Patent ID: 8433099

Claim:
A vehicle discrimination apparatus for discriminating a vehicle on the basis of an image of the vehicle, the vehicle discrimination apparatus comprising: a processor to determine grid points on the image, the grid points being pixels defined as vertices of grids formed by predefined vertical grid lines and predefined horizontal grid lines; extract intensity components of pixels corresponding to the determined grid points and neighboring pixels thereof, the neighboring pixels not being vertices of grids formed by the predefined vertical grid lines and the predefined horizontal grid lines; apply a differential filter on values of the extracted intensity components to obtain variations in the intensity components of pixels corresponding to the grid points, and discriminate the vehicle on the basis of data derived from the obtained variations in the intensity components of the pixels corresponding to the grid points; wherein the processor further calculates a specific vertically projected value ratio by accumulating along the vertical grid lines the obtained variations-to obtain vertically projected values, extracting a predefined number of the vertically projected values in descending order, accumulating, among the vertically projected values extracted, the vertically projected values accumulated along adjacent vertical grid lines to obtain a specific vertically projected value, and obtaining, as the specific vertically projected value ratio, a ratio of the specific vertically projected value against an accumulated value of variations in the intensity components of pixels corresponding to all the grid points, and the processor discriminates the vehicle on the basis of the obtained specific vertically projected value ratio.