1. A digital pictorial book system comprising: an image capturing module for capturing an image: a CPU operating to provide: a main object selecting module for selecting a main object out of the image; an inclination measuring module for measuring inclination of said image capturing module in a vertical direction: a name searching module for searching for a name of the main object in an image database, which stores a name of an object corresponded to a feature of the object, on the basis of the main object selected by said main object selecting module and the inclination measured by said inclination measuring module; a vertical direction image adjusting module for adjusting the image of the main object to be an image captured in a horizontal direction by using the inclination measured by said inclination measuring module: a first feature extracting module for extracting a feature of the main object from the image adjusted by said vertical direction adjusting module; a degree of similarity acquiring module for acquiring degree of similarity between the main object and each of a plurality of objects of which names are stored in the image database by comparing the feature of the main object extracted by said first feature extracting module with that of each of the plurality of objects stored in the image database; and a name selecting module for selecting the name of the main object out of names of the plurality of objects on the basis of the acquired degree of similarity of each of the plurality of objects, wherein said name searching module searches for the name of the main object by using the image adjusted by said vertical direction image adjusting module.