Surroundings monitoring apparatus and surroundings monitoring method for reducing distortion caused by camera position displacement

A surroundings monitoring method which generates a surrounding image using an image captured by a camera, the surroundings monitoring method comprising:

• a position displacement information obtainment step of obtaining position displacement information which is information regarding a displacement in a position of the camera;
• a coordinate transformation parameter obtainment step of obtaining, based on the position displacement information obtained by the position displacement information obtainment step, a coordinate transformation parameter for correcting a distortion in the surrounding image caused by the displacement in the position, the coordinate transformation parameter defining a function for transforming two-dimensional coordinates of one pixel into two-dimensional coordinates of another pixel;
• an image synthesis parameter obtainment step of obtaining at least one reference image synthesis parameter which is used for generating the surrounding image using the captured image, the at least one reference image synthesis parameter including information of image coordinates indicating, on the captured image, a pixel position corresponding to each pixel in the surrounding image, and the image coordinates being two-dimensional coordinates;
• a coordinate transformation step of performing coordinate transformation on the two-dimensional image coordinates included in the at least one reference image synthesis parameter obtained by the image synthesis parameter obtainment step, using the coordinate transformation parameter obtained by the coordinate transformation parameter obtainment step, and of outputting the image coordinates as a transformed image synthesis parameter indicating transformed two-dimensional image coordinates;
• and
• an image synthesis step of generating the surrounding image by applying the transformed image synthesis parameter to the captured image, and of outputting the generated surrounding image,
• wherein the image synthesis step reads, from among pixels included in the captured image, an image of a pixel located in the transformed two-dimensional image coordinates indicated by the transformed image synthesis parameter, and outputs the read image as an image of a pixel located in the surrounding image and corresponding to the pixel located in the transformed two-dimensional image coordinates.

A non-transitory computer-readable recording medium storing a program for generating a surrounding image using an image captured by a camera, the program causing a computer to execute steps comprising:

• a position displacement information obtainment step of obtaining position displacement information which is information regarding a displacement in a position of the camera;
• a coordinate transformation parameter obtainment step of obtaining, based on the position displacement information obtained by the position displacement information obtainment step, a coordinate transformation parameter for correcting a distortion in the surrounding image caused by the displacement in the position, the coordinate transformation parameter defining a function for transforming two-dimensional coordinates of one pixel into two-dimensional coordinates of another pixel;
• an image synthesis parameter obtainment step of obtaining at least one reference image synthesis parameter which is used for generating the surrounding image using the captured image, the at least one reference image synthesis parameter including information of image coordinates indicating, on the captured image, a pixel position corresponding to each pixel in the surrounding image, and the image coordinates being two-dimensional coordinates;
• a coordinate transformation step of performing coordinate transformation on the two-dimensional image coordinates included in the at least one reference image synthesis parameter obtained by the image synthesis parameter obtainment step, using the coordinate transformation parameter obtained by the coordinate transformation parameter obtainment step, and of outputting the image coordinates as a transformed image synthesis parameter indicating transformed two-dimensional image coordinates;
• and
• an image synthesis step of generating the surrounding image by applying the transformed image synthesis parameter to the captured image, and of outputting the generated surrounding image,
• wherein the image synthesis step reads, from among pixels included in the captured image, an image of a pixel located in the transformed two-dimensional image coordinates indicated by the transformed image synthesis parameter, and outputs the read image as an image of a pixel located in the surrounding image and corresponding to the pixel located in the transformed two-dimensional image coordinates.