1. An image modification system usable in an image recording apparatus comprising: memory means for temporarily storing a part of bit information from bit information generated by a bit information generator; means for extracting predetermined plural areas, each such area consisting of plural bit information, from the part of bit information stored in said memory means; feature matching means for detecting whether the part of bit information stored in said memory means coincides with one predetermined feature of predetermined plural features; judging means for judging whether or not the part of bit information stored in said memory means is bit information for a half-tone image; and information modifying means for modifying print information of an object pixel which corresponds to a bit in the part of bit information stored in said memory means, in a case where both said feature matching means detects coincidence with said one predetermined feature of the predetermined plural features and said judging means judges that the part of bit information stored in said memory means is not bit information for a half-tone image.