DIGITAL DATA BOOK, DIGITAL DATA BOOK PROCESSING METHOD, DIGITAL DATA BOOK PROCESSING UNIT, AND RECORDING MEDIUM RECORDING DIGITAL DATA BOOK PROCESSING PROGRAM

摘要

PROBLEM TO BE SOLVED: To provide the processing method for digital data books by which whether or not a digital data book is its own work is discriminated and whether or not the digital data book is an illegally copied book is easily discriminated. SOLUTION: The unit 100 divides a digital data book 1 into plural cells, quantizes either white pixels or black pixels in each cell and sets the quantized value with respect to the pixel selected in each cell in the digital data book 1 to a value included in either of two kinds of predetermined object quantization groups. Then a data value in binary-processed data of bit data is made to correspond to a 1st quantization group and the other data value in the binary- processed data of the bit data is made to correspond to a 2nd quantization group. Thus, the digital data book is processed such that security data are imbedded to part of digital data of the book.