Image processing apparatus, image adjusting apparatus, image processing method and computer readable medium

1. An image processing apparatus comprising:

a decomposing section that decomposes a luminance component of a given original image into a plurality of band images in respective bands;

a band intensity calculating section that calculates band intensities of the respective band images; and

a determining section that determines band selection information indicating an emphasis band and band emphasis information to be used for controlling a degree of image emphasis based on the band intensities of the respective bands;

wherein the determining section determines band selection information based on differences between the band intensities of the respective bands and set band reference values and determines band emphasis information according to a difference between the band intensity and the band reference value of the band indicated by the band selection information.

2. The image processing apparatus according to claim 1 , wherein the decomposing section sets a plurality of bands that range from a low-frequency band to a high-frequency band and include at least one low-frequency-side band not including zero frequency.

3. The image processing apparatus according to claim 1 , wherein the band intensity calculating section calculates a band intensity of each of the band images based on an integration value of pixel values thereof.

4. The image processing apparatus according to claim 1 , wherein the determining section determines band selection information and band emphasis information based on differences between the band intensities of the respective bands and set band reference values.

5. The image processing apparatus according to claim 1 , further comprising:

a band region image generating section that generates a band region image indicating large-pixel-value regions in each of the band images; and

an area parameter calculating section that calculates an area parameter representing the total area of the large-pixel-value regions based on the band region image of each of the band images,

wherein the band intensity calculating section calculates a band intensity of each of the band images using the band image and band region image thereof; and

the determining section determines band selection information and band emphasis information based on the calculated band intensities and area parameters.

6. The image processing apparatus according to claim 5 , wherein the band region image generating section generates a band region image of each of the band images by binarizing the band image.

7. The image processing apparatus according to claim 5 , wherein the determining section determines band selection information and band emphasis information based on one or both of differences between the band intensities of the respective bands and set band reference values and the area parameters of the respective bands.

8. The image processing apparatus according to claim 5 , wherein the determining section determines band selection information based on one or both of differences between the band intensities of the respective bands and set band reference values and the area parameters of the respective bands, and determines band emphasis information according to a difference between the band intensity and the band reference value of the band indicated by the band selection information.

9. An image adjusting apparatus comprising:

an adjusting section that adjusts color characteristic of a given original image; a converting section that converts the color-characteristic-adjusted original image into a luminance/chromaticity image;

a band image generating section that generates a band image of the band indicated by the band selection information determined by the image processing apparatus according to claim 1 based on a luminance image of the luminance/chromaticity image; and

an emphasizing section that produces a band-emphasized image according to the band emphasis information determined by the image processing apparatus according to claim 1 using the luminance image and the band image.

10. An image adjusting apparatus comprising:

a luminance image generating section that generates a luminance image from a given original image;

a band image generating section that generates a band image of the band indicated by the band selection information determined by the image processing apparatus according to claim 1 based on the luminance image; and

an emphasizing section that produces a band-emphasized image according to the band emphasis information determined by the image processing apparatus according to claim 1 using the luminance image and the band image;

an adjusting section that adjusts color characteristic of the given original image; and

a converting section that converts the color-characteristic-adjusted original image into a luminance/chromaticity image.

11. An image processing method comprising:

decomposing a luminance component of a given original image into a plurality of band images in respective bands;

calculating band intensities of the respective band images; and determining band selection information indicating an emphasis band and band emphasis information to be used for controlling a degree of image emphasis based on the band intensities of the respective bands;

determining band selection information based on differences between the band intensities of the respective bands and set band reference values; and

determining band emphasis information according to a difference between the band intensity and the band reference value of the band indicated by the band selection information.

12. A non-transitory computer readable medium storing a program causing a computer to execute a process for image processing, the process comprising:

decomposing a luminance component of a given original image into a plurality of band images in respective bands;

calculating band intensities of the respective band images; and

determining band selection information indicating an emphasis band and band emphasis information to be used for controlling a degree of image emphasis based on the band intensities of the respective bands;

determining band selection information based on differences between the band intensities of the respective bands and set band reference values; and

determining band emphasis information according to a difference between the band intensity and the band reference value of the band indicated by the band selection information.