1. An information processing device comprising: a light source estimation unit configured to estimate a light source illuminating a predetermined target from an input image; a shaded region recognition unit configured to recognize a shaded region on which shading occurs due to the light source in the input image based on an estimated result of the light source; a correction information calculation unit configured to obtain a correction coefficient correcting a threshold of the weak learner and to provide correction information; a correction unit configured to correct parameters of an ensemble learner using the correction information for correcting the parameters of the ensemble learner having a plurality of weak learners that receive characteristic amounts extracted from the input image and output weak hypotheses indicating whether or not the predetermined target is reflected in the input image; and a discrimination unit configured to integrate the weak hypotheses output from the weak learners with respect to the characteristic amounts using the ensemble learner of which the parameters are corrected and discriminate whether or not the target is reflected in the input image based on an integrated value of the weak hypotheses; wherein the ensemble learning is carried out using a plurality of learning images which include positive images in which the target is reflected and negative images in which the target is not reflected, and wherein the correction unit corrects the threshold value of the weak learner of which one pixel location is within the shaded region and the other pixel location is outside the shaded region in a pixel location pair by a multiplication value obtained by multiplying a subtraction value by a pixel value of the one pixel location, the subtraction value being obtained by subtracting the correction coefficient, which is equal to or smaller than 1, from 1, in an average image of which the positive images included in the learning image are averaged.