Information-Detecting Apparatus and Method

An information-detecting method comprising:

• receiving digital data that includes several pieces of element data, in which a change amount is imparted to a value of each of first element data and second element data among the several pieces of element data, thereby embedding additional information into both of the first element data and the second element data;
• selecting, as target data, a data set that includes the first element data and the second element data;
• selecting, as neighboring data, element data in proximity to each of the first element data and the second element data;
• calculating, based on both of the target data and the neighboring data, the change amount imparted to each of the first element data and the second element data;
• and
• detecting the additional information in accordance with the change amount.

A recording medium operable to store computer program data comprising:

• receiving digital data that includes several pieces of element data, in which a change amount is imparted to a value of each of first element data and second element data among the several pieces of element data, thereby embedding additional information into both of the first element data and the second element data;
• selecting, as target data, a data set that includes the first element data and the second element data;
• selecting, as neighboring data, element data in proximity to each of the first element data and the second element data;
• calculating, based on both of the target data and the neighboring data, the change amount imparted to each of the first element data and the second element data;
• and
• detecting the additional information in accordance with the change amount.