Distance measuring apparatus and method

1 . A distance measuring apparatus comprising:

an imaging device that captures images in which a subject is captured; and

a processing device configured to acquire the images from the imaging device and process the images, input two or more images including a first image obtained by photographing the subject from a first viewpoint and a second image obtained by photographing the subject from a second viewpoint different from the first viewpoint among the images, and generate two or more images as characteristic matching images in which a characteristic of the first image and a characteristic of the second image are matched,

calculate a distance to the subject by calculating a parallax based on the two or more images as the characteristic matching images, and

generate the characteristic matching images by projecting a pixel of interest in at least one of the first image and the second image to a corresponding pixel position in the other image,

wherein the processing device is configured to perform image processing of converting a one-point perspective coordinate system of the characteristic matching images into a cylindrical coordinate system for distance calculation, and

wherein the processing device applies a filter having a constant cutoff frequency to the characteristic matching images.

2 . The distance measuring apparatus according to claim 1 , wherein

the processing device generates the characteristic matching images by projecting a pixel of interest in the first image to a corresponding pixel position in the second image.

3 . The distance measuring apparatus according to claim 1 , wherein

the processing device generates a first characteristic matching image by projecting a pixel of interest in the first image to a corresponding pixel position in the second image;

generates a second characteristic matching image by projecting a pixel of interest in the second image to a corresponding pixel position in the first image; and

sets the first characteristic matching image and the second characteristic matching image as the characteristic matching images.

4 . The distance measuring apparatus according to claim 1 , wherein

the characteristic is the number of effective pixels as the number of pixels that can be used for distance measurement relating to a pixel number distribution of a same mapped image in the image.

5 . The distance measuring apparatus according to claim 1 , wherein

the processing device determines the corresponding pixel position of the pixel of interest in the projection based on an image height characteristic of an optical system that captures the first image of the imaging device and an image height characteristic of an optical system that captures the second image.

6 . The distance measuring apparatus according to claim 1 , wherein

the imaging device includes a single image sensor and an imaging optical system that images light from the subject on the image sensor, and

the imaging optical system includes a first optical system that projects a first mapped image corresponding to the first image to the image sensor, and a second optical system that projects a second mapped image corresponding to the second image to the image sensor.

7 . The distance measuring apparatus according to claim 6 , wherein

the imaging optical system includes a plurality of hyperboloid mirrors as elements constituting the first optical system and the second optical system.

8 . The distance measuring apparatus according to claim 6 , wherein

the first image and the second image in the image are arranged in a concentric ring shape.

9 . The distance measuring apparatus according to claim 1 , wherein

the imaging device includes:

a first lens and a first image sensor as a first optical system that captures the first image; and

a second lens and a second image sensor as a second optical system that captures the second image, and

the first optical system and the second optical system are arranged to face back or opposite to each other on a same axis.

10 . The distance measuring apparatus according to claim 1 , wherein

the imaging device includes:

a first lens and a first image sensor as a first optical system that captures the first image; and

a second lens and a second image sensor as a second optical system that captures the second image, and

the first optical system and the second optical system have optical axes arranged in parallel in a same direction.

11 . The distance measuring apparatus according to claim 10 , wherein

the processing device performs image processing of converting a coordinate system of the characteristic matching images into a coordinate system for distance calculation, and

the processing device converts the first image and the second image each having a concentric ring shape in the characteristic matching images into rectangular panoramic images, inverts one of the obtained first panoramic image and second panoramic image so as to match directions of mapped images of the subject, and sets the first panoramic image and the second panoramic image as two images for distance calculation.

12 . A distance measuring method in a distance measuring apparatus, the distance measuring apparatus including: an imaging device that captures images in which a subject is captured; and

a processing device that acquires the image from the imaging device and processes the image, the distance measuring method comprising:

a characteristic matching image generation step of, by the processing device, inputting two or more images including a first image obtained by photographing the subject from a first viewpoint and a second image obtained by photographing the subject from a second viewpoint different from the first viewpoint among the images, and generating two or more images as characteristic matching images in which a characteristic of the first image and a characteristic of the second image are matched; and

a distance measurement step of, by the processing device, calculating a distance to the subject by calculating a parallax based on the two or more images as the characteristic matching images, and

wherein the characteristic matching image generation step generates the characteristic matching images by projecting a pixel of interest in at least one of the first image and the second image to a corresponding pixel position in the other image,

wherein the processing device is configured to perform image processing of converting a one-point perspective coordinate system of the characteristic matching images into a cylindrical coordinate system for distance calculation, and

wherein the processing device applies a filter having a constant cutoff frequency to the characteristic matching images.

13 . A distance measuring apparatus comprising:

an imaging device that captures images in which a subject is captured; and

a processing device configured to acquire the images from the imaging device and process the images, input two or more images including a first image obtained by photographing the subject from a first viewpoint and a second image obtained by photographing the subject from a second viewpoint different from the first viewpoint among the images, and generate two or more images as characteristic matching images in which a characteristic of the first image and a characteristic of the second image are matched,

calculate a distance to the subject by calculating a parallax based on the two or more images as the characteristic matching images, and

generate the characteristic matching images by projecting a pixel of interest in at least one of the first image and the second image to a corresponding pixel position in the other image, wherein the processing device is configured to perform image processing of converting a one-point perspective coordinate system of the characteristic matching images into a cylindrical coordinate system for distance calculation, and

wherein the imaging device includes:

a first lens and a first image sensor as a first optical system that captures the first image; and

a second lens and a second image sensor as a second optical system that captures the second image, and

the first optical system and the second optical system are arranged to face back or opposite to each other on a same axis.