the object of this invention is to provide an image processing device and image input device which creates strong features , or enhanced pattern which could be recognized when the image was read and which would prove difficult to eliminate through subsequent image processing . when the image is generated at the later step , these features would be easily recognized by the processing according to this invention because the image is equipped with the enhanced pattern which is easy to detect . in order to achieve this object , the image processing device according to this invention is equipped with a data synthesizing unit to synthesize the clear target pattern on the candidate target pattern which is not fully clear when the recognition unit has detected a pattern similar to the target pattern .