1. An image processing apparatus comprising: a projection unit configured to project, onto an object, a projection pattern; a capturing unit configured to capture the object onto which the projection pattern has been projected; and a measurement unit configured to: measure approximate distance information of the object based on the projection pattern projected by the projection unit and an image captured by the capturing unit; determine, on the basis of the measured approximate distance information, whether each region of the projection pattern included in the image captured by the capturing unit blurs; and measure, for a region determined as blurring, distance information to the object on the basis of correlation between (1) the image captured by the capturing unit and (2) an image obtained by performing blurring processing for the projection pattern.