A document image processor reads data on the image of an original document and automatically sets a format for the document in a document processor such as a word processor or personal computer. First, an image scanner reads a document as image data. A character recognizer recognizes and encodes a character from the read image data, and a document processor stores the encoded document data into a document memory. When the character recognizer encodes the image data, it analyzes the structure of the document. The document processor produces format information on the basis of the result of the analysis, and sets the produced format information in the document format memory in correspondence to document data in the document memory. Thus, the document image processor reads a document image from the document, encodes the image, and sets a format for a document conforming exactly to the document image in correspondence to the encoded document data.