Image processing apparatus, optical apparatus, image processing method, and non-transitory computer-readable storage medium
An image processing apparatus includes a processor that sharpens an input image on the basis a difference between a filter and a low pass filter, which are generated using of information regarding a point spread function of an optical system corresponding to an image pickup condition of the optical system, or a difference between an image obtained by applying the filter to an input image generated by imaging through the optical system and an image obtained by applying the low pass filter to the input image.
1. An image processing apparatus comprising:
a processor that sharpens an input image on the basis of a difference between a filter and a low pass filter, which are generated using information regarding a point spread function of an optical system corresponding to an image pickup condition of the optical system, or a difference between an image obtained by applying the filter to an input image generated by imaging through the optical system and an image obtained by applying the low pass filter to the input image.
2. An image processing apparatus according to claim 1 , wherein the processor generates a sharpening filter on the basis of a difference between the filter and the low pass filter, and an ideal point image, and sharpens the input image by applying the sharpening filter to the input image.
3. The image processing apparatus according to claim 2 , wherein the processor sharpens the input image by convoluting the sharpening filter into the input image.
4. The image processing apparatus according to claim 2 , wherein the processor adjusts the sharpening filter using an adjustment coefficient corresponding to a position in the input image.
5. The image processing apparatus according to claim 1 , wherein the processor generates a correction component by convoluting a difference between the filter and the low pass filter into the input image, and sharpens the input image by applying the correction component to the input image.
6. The image processing apparatus according to claim 5 , wherein the processor sharpens the input image by adding the correction component to the input image.
7. The image processing apparatus according to claim 1 , wherein the processor generates a correction component on the basis of a difference between an image obtained by applying the filter to the input image and an image obtained by applying the low pass filter to the input image, and sharpens the input image by applying the correction component to the input image.
8. The image processing apparatus according to claim 7 , wherein the processor sharpens the input image by adding the correction component to the input image.
9. The image processing apparatus according to claim 1 , wherein the low pass filter is rotationally symmetrical.
10. The image processing apparatus according to claim 1 , wherein the low pass filter has a number of taps less than a number of taps of the filter.
11. The image processing apparatus according to claim 1 , wherein the processor obtains information regarding the point spread function on the basis of the image pickup condition of the optical system.
12. The image processing apparatus according to claim 1 , wherein the image pickup condition is at least one of an image height, a focal length, a F-number and a photographing distance.
13. The image processing apparatus according to claim 1 , wherein the low pass filter has characteristics constant to the image pickup condition.
14. The image processing apparatus according to claim 1 , wherein the low pass filter has characteristics different for each image pickup condition.
15. An optical apparatus comprising:
an image pickup element that images an object image formed by an optical system; and
an image processing apparatus including a processor that sharpens an input image on the basis of a difference between a filter and a low pass filter, which are generated using information regarding a point spread function of an optical system corresponding to an image pickup condition of the optical system, or a difference between an image obtained by applying the filter to an input image generated by imaging using the image pickup element and an image obtained by applying the low pass filter to the input image.
16. An image processing method comprising:
the step of sharpening an input image on the basis of a difference between a filter and a low pass filter, which are generated using information regarding a point spread function of an optical system corresponding to an image pickup condition of the optical system, or a difference between an image obtained by applying the filter to an input image generated by imaging through the optical system and an image obtained by applying the low pass filter to the input image.
17. A non-transitory computer-readable storage medium configured to store a computer program that enables a computer to execute an image processing method, wherein the image processing method comprises:
the step of sharpening an input image on the basis of a difference between a filter and a low pass filter, which are generated using information regarding a point spread function of an optical system corresponding to an image pickup condition of the optical system, or a difference between an image obtained by applying the filter to an input image generated by imaging through the optical system and an image obtained by applying the low pass filter to the input image.