An image processing apparatus specifies an evaluation-target area that tends to produce distortion in an object contained in an image, and calculates amount of distortion produced in vectorization of the object by comparing the shape of the object and the shape of a vectorized object obtained by vectorizing the object in the specified evaluation-target area. The apparatus further revises the shape of the vectorized object in the evaluation-target area so as to approach the shape of the object when the amount of distortion is larger than a predetermined reference value.