors that capture subpixels of different colors. The microlens array and the sensor array are positioned such that, within the set of captured center view data, for each of the different colors, adjacent center subpixels of that color are separated by not more than three intervening center subpixels of a different color.

First claim

What is claimed is:

1. A color plenoptic imaging system comprising:
imaging optics that image an object onto an image plane of the imaging optics, the imaging optics characterized by a pupil located at a pupil plane;
a microlens array located at the image plane of the imaging optics; and
a rotatable sensor array located at a conjugate to the pupil plane, the microlens array imaging the pupil plane onto the sensor array, the sensor array capturing a plenoptic image of the object, the plenoptic image comprising a plurality of superpixels, each superpixel including a center subpixel, the collection of center subpixels from the plurality of superpixels forming a set of captured center view data for the object;
wherein:
the rotatable sensor array comprises at least two arrays of different color sensors that capture subpixels of different colors; and
the rotatable sensor array is rotated relative to the microlens array such that:
(i) within the set of captured center view data, for each of the different colors, adjacent center subpixels of that color are separated by not more than three intervening center subpixels of a different color, and
(ii) a number of adjacent center subpixels that are the same color is reduced.

2. The plenoptic imaging system of claim 1 wherein, within the set of captured center view data, for each of the different colors, adjacent center subpixels of that color are separated by not more than two intervening center subpixels of a different color.

3. The plenoptic imaging system of claim 1 wherein, within the set of captured center view data, for each of the different colors, adjacent center subpixels of that color are separated by not more than one intervening center subpixel of a different color.

4. The plenoptic imaging system of claim 1 wherein the microlens array and the sensor array are rotated relative to each other such that, within the plenoptic image, adjacent center subpixels are not in a same row of subpixels.

5. The plenoptic imaging system of claim 1 wherein the sensor array comprises arrays of red, green and blue color sensors.

6. The plenoptic imaging system of claim 1 wherein the sensor array comprises an array of visible color sensors and an array of infrared sensors.

7. The plenoptic imaging system of claim 1 wherein the captured center view data is used to generate a preview image of what the plenoptic imaging system captures.

8. The plenoptic imaging system of claim 7 wherein the preview image is a color image interpolated from the center subpixels.

9. The plenoptic imaging system of claim 1 further comprising:
a color filter array with one color filter for each microlens in the microlens array; the color filters consisting of red, green and blue color filters arranged in a Bayer pattern.

10. The plenoptic imaging system of claim 1 , wherein the sensor array containing the color sensors is defined by an x axis and a y axis; and,
within the plenoptic image, either a horizontal separation Δx or a vertical separation Δy between adjacent center subpixels is an odd number of subpixels, plus or minus a quarter subpixel.

11. The plenoptic imaging system of claim 10 wherein the sensor array comprises red, green and blue color sensors arranged in a Bayer pattern.

12. The plenoptic imaging system of claim 1 wherein the microlenses are arranged in an array defined by a first principal axis and a second principal axis; either a horizontal separation Δ x1 or a vertical separation Δ y1 between center subpixels that are adjacent along the first principal axis is an odd number of subpixels, plus or minus a quarter subpixel; and either a horizontal separation Δ x2 or a vertical separation Δ y2 between center subpixels that are adjacent along the second principal axis is also an odd number of subpixels, plus or minus a quarter subpixel.

13. The plenoptic imaging system of claim 12 wherein (Δ x1 +Δ y1 ) is an odd number of subpixels, plus or minus a quarter subpixel; and (Δ x2 +Δ y2 ) is an odd number of subpixels, plus or minus a quarter subpixel.

14. The plenoptic imaging system of claim 1 wherein the superpixels are arranged in a hexagonal array.

Assignees

• Kumar Aashish
• Martinello Manuel
• Ricoh Co Ltd

Inventors

• Kumar Aashish
• Martinello Manuel

Classifications

• G06T3/4015 Primary

  Image demosaicing, e.g. colour filter arrays [CFA] or Bayer patterns · CPC title

• G06T2207/10024

  Color image · CPC title

• H04N25/134

  based on three different wavelength filter elements · CPC title

• H04N23/957

  Light-field or plenoptic cameras or camera modules · CPC title

• H04N9/04

  Electricity · mapped topic