| 主权项 |
1. A biometric authentication apparatus comprising:
a light source configured to irradiate light on a biometric target; an imaging device configured to capture an image including the biometric target; a storage configured to store a correction coefficient for each of a plurality of positions on a reference object, the correction coefficient being represented by α(x, y)=P/{Ir(x, y)·Dr2(x, y)}, where P denotes a constant, Ir(x, y) denotes a luminance value at x and y coordinates of a captured image of the reference object, (x, y) represents an XY coordinate system in which a center of the captured image of the reference object is located at a center coordinate (0, 0), and Dr denotes a distance from the light source to the x and y coordinates on the reference object that is located at one or a plurality of heights Z=Zr represented in an XYZ coordinate system; and a processor configured to perform a process including
computing a luminance at each of a plurality of positions on the biometric target within the image captured by the imaging device; and correcting the luminance at each of the plurality of positions on the biometric target within the image captured by the imaging device, based on the correction coefficient at each of the plurality of positions on the reference object. |
