Digital watermark inserting system and digital watermark characteristic parameter table generating method

A record medium from which a computer reads a program that causes the computer to drive a digital watermark inserting system for inserting digital watermark information into an input image, the system comprising:

• means for calculating a feature amount of the input image, categorizing the input image, and outputting a category index as the categorized result;
• digital watermark characteristic calculating means for calculating an image deteriorating ratio and a robustness evaluation value corresponding to a digital watermark strength based on a robustness evaluation value calculation parameter and the category index, the robustness evaluation value calculation parameter being input by the user;
• digital watermark strength calculating means for outputting the digital watermark strength to said digital watermark characteristic calculating means, deciding the optimum digital watermark strength based on digital watermark strength restriction information that is input by the user, and outputting the optimum digital watermark strength;
• and
• digital watermark inserting means for converting input embedding data into digital watermark information, inserting the digital watermark information into the input image with an input parameter of the optimum digital watermark strength, and outputting the resultant image as a digital watermark inserted image.

A record medium from which a computer reads a program that causes the computer to perform a method for inserting digital watermark information into an input image, the method comprising the steps of:

• (a) calculating a feature amount of the input image, categorizing the input image, and outputting a category index as the categorized result;
• (b) digital watermark characteristic calculating means for calculating an image deteriorating ratio and a robustness evaluation value corresponding to a digital watermark strength based on a robustness evaluation value calculation parameter and the category index, the robustness evaluation value calculation parameter being input by the user;
• (c) digital watermark strength calculating means for outputting the digital watermark strength to step (b), deciding the optimum digital watermark strength based on digital watermark strength restriction information that is input by the user, and outputting the optimum digital watermark strength;
• and
• (d) digital watermark inserting means for converting input embedding data into digital watermark information, inserting the digital watermark information into the input image with an input parameter of the optimum digital watermark strength, and outputting the resultant image as a digital watermark inserted image.