Stereo Camera Apparatus

Abstract

A stereo camera apparatus which carries out distance measuring stably and with high accuracy by making measuring distance resolution variable according to a distance to an object is provided. A stereo camera apparatus 1 takes in two images, changes resolution of a partial area of each image that is taken in, and calculates a distance from a vehicle to an object that is imaged in the partial area, based on disparity of the partial area of each image in which resolution is changed. Thus, even when the object exists at a long distance and is small in size, distance measuring processing can be carried out stably.

1 . A stereo camera apparatus which measures a distance to an object, using two images picked up by two cameras, comprising:
 an image capture unit which takes in the two images;   an image generating unit which changes resolution of a area of each image taken in by the image capture unit; and   a distance calculating unit which calculates a distance from the vehicle to an object that is imaged in the partial area, based on disparity of the partial area of each image in which resolution is changed by the image generating unit.   
     
     
         2 . The stereo camera apparatus according to  claim 1 , wherein the image generating unit changes the resolution of the area of the each image, based on traveling environment information. 
     
     
         3 . The stereo camera apparatus according to  claim 2 , wherein the traveling environment information includes information of the distance from the vehicle to the object. 
     
     
         4 . The stereo camera apparatus according to  claim 2 , wherein the traveling environment information includes at least one information of a vehicle speed of the vehicle, a relative speed between the vehicle and the object, and a traveling direction of the vehicle and the object. 
     
     
         5 . The stereo camera apparatus according to  claim 1 , wherein the image generating unit regards, as the area of the each image, a horizontally divided area in the each image based on the distance from the vehicle as a parameter. 
     
     
         6 . The stereo camera apparatus according to  claim 1 , wherein the image generating unit regards plural areas in the each image as the partial area of the each image. 
     
     
         7 . The stereo camera apparatus according to  claim 1 , wherein the image generating unit calculates the distance from the vehicle to the object, based on disparity of each image taken in by the image capture unit, and changes the resolution of the area of the each image based on the calculated distance. 
     
     
         8 . The stereo camera apparatus according to  claim 1 , wherein the image generating unit changes the resolution of the area of the each mage based on the distance from the vehicle to the object, in such a way that a number of pixels including the object becomes a number of pixels that is preset according to a type of the object. 
     
     
         9 . The stereo camera apparatus according to  claim 1 , wherein the image generating unit changes the resolution to a high resolution when the distance from the vehicle to the object is longer than a preset first standard distance. 
     
     
         10 . The stereo camera apparatus according to  claim 9 , wherein the image generating unit changes the resolution to a high resolution by improving the resolution in vertical direction. 
     
     
         11 . The stereo camera apparatus according to  claim 1 , wherein when plural objects are imaged in the partial area, the image generating unit selects an object with top priority based on a order of priority, and decides the resolution of the area of the each image based on the selected object. 
     
     
         12 . The stereo camera apparatus according to  claim 1 , wherein the image generating unit carries out processing to deform a shape of the area in such a way that an image size of the area of the each image becomes the same as before change. 
     
     
         13 . The stereo camera apparatus according to  claim 1 , wherein the apparatus includes a resolution lowering means which lowers the resolution of each image taken in by the image capture unit, and
 when the distance from the vehicle to the object is shorter than a preset first standard distance, the distance calculating unit calculates the distance from the vehicle to the object based on disparity of the area of each image in which the resolution is changed by the image generating unit, and when the distance from the vehicle to the object is longer than a preset second standard distance, the distance calculating unit calculates the distance from the vehicle to the object based on disparity of each image taken in by the image capture unit.