Image processing apparatus, image processing method, and storage medium
An apparatus includes at least one processor configured to function as following units including a first difference extraction unit configured to extract a first difference between a plurality of images, an alignment unit configured to correct a position of an image with reference to a predetermined subject within the plurality of images, a second difference extraction unit configured to extract a second difference between the plurality of images after the position of the image is corrected by the alignment unit, and a detection unit configured to detect a moving object area based on the extracted first difference and the extracted second difference.
1. An apparatus comprising:
at least one processor configured to function as following units:
a first difference extraction unit configured to extract a first difference between a plurality of images;
an alignment unit configured to correct a position of an image with reference to a predetermined subject within the plurality of images;
a second difference extraction unit configured to extract a second difference between the plurality of images after the position of the image is corrected by the alignment unit; and
a detection unit configured to detect a moving object area based on the extracted first difference and the extracted second difference.
2. The apparatus according to claim 1 , wherein the detection unit detects a portion that is common to the first difference and the second difference as the moving object area.
3. The apparatus according to claim 1 , wherein the plurality of images are two images temporally adjacent to each other in terms of image capturing time.
4. The apparatus according to claim 3 , wherein the alignment unit uses either of the two images as a reference to align a temporally adjacent image.
5. The apparatus according to claim 1 , wherein the alignment unit calculates a motion vector of the predetermined subject to perform alignment.
6. The apparatus according to claim 1 , wherein the first difference extraction unit and the second difference extraction unit evaluate at least one of color and brightness.
7. The apparatus according to claim 1 , wherein the predetermined subject is a star.
8. The apparatus according to claim 1 , further comprising a combining unit configured to combine the plurality of images using the detected moving object area to generate a combined image.
9. A method comprising:
extracting a first difference between a plurality of images;
aligning by correcting a position of an image with reference to a predetermined subject within the plurality of images;
extracting a second difference between the plurality of images after the position of the image is corrected in the aligning; and
detecting a moving object area based on the extracted first difference and the extracted second difference.
10. The method according to claim 9 , wherein the detecting detects a portion that is common to the first difference and the second difference as the moving object area.
11. The method according to claim 9 , wherein the plurality of images are two images temporally adjacent to each other in terms of image capturing time.
12. The method according to claim 9 , wherein the aligning includes calculating a motion vector of the predetermined subject to perform alignment.
13. The method according to claim 9 , wherein the first difference and the second difference evaluate at least one of color and brightness.
14. The method according to claim 9 , further comprising combining the plurality of images using the detected moving object area to generate a combined image.
15. A non-transitory computer-readable storage medium storing a program for causing a computer to execute following steps comprising:
extracting a first difference between a plurality of images;
aligning by correcting a position of an image with reference to a predetermined subject within the plurality of images;
extracting a second difference between the plurality of images after the position of the image is corrected in the aligning; and
detecting a moving object area based on the extracted first difference and the extracted second difference.
16. The non-transitory computer-readable storage medium according to claim 15 , wherein the detecting detects a portion that is common to the first difference and the second difference as the moving object area.
17. The non-transitory computer-readable storage medium according to claim 15 , wherein the plurality of images are two images temporally adjacent to each other in terms of image capturing time.
18. The non-transitory computer-readable storage medium according to claim 15 , wherein the aligning includes calculating a motion vector of the predetermined subject to perform alignment.
19. The non-transitory computer-readable storage medium according to claim 15 , wherein the first difference and the second difference evaluate at least one of color and brightness.
20. The non-transitory computer-readable storage medium according to claim 15 , further comprising combining the plurality of images using the detected moving object area to generate a combined image.