Image processing device and image processing method

An image processing method comprising:

• setting a three-dimensional object region by detecting a three-dimensional object, on a basis of a distance image that is to be generated on a basis of a stereo image and includes parallax-related values corresponding to parallaxes in respective pixels;
• setting, into the distance image, a first image region that is same as the three-dimensional object region in size and position, a second image region including a left end of the first image region and partly overlapping the first image region, and a third image region including a right end of the first image region and partly overlapping the first image region;
• calculating, in each of the first image region, the second image region, and the third image region, representative values of the parallax-related values including (i) a first representative value based on first parallax-related values corresponding to a first pixel column that includes pixels having a first horizontal coordinate in the distance image, and (ii) a second representative value based on second parallax-related values corresponding to a second pixel column that includes pixels having a second horizontal coordinate different from the first horizontal coordinate in the distance image;
• calculating a first approximate line in the first image region based on the representative values in the first image region, a second approximate line in the second image region based on the representative values in the second image region, and a third approximate line in the third image region based on the representative values in the third image region;
• estimating a continuous structure degree indicating a degree of likeliness of the three-dimensional object being a continuous structure, on a basis of a first slope value of the first approximate line of the first image region, a second slope value of the second approximate line of the second image region, and a third slope value of the third approximate line of the third image region;
• and
• determining whether the three-dimensional object detected is a vehicle, on a basis of the continuous structure degree.

An image processing device comprising

• circuitry configured to
• set a three-dimensional object region by detecting a three-dimensional object, on a basis of a distance image that is to be generated on a basis of a stereo image and includes parallax-related values corresponding to parallaxes in respective pixels,
• set, into the distance image, a first image region that is same as the three-dimensional object region in size and position, a second image region including a left end of the first image region and partly overlapping the first image region, and a third image region including a right end of the first image region and partly overlapping the first image region,
• calculate, in each of the first image region, the second image region, and the third image region, representative values of the parallax-related values including (i) a first representative value based on first parallax-related values corresponding to a first pixel column that includes pixels having a first horizontal coordinate in the distance image, and (ii) a second representative value based on second parallax-related values corresponding to a second pixel column that includes pixels having a second horizontal coordinate different from the first horizontal coordinate in the distance image,
• calculate a first approximate line in the first image region based on the representative values in the first image region, a second approximate line in the second image region based on the representative values in the second image region, and a third approximate line in the third image region based on the representative values in the third image region,
• estimate a continuous structure degree indicating a degree of likeliness of the three-dimensional object being a continuous structure, on a basis of a first slope value of the first approximate line of the first image region, a second slope value of the second approximate line of the second image region, and a third slope value of the third approximate line of the third image region, and
• determine whether the three-dimensional object detected by the detector is a vehicle, on a basis of the continuous structure degree.