Contents of manual retouching performed on a portion of an input image are reflected to the entire portion of the image. Weighting parameters, each representing pre- and post-retouching state of a manually retouched area of a predetermined structure in a retouching target image, and pre-retouching state of the entire portion of the structure, are obtained by applying the area in pre- and post-retouching state, and the entire portion of the structure in pre-retouching state to a model that represents at least the shape of the area or the entire portion of the structure. Then, a parameter representing the entire portion of the structure after the contents of the manual retouching are reflected to the entire portion of the structure is determined based on the obtained weighting parameters, and an image of entirely reconstructed structure is generated based on the determined parameter and the model.