1. An image recognition apparatus configured to recognize an object in an input image, the apparatus comprising: a database in which an image or an image feature obtained by imaging an object, and an object recognizability state of the object are registered as registered image information in association with an identification of the object; a first calculation unit configured to calculate a coincidence degree between an object recognizability state of an input object image and an object recognizability state in the registered image information; a second calculation unit configured to calculate a similarity between an image feature of the input object image and an image feature in the registered image information; and a recognition unit configured to execute recognition processing to recognize, based on the similarity and the coincidence degree, whether an object of the input object image is the same object as the object of the registered image information, wherein when the second calculation unit calculates that the similarity is lower than a first threshold and the first calculation unit calculates that the coincidence degree is equal to or higher than a second threshold, said recognition unit is configured to recognize that the object of the input object image is different from the object of the registered image information.