Abstract: A document processor for processing a document image which includes both a table formed by a plurality of ruled lines, and characters to generate vector data defining the ruled lines comprises an image input device for reading an image of the document, a display for displaying the document image and a processor for processing the document image. The processor corrects a skew of the input document image, detects a successive black pixel area included in the skew-corrected image, detects a character area based on a size of a rectangle which circumscribes the successive black pixel area, and converts the image to a second document image having characters deleted and including only the ruled lines.