Image processing device and image processing method
According to one embodiment, an image processing device includes a luminance acquiring unit and a local tone-mapping unit. The luminance acquiring unit acquires a luminance signal of a target pixel in an image by performing filter processing on an image signal. The luminance acquiring unit generates a luminance signal by blending a first luminance-filter result obtained by a first luminance filter and a second luminance-filter result obtained by a second luminance filter. The local tone-mapping unit performs local tone mapping of the luminance signal.
1. An image processing device comprising:
circuitry configured to
acquire a luminance signal of a target pixel in an image by performing filter processing on an image signal, the luminance signal being generated by blending a first luminance-filter result obtained by a first luminance filter and a second luminance-filter result obtained by a second luminance filter,
perform local tone mapping of the luminance signal, and
adjust a ratio of blending the first luminance-filter result and the second luminance-filter result in accordance with a result of evaluation of a contrast in a region of the image, including the target pixel.
2. The image processing device according to claim 1 , wherein the first luminance filter and the second luminance filter are different from each other in transfer characteristics with respect to a change of a luminance value.
3. The image processing device according to claim 1 , wherein the circuitry uses a result of binning processing on the image signal in an operation for evaluating the contrast.
4. An image processing device comprising:
circuitry configured to
acquire a luminance signal of a target pixel in an image by performing filter processing on an image signal, the luminance signal being generated by blending a first luminance-filter result obtained by a first luminance filter and a second luminance-filter result obtained by a second luminance filter,
perform local tone mapping of the luminance signal, and
blend a first mapping result and a second mapping result, the first mapping result being a conversion result of the luminance signal based on a relation represented as a first tone curve, the second mapping result being a conversion result of the luminance signal based on a relation represented as a second tone curve.
5. The image processing device according to claim 4 , the circuitry further configured to
perform processing of smoothing luminance distribution of the image on the luminance signal to generate a smoothed signal, and
adjust a ratio of blending the first mapping result and the second mapping result by referring to the smoothed signal.
6. The image processing device according to claim 5 , wherein the circuitry generates the smoothed signal by blending a first smoothing-filter result obtained by a first smoothing filter and a second smoothing-filter result obtained by a second smoothing filter.
7. The image processing device according to claim 6 , wherein the circuitry adjusts a ratio of blending the first smoothing-filter result and the second smoothing-filter result in accordance with a result of evaluation of a contrast in a region of the image, including the target pixel.
8. An image processing device comprising:
circuitry configured to
acquire a luminance signal of a target pixel in an image,
generate a smoothed signal by performing filter processing on the luminance signal to smooth luminance distribution of the image, the smoothed signal being generated by blending a first smoothing-filter result obtained by a first smoothing filter and a second smoothing-filter result obtained by a second smoothing filter, and
perform local tone mapping of the luminance signal by referring to the smoothed signal.
9. The image processing device according to claim 8 , wherein the circuitry adjusts a ratio of blending the first smoothing-filter result and the second smoothing-filter result in accordance with a result of evaluation of a contrast in a region of the image, including the target pixel.
10. The image processing device according to claim 9 , wherein the circuitry performs filter processing using a result of binning processing on the luminance signal, and performs an operation for evaluating the contrast by referring to data in a process of an operation in the binning processing.
11. The image processing device according to claim 8 , wherein a range in which luminance distribution is referred to in processing using the first smoothing filter is different from a range in which luminance distribution is referred to in processing using the second smoothing filter.
12. The image processing device according to claim 8 , wherein the circuitry performs filter processing using a result of binning processing on the luminance signal, and generates the smoothed signal for a binning range in the binning processing.
13. The image processing device according to claim 8 , wherein the circuitry blends a first mapping result and a second mapping result,
the first mapping result is a conversion result of the luminance signal based on a relation represented as a first tone curve, and
the second mapping result is a conversion result of the luminance signal based on a relation represented as a second tone curve.
14. The image processing device according to claim 13 , wherein the circuitry adjusts a ratio of blending the first mapping result and the second mapping result in accordance with a parameter based on the smoothed signal.
15. The image processing device according to claim 14 , wherein
the circuitry performs filter processing using a result of binning processing on the luminance signal, generates the smoothed signal for a binning range in the binning processing, and adjusts the ratio of blending in accordance with the parameter for the target pixel by weighted averaging of the smoothed signals in a plurality of binning ranges.
16. The image processing device according to claim 8 , wherein the circuitry generates the luminance signal by blending a first luminance-filter result obtained by a first luminance filter and a second luminance-filter result obtained by a second luminance filter.
17. The image processing device according to claim 16 , wherein the circuitry adjusts a ratio of blending the first luminance-filter result and the second luminance-filter result in accordance with a result of evaluation of a contrast in a region of the image, including the target pixel.
18. The image processing device according to claim 16 , wherein the first luminance filter and the second luminance filter are different from each other in transfer characteristics with respect to a change of a luminance value.
19. An image processing method comprising:
obtaining a first luminance-filter result for a target pixel in an image by performing filter processing using a first luminance filter for an image signal;
obtaining a second luminance-filter result for the target pixel by performing filter processing using a second luminance filter for an image signal;
generating a luminance signal of the target pixel by blending the first luminance-filter result and the second luminance-filter result;
obtaining a first smoothing-filter result by performing filter processing using a first smoothing filter for the luminance signal;
obtaining a second smoothing-filter result by performing filter processing using a second smoothing filter for the luminance signal;
generating a smoothed signal that is the luminance signal after being subjected to smoothing of luminance distribution of the image, by blending the first smoothing-filter result and the second smoothing-filter result; and
performing local tone mapping of the luminance signal by referring to the smoothed signal.