Multi-directional structured image array capture on a 2D graph
This present disclosure relates to systems and processes for capturing an unstructured light field in a plurality of images. In particular embodiments, a plurality of keypoints are identified on a first keyframe in a plurality of captured images. A first convex hull is computed from all keypoints in the first keyframe and merged with previous convex hulls corresponding to previous keyframes to form a convex hull union. Each keypoint is tracked from the first keyframe to a second image. The second image is adjusted to compensate for camera rotation during capture, and a second convex hull is computed from all keypoints in the second image. If the overlapping region between the second convex hull and the convex hull union is equal to, or less than, a predetermined size, the second image is designated as a new keyframe, and the convex hull union is augmented with the second convex hull.
1. A method for capturing an unstructured light field in a plurality of images, the method including:
identifying a plurality of keypoints on a first keyframe in a plurality of captured images;
computing the convex hull of all keypoints in the plurality of keypoints in the first keyframe to form a first convex hull;
merging the first convex hull with previous convex hulls corresponding to previous keyframes to form a convex hull union;
keeping track of each keypoint from the first keyframe to a second image;
adjusting the second image to compensate for camera rotation during capture of the second image;
computing the convex hull of all keypoints in the second image to form a second convex hull;
if the overlapping region between the second convex hull and the convex hull union is equal to, or less than, half of the size of the second convex hull, designating the second image as a new keyframe; and
if the second image is designated as a new keyframe, augmenting the convex hull union with the second convex hull.
2. The method of claim 1 , wherein identifying the plurality of keypoints includes using Harris-style keypoint detection.
3. The method of claim 1 , wherein keeping track of each keypoint includes using KLT-style keypoint tracking.
4. The method of claim 1 , wherein adjusting the second image to compensate for camera rotation includes using internal measurement unit (IMU) data associated with the second image.
5. The method of claim 1 , wherein designating the second image as a new keyframe occurs in real-time during capture of the second image.
6. The method of claim 1 , further comprising repeating the steps until a predetermined threshold number of keyframes has been designated for the light field.
7. The method of claim 6 , further comprising representing the number of keyframes as nodes on a 2D graph.
8. A system for capturing an unstructured light field in a plurality of images, the system including:
a camera for capturing the plurality of images;
a processor, and
memory storing one or more programs configured for execution by the processor, the one or more programs comprising instructions for:
identifying a plurality of keypoints on a first keyframe in the plurality of captured images;
computing the convex hull of all keypoints in the plurality of keypoints in the first keyframe to form a first convex hull;
merging the first convex hull with previous convex hulls corresponding to previous keyframes to form a convex hull union;
keeping track of each keypoint from the first keyframe to a second image;
adjusting the second image to compensate for camera rotation during capture of the second image;
computing the convex hull of all keypoints in the second image to form a second convex hull;
if the overlapping region between the second convex hull and the convex hull union is equal to, or less than, half of the size of the second convex hull, designating the second image as a new keyframe; and
if the second image is designated as a new keyframe, augmenting the convex hull union with the second convex hull.
9. The system of claim 8 , wherein identifying the plurality of keypoints includes using Harris-style keypoint detection.
10. The system of claim 8 , wherein keeping track of each keypoint includes using KLT-style keypoint tracking.
11. The system of claim 8 , wherein adjusting the second image to compensate for camera rotation includes using internal measurement unit (IMU) data associated with the second image.
12. The system of claim 8 , wherein designating the second image as a new keyframe occurs in real-time during capture of the second image.
13. The system of claim 8 , wherein the one or more programs further comprise instructions for repeating the steps until a predetermined threshold number of keyframes has been designated for the light field.
14. The system of claim 13 , wherein the one or more programs further comprise instructions for representing the number of keyframes as nodes on a 2D graph.
15. A non-transitory computer readable medium storing one or more programs configured for execution by a computer, the one or more programs comprising instructions for:
identifying a plurality of keypoints on a first keyframe in a plurality of captured images;
computing the convex hull of all keypoints in the plurality of keypoints in the first keyframe to form a first convex hull;
merging the first convex hull with previous convex hulls corresponding to previous keyframes to form a convex hull union;
keeping track of each keypoint from the first keyframe to a second image;
adjusting the second image to compensate for camera rotation during capture of the second image;
computing the convex hull of all keypoints in the second image to form a second convex hull;
if the overlapping region between the second convex hull and the convex hull union is equal to, or less than, half of the size of the second convex hull, designating the second image as a new keyframe; and
if the second image is designated as a new keyframe, augmenting the convex hull union with the second convex hull.
16. The non-transitory computer readable medium of claim 15 , wherein identifying the plurality of keypoints includes using Harris-style keypoint detection.
17. The non-transitory computer readable medium of claim 15 , wherein keeping track of each keypoint includes using KLT-style keypoint tracking.
18. The non-transitory computer readable medium of claim 15 , wherein adjusting the second image to compensate for camera rotation includes using internal measurement unit (IMU) data associated with the second image.
19. The non-transitory computer readable medium of claim 15 , wherein designating the second image as a new keyframe occurs in real-time during capture of the second image.
20. The non-transitory computer readable medium of claim 15 , wherein the one or more programs further comprise instructions for repeating the steps until a predetermined threshold number of keyframes has been designated for the light field.