Image-processing apparatus, image-processing method, and storage medium storing image-processing program

1. An image-processing apparatus comprising:

an image processor comprising circuitry or a hardware processor that operates under control of a stored program, the image processor being configured to execute processes comprising:

a saliency-map calculating process that calculates saliency maps based on at least one type of feature quantity obtained from an input image;

a salient-region-identifying process that identifies a salient region by using the saliency maps;

a salient-region-score-calculating process that calculates a score of the salient region by comparing a distribution of values of the saliency map in the salient region and a distribution of values of the saliency map in a region other than the salient region; and

a saliency-evaluating process that evaluates the saliency of the salient region based on the score,

wherein the salient-region-score-calculating process calculates the score based on a difference between a weighted sum of an average value and a maximum value of the saliency map in the salient region and an average value of the saliency map in the region other than the salient region.

2. An image-processing apparatus comprising:

an image processor comprising circuitry or a hardware processor that operates under control of a stored program, the image processor being configured to execute processes comprising:

a saliency-map calculating process that calculates saliency maps based on at least one type of feature quantity obtained from an input image;

a salient-region-identifying process that identifies a salient region by using the saliency maps;

a salient-region-score-calculating process that calculates a score of the salient region by comparing a distribution of values of the saliency map in the salient region and a distribution of values of the saliency map in a region other than the salient region; and

a saliency-evaluating process that evaluates the saliency of the salient region based on the score,

wherein the salient-region-score-calculating process normalizes the score by using variability of the distribution of the values of the saliency map in the region other than the salient region.

3. The image-processing apparatus according to claim 2 , wherein the salient-region-score-calculating process uses, as the variability of the distribution of the values of the saliency map in the region other than the salient region, a standard deviation of the values of the saliency map.

4. An image-processing apparatus comprising:

an image processor comprising circuitry or a hardware processor that operates under control of a stored program, the image processor being configured to execute processes comprising:

a saliency-map calculating process that calculates saliency maps based on of at least one type of feature quantity obtained from an input image;

a salient-region-identifying process that identifies a salient region by using the saliency maps;

a salient-region-score-calculating process that calculates a score by using a number of local maximum points in the saliency map in the region other than the salient region; and

a saliency-evaluating process that evaluates the saliency of the salient region based on the score.

5. A non-transitory computer-readable storage medium storing an image-processing program that causes a computer to execute processes comprising:

calculating saliency maps based on a basis of at least one type of feature quantity obtained from an input image;

identifying a salient region by using the saliency maps;

calculating a score of the salient region by comparing a distribution of values of the saliency map in the salient region and a distribution of values of the saliency map in a region other than the salient region, the score being calculated based on a difference between a weighted sum of an average value and a maximum value of the saliency map in the salient region and an average value of the saliency map in the region other than the salient region; and

evaluating the saliency of the salient region based on the score.

6. A non-transitory computer-readable storage medium storing an image-processing program that causes a computer to execute processes comprising:

calculating saliency maps based on at least one type of feature quantity obtained from an input image;

identifying a salient region by using the saliency maps;

calculating a score by using a number of local maximum points in the saliency map in a region other than the salient region; and

evaluating the saliency of the salient region based on the score.

7. A non-transitory computer-readable storage medium storing an image-processing program that causes a computer to execute processes comprising:

calculating saliency maps based on at least one type of feature quantity obtained from an input image;

identifying a salient region by using the saliency maps;

calculating a score of the salient region by comparing a distribution of values of the saliency map in the salient region and a distribution of values of the saliency map in a region other than the salient region, and normalizing the score by using variability of the distribution of values of the saliency map in the region other than the salient region; and

evaluating the saliency of the salient region based on the score.