Distance measurement apparatus, distance measurement method, and non-transitory computer-readable storage medium

A method, implemented by a processor circuitry, for distance measurement, the method comprising:

• executing, by the processor circuitry, a measurement process that includes generating an image having a plurality of pixels, each of the plurality of pixels corresponding to a range point and representing a distance value obtained by measuring a distance to the range point based on reflected light of a pulsed laser beam for two-dimensional scanning;
• executing, by the processor circuitry, a first process that includes extracting, from the image, a first area having a plurality of range points at which the distance value is less than or equal to a first threshold, wherein a difference between each pair of the plurality of range points included in the first area is less than or equal to a second threshold, and the first area has an area size less than or equal to a threshold size;
• and
• executing, by the processor circuitry, a second process that includes
• extracting an area group which has a plurality of the first areas, wherein a distance, in terms of two-dimensional coordinates in the image, between each of the plurality of the first areas and another of the plurality of the first areas is less than or equal to a third threshold, and a difference of the distance value between each pair of the plurality of the first areas is greater than a fourth threshold, and
• determining the area group as a noise area when the number of the plurality of the first areas included in the area group is greater than or equal to a certain number.

A non-transitory computer-readable storage medium storing a program that causes processor circuitry to execute a distance measurement process, the distance measurement process comprising:

• executing a measurement process that includes generating an image having a plurality of pixels, each of the plurality of pixels corresponding to a range point and representing a distance value obtained by measuring a distance to the range point based on reflected light of a pulsed laser beam for two-dimensional scanning;
• executing a first process that includes extracting, from the image, a first area having a plurality of range points at which the distance value is less than or equal to a first threshold, wherein a difference between each pair of the plurality of range points included in the first area is less than or equal to a second threshold, and the first area has an area size less than or equal to a threshold size;
• and
• executing a second process that includes
• extracting an area group which has a plurality of the first areas, wherein a distance, in terms of two-dimensional coordinates in the image, between each of the plurality of the first areas and another of the plurality of the first areas is less than or equal to a third threshold, and a difference of the distance value between each pair of the plurality of the first areas is greater than a fourth threshold, and
• determining the area group as a noise area when the number of the plurality of the first areas included in the area group is greater than or equal to a certain number.