Road surface detecting apparatus

A road surface detecting apparatus mounted on a vehicle comprising;

• a stereo camera for taking a stereo image of a region in front of said vehicle;
• a processor;
• a non-transitory computer-readable storage medium;
• and
• a set of computer-executable instructions stored on said computer-readable storage medium that cause said processor to implement:
• calculating, based on a stereo image taken by said stereo camera, parallax information including a parallax of each of pixels composing said stereo image;
• extracting, based on said parallax information, a pixel corresponding to a road surface from said pixels of said stereo image;
• acquiring, based on information of said extracted pixel, information-indicating-a-road-surface in three-dimensional coordinate axes as road surface information;
• calculating, based on said information-indicating-a-road-surface, a road surface gradient formula by approximating a gradient of said road surface by a polynomial function;
• determining whether or not an absolute value of a coefficient of a term with a highest degree of said road surface gradient formula is greater than a predetermined coefficient threshold;
• and
• invalidating said information-indicating-a-road-surface when it is determined that said absolute value is greater than said coefficient threshold.

A non-transitory computer-readable storage medium having computer-executable instructions, said instructions comprising;

• acquiring a set of images of a region in front of a vehicle, said set of images being taken by a stereo camera;
• calculating, based on said set of images, parallax information including a parallax of each of pixels composing said set of images;
• extracting, based on said parallax information, a pixel corresponding to a road surface from said pixels of said set of images;
• acquiring, based on information of said extracted pixel, information-indicating-a-road-surface in three-dimensional coordinate axes as road surface information;
• calculating, based on said information-indicating-a-road-surface, a road surface gradient formula by approximating a gradient of said road surface by a polynomial function;
• determining whether or not an absolute value of a coefficient of a term with a highest degree of said road surface gradient formula is greater than a predetermined coefficient threshold;
• and
• invalidating said information-indicating-a-road-surface when it is determined that said absolute value is greater than said coefficient threshold.