Digital information embedding/extracting apparatus and method, and medium including a program for executing the method recorded thereon

A digital information embedding apparatus for embedding inherent digital information in a digital image signal, comprising:

• a transform coefficient calculation section for decomposing said digital image signal into frequency components and calculating transform coefficients for a plurality of blocks each composed of a predetermined number of pixels;
• a quantization section for quantizing the transform coefficients outputted from said transform coefficient calculation section;
• a mapping section for mapping the inherent digital information with a pseudo-random number sequence;
• an information embedding section for selecting a specific transform coefficients sequence from said quantized transform coefficients and embedding said pseudo-random number sequence in the specific transform coefficients sequence based on a predetermined weight sequence corresponding to elements of the transform coefficients, for each of said blocks;
• and
• an encoding section for encoding said embedding-processed transform coefficients.

A digital information extracting apparatus for extracting inherent digital information embedded in a specific transform coefficients sequence among transform coefficients calculated by decomposing a digital image signal into frequency components by a specific apparatus, comprising:

• a decoding section for receiving compressed data encoded and outputted by said specific apparatus and decoding the compressed data;
• an inverse-quantization section for performing inverse quantization for data outputted from the decoding section;
• a correlation value calculation section for calculating an inner product between said specific transform coefficients sequence among data outputted from said inverse-quantization section and each of a plurality of pseudo-random number sequences including a pseudo-random number sequence associated with said inherent digital information embedded by said specific apparatus;
• a pseudo-random number sequence determination section for determining a pseudo-random number sequence embedded in the data based on a value of the inner product outputted from said correlation value calculation section;
• and
• an information generation section for generating inherent digital information mapped with said determined pseudo-random number sequence.

A digital information extracting apparatus for extracting inherent digital information embedded in a specific quantized transform coefficients sequence among transform coefficients calculated by decomposing a digital image signal into frequency components by a specific apparatus, comprising:

• a decoding section for receiving compressed data encoded and outputted by said specific apparatus and decoding the compressed data;
• a correlation value calculation section for calculating an inner product between said specific quantized transform coefficients sequence among data outputted from said decoding section and each of a plurality of pseudo-random number sequences including a pseudo-random number sequence associated with said inherent digital information embedded by said specific apparatus;
• a pseudo-random number sequence determination section for determining a pseudo-random number sequence embedded in the data based on a value of the inner product outputted from said correlation value calculation section;
• and
• an information generation section for generating inherent digital information mapped with said determined pseudo-random number sequence.

A digital information embedding apparatus for removing only desired digital information among a plurality of digital information embedded in a specific transform coefficients sequence calculated by decomposing a digital image signal into frequency components by a specific apparatus based on a weight sequence, comprising:

• a decoding section for receiving compressed data encoded and outputted by said specific apparatus and decoding the compressed data;
• an inverse-quantization section for performing inverse quantization for data outputted from said decoding section;
• a mapping section for mapping said desired digital information with a pseudo-random number sequence;
• an information embedding section for selecting a specific transform coefficients sequence in which said desired digital information has been embedded from data outputted from said inverse-quantization section, and embedding said pseudo-random number sequence in the specific transform coefficients sequence;
• a quantization section for quantizing said embedding-processed transform coefficients;
• and
• an encoding section for encoding said quantized transform coefficients.

A digital information embedding apparatus for removing only desired digital information among a plurality of digital information embedded in a specific quantized transform coefficients sequence calculated by decomposing a digital image signal into frequency components by a specific apparatus based on a weight sequence, comprising:

• a decoding section for receiving compressed data encoded and outputted by said specific apparatus and decoding the compressed data;
• a mapping section for mapping said desired digital information with a pseudo-random number sequence;
• an information embedding section for selecting a specific quantized transform coefficients sequence in which said desired digital information has been embedded from data outputted from said decoding section, and embedding said pseudo-random number sequence in the specific transform coefficients sequence;
• and
• an encoding section for encoding said embedding-performed transform coefficients.

A digital information embedding method for embedding inherent digital information in a digital image signal, comprising the steps of:

• decomposing said digital image signal into frequency components and calculating transform coefficients for a plurality of blocks each composed of a predetermined number of pixels;
• mapping the inherent digital information with a pseudo-random number sequence;
• selecting a specific transform coefficients sequence from said calculated transform coefficients, and embedding said pseudo-random number sequence in the specific transform coefficients sequence based on a predetermined weight sequence corresponding to elements of the transform coefficients, for each of said blocks;
• quantizing said embedding-processed transform coefficients;
• and
• encoding said quantized transform coefficients.

