1. An image processing device comprising: a classification unit configured to classify object-related information indicating a feature of an object into an attribute; a generation unit configured to generate feature information of a partial area of an image by executing object recognition processing on the image; a first calculation unit configured to calculate a degree of similarity between the object and the partial area based on the object-related information and the feature information; an estimation unit configured to estimate the object for each partial area based on the degree of similarity; a second calculation unit configured to calculate, for each attribute, a total of degrees of similarity between the object-related information classified into the attribute and the partial area, for a combination of estimated objects; a selection unit configured to select at least one of the combination of the estimated objects based on the total; and a storage unit configured to store the object included in a selected combination in association with the image.