Refocusing images using scene captured images
A method of providing a refocused image, includes using a processor to perform the steps of acquiring at least two captured images of a scene with differing focus settings, using the at least two captured images to provide an all-in-focus image, generating a range map from the at least two captured images, locating a region-of-interest (ROI) window from the range map, and providing a refocused image from the all-in-focus image and the region-of-interest (ROI) window.
1. A method of providing a refocused image, comprising using a processor to perform the steps of
(a) acquiring at least two captured images of a scene with differing focus settings;
(b) using the at least two captured images to provide an all-in-focus image;
(c) generating a range map from the at least two captured images;
(d) locating a region-of-interest (ROI) window from the range map including locating a first centroid of a region-of-interest (ROI) from the range map, refining the first centroid to locate a second centroid of a region of interest (ROI), and locating the region-of-interest (ROI) window from the second centroid and a predefined window shape and size; and
(e) providing a refocused image from the all-in-focus image and the region-of-interest (ROI) window.
2. The method of claim 1 wherein step (b) further includes identifying extreme pixels values from the captured images and producing the all-in-focus image from the extreme pixels values.
3. The method of claim 1 wherein step (c) further includes calculating at least one difference image from the captured images and thresholding the difference images to generate the range map.
4. The method of claim 1 wherein step (a) further includes acquiring a fully out of focus image of the scene.
5. The method of claim 4 wherein step (e) further includes producing the refocused image from the all-in-focus image, the fully out of focus image, and the region-of-interest (ROI) window.
6. The method of claim 2 wherein the extreme pixel values are minimum and maximum pixel values.
7. The method of claim 2 further including averaging the extreme pixel values to produce the all-in-focus image.
8. The method of claim 3 further including generating at least two modified range maps indicating at least two different scene distances.
9. The method of claim 8 further including generating the range map from one of the modified range maps.
10. The method of claim 1 further including a predefined polygonal or elliptical window shape.
11. The method of claim 1 further including a window size equal to one-quarter the size of the all-in-focus image.
12. The method of claim 1 further including refining the region-of-interest (ROI) window shape and size.
13. A method of providing a refocused image, comprising using a processor to perform the steps of
(a) acquiring at least two captured images of a scene with differing focus settings;
(b) using the at least two captured images to provide an all-in-focus image;
(c) generating a range map from the at least two captured images;
(d) locating a region-of-interest (ROI) window from the range map; and
(e) providing a refocused image from the all-in-focus image and the region-of-interest (ROI) window including providing a low-pass all-in-focus image from the all-in-focus image and producing the refocused image from the all-in-focus image, low-pass all-in-focus image, and the region-of-interest (ROI) window.
14. A method of providing a refocused image, comprising using a processor to perform the steps of
(a) acquiring at least two captured images of a scene with differing focus settings at least one of which is a fully out of focus image of the scene;
(b) using the at least two captured images to provide an all-in-focus image;
(c) generating a range map from the at least two captured images;
(d) locating a region-of-interest (ROI) window from the range map; and
(e) providing a refocused image from the all-in-focus image, the region-of-interest (ROI) window, and at least one fully out of focus image.