A digital information embedding method for embedding inherent digital information in a digital image signal, comprising the steps of:

• decomposing said digital image signal into frequency components and calculating transform coefficients for a plurality of blocks each composed of a predetermined number of pixels;
• quantizing said calculated transform coefficients;
• mapping the inherent digital information with a pseudo-random number sequence;
• selecting a specific transform coefficients sequence from the quantized transform coefficients, and embedding said pseudo-random number sequence in the specific transform coefficients sequence based on a predetermined weight sequence corresponding to elements of the transform coefficients, for each of said blocks;
• and
• encoding said embedding-processed transform coefficients.

A digital information extracting method for extracting inherent digital information embedded in a specific transform coefficients sequence among transform coefficients calculated by decomposing a digital image signal into frequency components by a specific apparatus, said method comprising the steps of:

• receiving compressed data encoded and outputted by said specific apparatus and decoding the compressed data;
• performing inverse quantization for said decoded data;
• calculating an inner product between said specific transform coefficients sequence among said inverse-quantized data and each of a plurality of pseudo-random number sequences including a pseudo-random number sequence associated with said inherent digital information embedded by said specific apparatus;
• determining a pseudo-random number sequence embedded in the data based on a calculated value of said inner product;
• and
• generating inherent digital information mapped with said determined pseudo-random number sequence.

A digital information extracting method for extracting inherent digital information embedded in a specific quantized transform coefficients sequence among transform coefficients calculated by decomposing a digital image signal into frequency components by a specific apparatus, said method comprising the steps of:

• receiving compressed data encoded and outputted by said specific apparatus and decoding the compressed data;
• calculating an inner product between said specific quantized transform coefficients sequence among said decoded data and each of a plurality of pseudo-random number sequences including a pseudo-random number sequence associated with said inherent digital information embedded by said specific apparatus;
• determining a pseudo-random number sequence embedded in the data based on a calculated value of said inner product;
• and
• generating inherent digital information mapped with said determined pseudo-random number sequence.

A digital information embedding method for removing only desired digital information among a plurality of digital information embedded in a specific transform coefficients sequence calculated by decomposing a digital image signal into frequency components by a specific apparatus, said method comprising the steps of:

• receiving compressed data encoded and outputted by said specific apparatus and decoding the compressed data;
• performing inverse quantization for said decoded data;
• mapping said desired digital information with a pseudo-random number sequence;
• selecting a specific transform coefficients sequence in which said desired digital information has been embedded from said inverse-quantized data, and embedding said pseudo-random number sequence in the specific transform coefficients sequence;
• quantizing said embedding-processed transform coefficients;
• and
• encoding said quantized transform coefficients.

A digital information embedding method for removing only desired digital information among a plurality of digital information embedded in a specific quantized transform coefficients sequence calculated by decomposing a digital image signal into frequency components by a specific apparatus, said method comprising the steps of:

• receiving compressed data encoded and outputted by said specific apparatus and decoding the compressed data;
• mapping said desired digital information with a pseudo-random number sequence;
• selecting a specific quantized transform coefficients sequence in which said desired digital information has been embedded from said decoded data, and embedding said pseudo-random number sequence in the specific transform coefficients sequence;
• and
• encoding said embedding-processed transform coefficients.

A recording medium including a program to be executed by a computer recorded thereon, the program at least executing the steps of:

• decomposing said digital image signal into frequency components and calculating transform coefficients for a plurality of blocks each composed of a predetermined number of pixels;
• mapping the inherent digital information with a pseudo-random number sequence;
• selecting a specific transform coefficients sequence from said calculated transform coefficients, and embedding said pseudo-random number sequence in the specific transform coefficients sequence based on a predetermined weight sequence corresponding to elements of the transform coefficients, for each of said blocks;
• quantizing said embedding-processed transform coefficients;
• and
• encoding said quantized transform coefficients.

A recording medium including a program to be executed by a computer recorded thereon, the program at least executing the steps of:

• receiving encoded compressed data including inherent digital information embedded in a specific transform coefficients sequence calculated by decomposing a digital image signal into frequency components, and decoding the compressed data;
• performing inverse quantization for said decoded data;
• calculating an inner product between said specific transform coefficients sequence among said inverse-quantized data and each of a plurality of pseudo-random number sequences including a pseudo-random number sequence associated with said inherent digital information embedded by said specific apparatus;
• determining a pseudo-random number sequence embedded in the data based on a calculated value of said inner product;
• and
• generating inherent digital information mapped with said determined pseudo-random number sequence.

A recording medium including a program to be executed by a computer recorded thereon, the program at least executing the steps of:

• receiving encoded compressed data including a plurality of inherent digital information embedded in a specific transform coefficients sequence calculated by decomposing a digital image signal into frequency components, and decoding the compressed data;
• performing inverse quantization for said decoded data;
• mapping said desired digital information with a pseudo-random number sequence;
• selecting a specific transform coefficients sequence in which said desired digital information has been embedded from said inverse-quantized data, and embedding said pseudo-random number sequence in the specific transform coefficients sequence;
• quantizing said embedding-processed transform coefficients;
• and
• encoding said quantized transform coefficients.