1. An object recognition system comprising a template memory configured to store an image size template (T); an image reader configured to take a subject image (S) to be recognized; a mask locator configured to locate a mask area (M) from within said subject image, said mask area (M) corresponding to said image size template (T), and wherein said mask locator comprising: an image converter configured to convert said image size template (T) as well as said subject image (S) respectively into a density gradient directional template image (DT) and a density gradient directional subject image (DS), each of said directional images having an array of pixels each storing a density gradient directional value (θT, θS) assigned thereto; a feature analyzer configured to select a plurality of reference points (R 0 ,. .. Rn) around a predetermined center point (C T ) within said directional template image (DT) and to obtain a distance (L) and an angle (α) for each of said reference points, said distance (L) being a length of a line extending from said center point to said reference point, and said angle (α) being an angle of said line with respect to a horizontal axis; a table configured to store, for each of said reference points, said distance (L) and angle (α) in association with said density gradient directional value (θT) given to each of said reference points (Ro,. .. Rn); a vote module configured to: obtain said density gradient directional value (θS) for each pixel of said directional subject image (DS), read from said table parameters composed of the distance (L), the angle (α), and coordinates with regard to the reference points having the same density gradient directional value (θT=θS), so as to calculate a plurality of candidates for a center of said mask area (M) based upon these parameters and to make a vote on each of said candidates; a detection module configured to designate at least one of said candidates as the center of said mask area (M) according to the number of said votes, thereby determining said mask area (M) around thus designated center within said subject image.