1. A detection apparatus for detecting an object to be detected in a first image and a second image captured by two imaging systems at a same timing, comprising: an integral image calculation section that calculates a first integral image and a second integral image from the first image and the second image; an acquisition section that acquires a unit image pair composed of a first unit image and a second unit image, from the first integral image and the second integral image, wherein a plurality of unit image pairs cut out at different positions from each other are acquired by sequentially shifting the cutout positions of the unit images; a setting section that sets, with respect to each of the unit image pairs, M cross region patterns (M is a natural number not less than 2), each of the M cross region patterns being defined by positions and sizes of N setting regions (N is a natural number not less than 2) within the respective unit images, and setting image information indicating whether the respective setting regions are set within the first unit image or the second unit image; a feature value calculation section that calculates a feature value in each of the image regions where the cross region patterns are set by the setting section, and calculates a total feature value for each of the cross region patterns from the calculated feature values; and a detection section that detects the object to be detected based on the total feature value for each of the M cross region patterns and a strong classifier composed of a plurality of weak classifiers each corresponding to each of the M cross region patterns.