Vehicle monitoring apparatus

A monitoring apparatus mounted on a vehicle for watching an object in a vicinity thereof, having a pair of stereoscopic CCD cameras mounted on a front portion of said vehicle for obtaining a distance image including an image data and a three-dimensional distance information about said object and for producing an image signal, comprising:

• stereoscopic image processing means responsive to said image signal for deriving a distance information about said object and for transmitting a distance signal;
• means for forming groups based on said distance information;
• road detecting means responsive to said distance signal for deriving a road shape by extracting a line painted on a road in front of said vehicle and for outputting a road signal;
• group filtering means responsive to said distance signal and said road signal for calculating an area of each group after distinguishing whether a deviation of said distance image is within a predetermined criteria and for producing an area signal;
• data extracting means responsive to said area signal for extracting area signals larger than a predetermined threshold value and for outputting a data signal;
• and
• object distance deriving means responsive to said data signal for calculating an exact distance from said vehicle to said object in said each group by making a histogram through eliminating false data so as to be precisely detectable of an unevenness of a surface of said object.

A vehicle monitoring method for obtaining a distance image including an image data and a three-dimensional distance information and for monitoring surrounding conditions on the basis of said distance image, the method comprising the steps of:

• dividing said distance image into a plurality of blocks composed of at least one picture element;
• grouping said blocks having a similar distance data into an independent group;
• calculating an area size of said independent group;
• extracting said image data as an object data if said area size is larger than a predetermined value;
• discarding said image data as false data if said area size is smaller than said predetermined value;
• preparing a histogram on the basis of the image data thus extracted, said histogram having a lateral axis representing a deviation amount and a longitudinal axis representing a frequency corresponding to a number of said image data;
• and
• detecting an object and a distance to said object by deleting said frequency having a smaller number of said image data than a threshold value along said lateral axis on said histogram.

A monitoring method of a vehicle for watching an object in a vicinity thereof, having a pair of stereoscopic CCD cameras mounted on a front portion of said vehicle for obtaining a distance image including an image data and a three-dimensional distance information about said object, comprising the steps of:

• deriving a distance information about said object from said distance images;
• determining a plurality of groups based on said distance information;
• calculating an area of each of said groups;
• imaging a road shape by extracting a line painted on a road in front of said vehicle;
• calculating a three dimensional coordinate value of said object;
• determining values which exceed a predetermined threshold value;
• deciding an area of corresponding group by referring to a memory;
• determining larger values of said area than a predetermined value;
• rewriting a histogram data of said larger values by comparing a frequency thereof;
• and
• detecting a distance of said object by counting a number of deviations from said frequency so as to be precisely detectable of an unevenness of a surface of said object.