High-accuracy character recognition has not been realized for a document having a space between lines is narrow, a document in which line contact occurs at a plurality of positions, and a document in which a ratio of lines with line contact is high. Noises are removed from divided line images that are obtained by dividing a text image into line units, and the removed noises are added to a neighboring divided text line image, thus restoring the character image which has been divided into the plurality of lines. This realizes the high-accuracy character recognition.