Electronic device for sharpening image and operation method thereof
Provided are an electronic device for sharpening an image and an operation method thereof. A method, performed by the electronic device, of sharpening an image includes: obtaining an image generated by a camera of the electronic device; obtaining a first sharpening kernel for enhancing sharpness of the image, wherein the first sharpening kernel is data including a plurality of weights to be applied to pixels in the image, the data being of a lower resolution than the image; determining coordinates corresponding to some weights indicating representative values of the first sharpening kernel from among the plurality of weights in the first sharpening kernel; generating a second sharpening kernel by selecting the weights corresponding to the determined coordinates; and obtaining a sharpened image by applying the second sharpening kernel to the image.
1. A method, performed by an electronic device, the method comprising:
obtaining an image by a camera of the electronic device;
obtaining a first sharpening kernel for enhancing sharpness of the image, wherein the first sharpening kernel is data including a plurality of weights to be applied to pixels in the image, and the data is of a lower resolution than the image;
determining coordinates corresponding to first weights indicating representative values of the first sharpening kernel from among the plurality of weights in the first sharpening kernel, wherein the representative values are values indicating feature points of a shape of the first sharpening kernel;
generating a second sharpening kernel by selecting the first weights corresponding to the determined coordinates; and
obtaining a sharpened image by applying the second sharpening kernel to the image.
2. The method of claim 1 , wherein the obtaining the first sharpening kernel comprises:
obtaining, by using the camera of the electronic device, a reference image;
calculating a point spread function based on the reference image; and
obtaining the first sharpening kernel based on the point spread function.
3. The method of claim 1 , wherein the determining the coordinates corresponding to the first weights indicating the representative values of the first sharpening kernel comprises determining as zero point coordinates of a weight, from among the plurality of weights, corresponding to a center point of the first sharpening kernel.
4. The method of claim 1 , further comprising obtaining an augmented first sharpening kernel including new weights by performing interpolation between adjacent weights among the plurality of weights in the first sharpening kernel.
5. The method of claim 4 , wherein the determining the coordinates corresponding to the first weights comprises determining the coordinates corresponding to the first weights from among the new weights in the augmented first sharpening kernel.
6. The method of claim 5 , further comprising:
obtaining a third sharpening kernel by selecting second weights in the augmented first sharpening kernel; and
obtaining a fourth sharpening kernel by selecting third weights from the augmented first sharpening kernel at certain intervals,
wherein the determining the coordinates corresponding to the first weights indicating the representative values of the first sharpening kernel comprises determining the coordinates corresponding to the first weights indicating the representative values of the first sharpening kernel, based on a comparison of a result of applying the third sharpening kernel to the image with a result of applying the fourth sharpening kernel to the image.
7. The method of claim 6 , wherein a number of weights in the fourth sharpening kernel is greater than a number of weights in the third sharpening kernel.
8. The method of claim 5 , further comprising, based on one or more of the new weights being included in the first weights indicating the representative values of the first sharpening kernel, generating pixels corresponding to the one or more of the new weights by performing interpolation on the pixels in the image.
9. The method of claim 1 , wherein the determining the coordinates corresponding to the first weights indicating the representative values of the first sharpening kernel comprises:
applying a high pass filter to the first sharpening kernel; and
determining, based on absolute values of the first sharpening kernel and absolute values of the first sharpening kernel to which the high pass filter is applied, the coordinates corresponding to the first weights indicating the representative values of the first sharpening kernel.
10. The method of claim 9 , wherein the first weights in the second sharpening kernel are weights at positions symmetric with respect to a center point of the second sharpening kernel, and
a maximum value among the first weights in the second sharpening kernel is located at the center point of the second sharpening kernel.
11. An electronic device comprising:
a communication interface;
a camera;
a memory storing one or more instructions; and
at least one processor configured to execute the one or more instructions stored in the memory to:
obtain an image generated by the camera,
obtain a first sharpening kernel for enhancing sharpness of the image, wherein the first sharpening kernel is data including a plurality of weights to be applied to pixels in the image, and the data is of a lower resolution than the image,
determine coordinates corresponding to first weights indicating representative values of the first sharpening kernel from among the plurality of weights in the first sharpening kernel, wherein the representative values are values indicating feature points of a shape of the first sharpening kernel,
generate a second sharpening kernel by selecting the first weights corresponding to the determined coordinates, and
obtain a sharpened image by applying the second sharpening kernel to the image.
12. The electronic device of claim 11 , wherein the at least one processor is further configured to execute the one or more instructions to:
obtain a reference image by using the camera;
calculate a point spread function based on the reference image; and
obtain the first sharpening kernel based on the point spread function.
13. The electronic device of claim 11 , wherein the at least one processor is further configured to execute the one or more instructions to determine as zero point coordinates of a weight, from among the plurality of weights, corresponding to a center point of the first sharpening kernel.
14. The electronic device of claim 11 , wherein the at least one processor is further configured to execute the one or more instructions to obtain an augmented first sharpening kernel including new weights by performing interpolation between adjacent weights among the plurality of weights in the first sharpening kernel.
15. The electronic device of claim 14 , wherein the at least one processor is further configured to execute the one or more instructions to determine the coordinates corresponding to the first weights from among the new weights in the augmented first sharpening kernel.
16. The electronic device of claim 15 , wherein the at least one processor is further configured to execute the one or more instructions to:
obtain a third sharpening kernel by selecting second weights in the augmented first sharpening kernel;
obtain a fourth sharpening kernel by selecting third weights from the augmented first sharpening kernel at certain intervals; and
determine the coordinates corresponding to the first weights indicating the representative values of the first sharpening kernel, based on a comparison of a result of applying the third sharpening kernel to the image with a result of applying the fourth sharpening kernel to the image.
17. The electronic device of claim 15 , wherein the at least one processor is further configured to execute the one or more instructions to, based on one or more of the new weights being included in the first weights indicating the representative values of the first sharpening kernel, generate pixels corresponding to the one or more of the new weights by performing interpolation on the pixels in the image.
18. The electronic device of claim 11 , wherein the at least one processor is further configured to execute the one or more instructions to:
apply a high pass filter to the first sharpening kernel; and
determine, based on absolute values of the first sharpening kernel and absolute values of the first sharpening kernel to which the high pass filter is applied, the coordinates corresponding to the first weights indicating the representative values of the first sharpening kernel.
19. The electronic device of claim 18 , wherein the first weights in the second sharpening kernel are weights at positions symmetric with respect to a center point of the second sharpening kernel, and
a maximum value among the first weights in the second sharpening kernel is located at the center point of the second sharpening kernel.
20. A non-transitory computer-readable recording medium having recorded thereon a program that is executable by at least one process to perform the method of claim 1 .