Image monitoring apparatus for estimating gradient of singleton, and method therefor

An image monitoring apparatus, comprising:

• a singleton selector configured to select at least one singleton from among a plurality of objects in an acquired image;
• a single foreground image generator configured to generate a single foreground image of the singleton;
• an eigenvector extractor configured to extract an eigenvector of a foreground singleton contained in the single foreground image by using at least one selected from the group consisting of (i) a centroid of the foreground singleton, (ii) the number of pixels of the foreground singleton and (iii) coordinate values of the pixels;
• a vanishing point location calculator configured to
• generate a reference vector by connecting a predetermined point in the acquired image to the centroid of the foreground singleton, and
• determine the predetermined point as a vanishing point when the predetermined point minimizes an angle between the reference vector and the eigenvector;
• and
• a gradient determiner configured to
• determine a gradient of the foreground singleton using the vanishing point, and
• correct an inclination and a size of a bounding box of the foreground singleton.