Image processor, image processing method, and program
View Patent ↗An image processor of the disclosure includes: an image sensor that captures an image of an underwater measurement target; a first laser light source that emits first laser light underwater; a second laser light source that emits second laser light underwater from a position that differs from the first laser light source; and a correction data generation unit that generates, on the basis of first information acquired by causing the image sensor to capture images of the first and second laser light beams at a first water depth and second information acquired by causing the image sensor to capture images of the first and second laser light beams at a second water depth which is a water depth at which the image sensor captures an image of the measurement target, correction data used to correct distortion in a captured image captured by the image sensor at the second water depth.
1 . An image processor comprising:
an image sensor that captures an image of an underwater measurement target;
a first laser light source that emits first laser light underwater;
a second laser light source that emits second laser light underwater from a position that differs from the first laser light source; and
a correction data generation unit that generates, on a basis of first information acquired by causing the image sensor to capture images of the first laser light and the second laser light at a first water depth and second information acquired by causing the image sensor to capture images of the first laser light and the second laser light at a second water depth which is a water depth at which the image sensor captures an image of the measurement target, correction data used to correct distortion in a captured image captured by the image sensor at the second water depth.
2 . The image processor according to claim 1 , further comprising a parameter correction unit that corrects, on a basis of the correction data generated by the correction data generation unit, a calibration parameter used to correct distortion in the captured image captured by the image sensor.
3 . The image processor according to claim 2 , further comprising a distortion correction unit that corrects, on a basis of the calibration parameter corrected by the parameter correction unit, distortion in a captured image of the measurement target, the captured image being captured by the image sensor.
4 . The image processor according to claim 3 , further comprising a depth image generation unit that generates a depth image on a basis of the captured image of the measurement target, the captured image being corrected by the distortion correction unit.
5 . The image processor according to claim 4 , further comprising a distance estimation unit that estimates a distance to the measurement target on a basis of captured images of the first laser light and the second laser light, the captured images being captured by the image sensor at the second water depth, wherein
the depth image generation unit sets, on a basis of the distance estimated by the distance estimation unit, a range of search for the measurement target for generating the depth image.
6 . The image processor according to claim 1 , wherein
the correction data generation unit acquires, as the first information, information regarding a first intersection point of the first laser light and the second laser light of which the images are captured by the image sensor at the first water depth,
the correction data generation unit acquires, as the second information, information regarding a second intersection point corresponding to the first intersection point of the first laser light and the second laser light of which the images are captured by the image sensor at the second water depth, and
the correction data generation unit generates the correction data on a basis of information regarding an amount of movement between the first intersection point and the second intersection point on the captured images captured by the image sensor.
7 . The image processor according to claim 6 , further comprising:
a first scan mechanism that scans the first laser light emitted from the first laser light source; and
a second scan mechanism that scans the second laser light emitted from the second laser light source, wherein
the correction data generation unit controls the scanning performed by the first scan mechanism and the second scan mechanism to acquire the information regarding the first intersection point and the information regarding the second intersection point in each of all pixels on the captured images captured by the image sensor.
8 . The image processor according to claim 7 , further comprising a correction data holding unit that holds pieces of information of the information regarding the first intersection point and the information regarding the second intersection point in association, respectively, with information regarding a first angle of scanning performed by the first scan mechanism and information regarding a second angle of scanning performed by the second scan mechanism.
9 . The image processor according to claim 8 , wherein the correction data holding unit holds the correction data in association with depth information regarding the second water depth.
10 . The image processor according to claim 1 , further comprising a pattern projector that irradiates the measurement target with a predetermined pattern.
11 . The image processor according to claim 1 , further comprising a plurality of pattern projectors that irradiates the measurement target with respective predetermined patterns with wavelength ranges that differ from each other.
12 . The image processor according to claim 11 , wherein the correction data generation unit presumes underwater turbidity on a basis of the captured images of the first laser light and the second laser light, the captured images being captured by the image sensor at the second water depth, and selects, on a basis of the presumed underwater turbidity, one of the plurality of pattern projectors as a pattern projector that irradiates the predetermined pattern.
13 . An image processing method comprising:
causing an image sensor to capture an image of an underwater measurement target;
emitting first laser light underwater;
emitting second laser light underwater from a position that differs from the first laser light source; and
generating, on a basis of first information acquired by causing the image sensor to capture images of the first laser light and the second laser light at a first water depth and second information acquired by causing the image sensor to capture images of the first laser light and the second laser light at a second water depth which is a water depth at which the image sensor captures an image of the measurement target, correction data used to correct distortion in a captured image captured by the image sensor at the second water depth.
14 . A non-transitory memory storing a program that, when executed by a computer, causes the computer to:
emit first laser light underwater;
emit second laser light underwater from a position that differs from the first laser light source; and
generate, on a basis of first information acquired by causing an image sensor to capture images of the first laser light and the second laser light at a first water depth and second information acquired by causing the image sensor to capture images of the first laser light and the second laser light at a second water depth which is a water depth at which the image sensor captures an image of a measurement target, correction data used to correct distortion in a captured image captured by the image sensor at the second water depth.