1. A manipulation input device comprising: a hand region detection unit for detecting a hand region in a captured image obtained by imaging by an image capture unit; a light source presence degree information generating unit for setting a light source presence degree as an index indicating a probability that a light source is present, for each part of a background region comprising a region other than the hand region detected by the hand region detection unit, on a basis of luminance or color of the part; a light source estimation unit for estimating, on a basis of the light source presence degree, a light source region which is a region affected by a light source in the captured image, and determining whether or not the estimated light source region and the hand region detected by the hand region detection unit are within a predetermined distance of each other; a shape analysis/evaluation unit for making a decision, on a basis of a shape of the hand region detected by the hand region detection unit, as to whether or not a dropout has occurred in the hand region in the captured image, when the estimated light source region and the hand region are determined to be within the predetermined distance of each other; and an action determination unit for making a determination of an action of a hand on a basis of a result of the decision made by the shape analysis/evaluation unit and information representing the hand region detected by the hand region detection unit.