“…The features regarding license plate format include shape, symmetry [15], height-towidth ratio [23], [25], color [17], [25], texture of grayness [2], [25], spatial frequency [26], and variance of intensity values [8], [10]. Character features include line [34], blob [13], the sign transition of gradient magnitudes, the aspect ratio of characters [12], the distribution of intervals between characters [28], and the alignment of characters [32]. In reality, a small set of robust, reliable, and easy-to-detect object features would be adequate.…”