Large depth-of-field microscopic structured-light 3D imaging
AssigneePurdue Research Foundation
InventorsSong Zhang, Liming Chen
Life of this patent
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Abstract
Systems and methods of large depth-of-field microscopic structured-light 3D imaging include and/or implement capturing a plurality of images of a scene using a plurality of focus settings, each of the plurality of images corresponding to one of the plurality of focus settings, the plurality of images corresponding to a focal stack; processing the plurality of images; merging the plurality of images into an all-in-focus phase map; and reconstructing a 3D shape of the scene based on the all-in-focus phase map.
Claims20
A method of capturing a three-dimensional (3D) image, the method comprising:
- capturing a plurality of images of a scene using a plurality of focus settings, each of the plurality of images corresponding to one of the plurality of focus settings, the plurality of images corresponding to a focal stack, wherein the operation of capturing includes capturing, by a camera, a plurality of fringe images with different frequencies;
- processing the plurality of images, wherein the operation of processing includes:
- computing a high-frequency phase map and a lower-frequency phase map for respective ones of the plurality of fringe images,
- estimating, using the lower-frequency phase map, affine warps that minimize a phase difference between different focus settings of the camera,
- applying the affine warps to the high-frequency phase map to generate an aligned fringe contrast map, and
- measuring, using the aligned fringe contrast map, a focus level for a plurality of pixels of an image sensor of the camera;
- merging the plurality of images into an all-in-focus phase map;
- and
- reconstructing a 3D shape of the scene based on the all-in-focus phase map.
An imaging system, comprising:
- a projector configured to emit a projection light;
- a first optical system configured to direct the projection light from the projector to a stage on which an imaging target is located;
- an image sensor configured to receive an imaging light;
- a second optical system configured to direct the imaging light from the stage to the image sensor;
- and
- a controller configured to cause the system to perform operations comprising:
- capturing a plurality of images of the imaging target using a plurality of focus settings, each of the plurality of images corresponding to one of the plurality of focus settings, the plurality of images corresponding to a focal stack, wherein the operation of capturing includes capturing, by the image sensor, a plurality of fringe images with different frequencies,
- processing the plurality of images, wherein the operation of processing includes:
- computing a high-frequency phase map and a lower-frequency phase map for respective ones of the plurality of fringe images,
- estimating, using the lower-frequency phase map, affine warps that minimize a phase difference between different focus settings of the image sensor,
- applying the affine warps to the high-frequency phase map to generate an aligned fringe contrast map, and
- measuring, using the aligned fringe contrast map, a focus level for a plurality of pixels of the image sensor,
- merging the plurality of images into an all-in-focus phase map, and
- reconstructing a three-dimensional (3D) shape of the imaging target based on the all-in-focus phase map.
Dependencies are inferred from the claim text.