초록 ▼

The invention provides an identification data insertion and detection system for digital data which improves the detection ratio when an image is converted into frequency components and electronic watermark data are embedded in a portion of an image having a strong frequency component and besides al

The invention provides an identification data insertion and detection system for digital data which improves the detection ratio when an image is converted into frequency components and electronic watermark data are embedded in a portion of an image having a strong frequency component and besides allows a statistical similarly to be calculated with a higher degree of accuracy. The identification data insertion system for digital data includes a DCT calculator for extracting blocks of 8.times.8 pixels from within a current image and performing DCT (discrete cosine transform) calculation for the blocks, a quantizer for quantizing data outputted from the DCT calculator, a quantization table for being referred to when the quantizer performs quantization, an electronic watermark data insertion element for inserting electronic watermark data into data after quantization, and an encoder for encoding data outputted from the electronic watermark data insertion element to produce MPEG data in which the electronic watermark data are inserted and outputting the MPEG data.

대표청구항 ▼

1. An electronic watermark insertion apparatus, comprising:conversion means for performing discrete cosine transform for an original image to convert the original image into data f(i) of frequency components, i being 1, 2, . . . , n; electronic watermark insertion means for multiplying a partial ave

1. An electronic watermark insertion apparatus, comprising:conversion means for performing discrete cosine transform for an original image to convert the original image into data f(i) of frequency components, i being 1, 2, . . . , n; electronic watermark insertion means for multiplying a partial average of the data f(i) and electronic watermark data w(i) determined in advance for the individual factors (i), i being 1, 2, . . . , n, and adding the data f(i) to the results obtained by multiplying the results of the multiplication by a constant to determine an electronic watermark containing data F(i), i being 1, 2, . . . , n; quantization means for quantizing the data F(i) with a quantization step sizes Q(i), i being 1, 2, . . . , n; and coding means for compression coding the data after the quantization; the partial average of the data f(i) being given by (V(i-1)+V(i)+V(i+1))/3 where V(i-1)=`integral part of (f(i-1)/Q(i-1).times.Q(i-1)`, V(i)=`integral part of (f(i)/Q(i).times.Q(i)`, and V(i+1)=`integral part of (f(i+1)/Q(i+1).times.Q(i+1)`.