Image processing device, image processing method, and program

1. An image processing device comprising:

circuitry configured to

calculate a matching degree between a pixel value of a target pixel in a standard image of a current frame and a pixel value of a corresponding pixel in a reference image of the current frame; and

estimate a disparity between the standard image and the reference image based on a result obtained by calculating the matching degree, wherein

the circuitry calculates the matching degree using a disparity estimated for the standard image and the reference image of a previous frame,

the circuitry calculates a temporal evaluation value used to evaluate a temporal variation in a disparity based on a difference between the disparity for the previous frame and the disparity estimated for the standard image and the reference image of the current frame, and

the circuitry calculates the matching degree using the temporal evaluation value.

2. The image processing device according to claim 1 , wherein the circuitry applies a weight to the temporal evaluation value depending on a movement in the standard image or the reference image.

3. The image processing device according to claim 2 , wherein the circuitry sets the weight to be applied to the temporal evaluation value to be larger as a movement in the standard image or the reference image becomes smaller.

4. The image processing device according to claim 3 , wherein the circuitry calculates the matching degree, using a pixel value of a pixel of a target region including the target pixel in the standard image of the current frame and a pixel value of a pixel of a corresponding region including the corresponding pixel in the reference image of the current frame.

5. The image processing device according to claim 1 , wherein

the circuitry calculates a spatial evaluation value used to evaluate a spatial variation in a disparity based on a difference between a disparity estimated for a neighboring pixel located near the target pixel and a disparity estimated for the target pixel, and

the circuitry calculates the matching degree using the temporal evaluation value and the spatial evaluation value.

6. The image processing device according to claim 5 , wherein the circuitry applies a weight to the spatial evaluation value depending on a pixel value of the target pixel.

7. The image processing device according to claim 1 , wherein

the circuitry converts luminance to a disparity based on a luminance value and a disparity for the previous frame, the luminance being a luminance value of a textureless region in the standard image of the current frame,

the circuitry calculates a luminance-disparity evaluation value used to evaluate a disparity converted from luminance based on a difference between the disparity converted from luminance of the standard image and the disparity estimated for the standard image of the current frame, and

the circuitry calculates the matching degree using the temporal evaluation value and the luminance-disparity evaluation value.

8. The image processing device according to claim 7 , wherein the circuitry applies a weight to the luminance-disparity evaluation value depending on reliability of luminance-to-disparity conversion performed by the circuitry.

9. The image processing device according to claim 8 , wherein the circuitry sets the weight to be applied to the luminance-disparity evaluation value to be larger as the reliability of luminance-to-disparity conversion performed by the circuitry becomes higher.

10. An image processing method comprising:

calculating, using circuitry, a matching degree between a pixel value of a target pixel in a standard image of a current frame and a pixel value of a corresponding pixel in a reference image of the current frame; and

estimating a disparity between the standard image and the reference image based on a result obtained by calculating the matching degree, wherein

the matching degree is calculated, in the calculating of the matching degree calculating, using a disparity estimated for the standard image and the reference image of a previous frame, and

the method further comprising calculating a temporal evaluation value used to evaluate a temporal variation in a disparity based on a difference between the disparity for the previous frame and the disparity estimated for the standard image and the reference image of the current frame, and calculating the matching degree using the temporal evaluation value.

11. A non-transitory computer readable medium including executable instructions, which when executed by a computer cause the computer to execute an image processing method, the method comprising:

calculating a matching degree between a pixel value of a target pixel in a standard image of a current frame and a pixel value of a corresponding pixel in a reference image of a current frame; and

estimating a disparity between the standard image and the reference image based on a result obtained by calculating the matching degree, wherein

the matching degree is calculated, in the calculating of the matching degree calculating, using a disparity estimated for the standard image and the reference image of a previous frame, and

the method further comprising calculating a temporal evaluation value used to evaluate a temporal variation in a disparity based on a difference between the disparity for the previous frame and the disparity estimated for the standard image and the reference image of the current frame, and calculating the matching degree using the temporal evaluation value.