Identification data insertion and detection system for digital data

Claim 2

An identification data insertion system for digital data as set forth in claim 1, characterized in that said electronic watermark data insertion element (107) includes a partial average calculator (108) for calculating an average of absolute values of three neighboring points of each factor of the data outputted from said quantizer (104) as a partial average, a first multiplier (110) for multiplying the electronic watermark data by an output of said partial average calculator (108) for the individual factors, a second multiplier (111) for multiplying each factor of an output of said first multiplier (110) by a constant to be used to vary the size of the electronic watermark data to be inserted, and an adder (112) for adding an output of said second multiplier (111) and the output of said quantlzer (104) for the individual factors.

Claim 3

An identification data detection system for digital data, characterized in that it comprises: a decoder (202) for decoding compressed image data; a dequantizer (203) for dequantizing data outputted from said decoder (202); an inverse DCT calculator (204) for performing inverse discrete cosine transform calculation for data outputted from said dequantizer (203) and outputting image data obtained by the inverse discrete cosine transform calculation; an electronic watermark data extractor (206) for extracting and outputting, from among the data outputted from said decoder (202), those data which are supposed to be electronic watermark data; an adder (209) for adding data in units of a block of 8 x 8 pixels outputted from said electronic watermark data extractor (206) for individual factors over one screen; and an inner product calculator (210) for calculating inner products of electronic watermark data to be detected and the data outputted from said adder (209) to calculate a statistical similarity and outputting the statistical similarity.

Claim 4

An identification data detection system for digital data as set forth in claim 3, characterized in that said electronic watermark data extractor (206) includes a partial average calculator (207) for calculating an average of absolute values of three neighboring points of each of data in units of a block of 8 x 8 pixels outputted from said decoder (202) as a partial average, and a divider (208) for dividing the data outputted from said decoder (202) by the partial average outputted from said partial average calculator (207).

Claim 5

An identification data insertion system for digital data, characterized in that it comprises: a DCT calculator (303) for extracting blocks of 8 x 8 pixels from a current image and performing discrete cosine transform calculation for the blocks; an electronic watermark data insertion element (305) for inserting electronic watermark data into data after the discrete cosine transform outputted from said DCT calculator (303); a quantizer (311) for quantizing data outputted from said electronic watermark data insertion element (305); a quantization table (312) for being referred to when said quantizer (311) performs quantization and when said electronic watermark data insertion element (305) calculates a partial average; and an encoder (313) for encoding data outputted from said quantizer (311).

Claim 6

An identification data insertion system for digital data as set forth in claim 5, characterized in that said electronic watermark data insertion element (305) includes a partial average calculator (307) for calculating, using said quantization table (312) when a partial average of the data outputted from said DCT calculator (303) is to be calculated, an average among three neighboring points of absolute values of values obtained each by multiplying an integer value obtained by dividing a value of each factor outputted from said DCT calculator (303) by a corresponding value of said quantization table (312) by the corresponding value of said quantization table (312) as a partial average of the pertaining factor, a first multiplier (308) for multiplying an output of said partial average calculator (307) by the electronic watermark data for the individual factors, a second multiplier (309) for multiplying data outputted from said first multiplier (308) by a constant to be used to vary the size of the electronic watermark data to be embedded, and an adder (310) for adding the data outputted from said DCT calculator (303) and data outputted from said second multiplier (309) for the individual factors.

Claim 7

An identification data detection system for digital data, characterized in that it comprises: a decoder (402) for decoding compressed image data; a dequantizer (403) for dequantizing data outputted from said decoder (402); an inverse DCT calculator (404) for performing inverse discrete cosine transform calculation for data outputted from said dequantizer (403) and outputting image data obtained by the inverse discrete cosine transform calculation; an electronic watermark data extractor (406) for extracting and outputting, from among the data outputted from said dequantizer (403), those data which are supposed to be electronic watermark data; an adder (409) for adding data in units of a block of 8 x 8 pixels outputted from said electronic watermark data extractor (406) for individual factors over one screen; and an inner product calculator (410) for calculating inner products of electronic watermark data to be detected and the data outputted from said adder (409) to calculate a statistical similarity and outputting the statistical similarity.

Claim 8

An identification data detection system for digital data as set forth in claim 7, characterized in that said electronic watermark data extractor (406) includes a partial average calculator (407) for calculating an average of absolute values of three neighboring points of each of data in units of a block of 8 x 8 pixels outputted from said dequantizer (403) as a partial average, and a divider (408) for dividing the data outputted from said dequantizer (403) by the partial average outputted from said partial average calculator (407).

Claim 9

An identification data insertion and detection system for digital data, characterized in that it comprises: an identification data insertion system of claims 1, 2, 5 or 6 and an identification data detection system of claims 3, 4, 7, or 8.