Image processing apparatus and method, computer program, and computer-readable storage medium

An image processing apparatus which removes visible additional information from multilevel image data in which noise is reversibly embedded to multiplex the visible additional information, comprising:

• input means for inputting, as the additional information, information representing whether or not to multiplex noise for each pixel;
• determination means for determining on the basis of the additional information whether a pixel of interest in the multilevel image data is located at a position where noise is multiplexed;
• specifying means for, when said determination means determines that the pixel of interest is located at the position where noise is multiplexed, specifying a second bit region where noise is multiplexed on-the basis of a state of a first bit region in a bit configuration which constitutes the pixel of interest;
• and
• reconstruction means for performing conversion inverse to noise multiplexing to reconstruct a state of the second bit region of the pixel of interest specified by said specifying means into a state before multiplexing.

An image processing apparatus which converts multilevel image data into frequency component data for each pixel block of a predetermined size to compression-code the multilevel image data, and multiplexes noise on the multilevel image to embed visible additional information with a noise-multiplexed distribution, comprising:

• input means for inputting, as the additional information, information representing whether or not to multiplex noise for each pixel block of the predetermined size;
• determination means for determining on the basis of the input additional information whether a pixel block of interest is located at a position where noise is to be multiplexed;
• specifying means for, when said determination means determines that the pixel block of interest is located at the position where noise is to be multiplexed, specifying a second bit region where noise is to be multiplexed, on the basis of a state of a first bit region in data which constitutes a low frequency component after conversion of the pixel block of interest;
• and
• change means for reversibly changing bit information for the second bit region in the data of the low frequency component specified by said specifying means.

An image processing apparatus which removes visible additional information from multilevel image data that is compression-coded by reversibly embedding noise, multiplexing the visible additional information, and converting the data into frequency component data for each pixel block of a predetermined size, comprising:

• input means for inputting, as the additional information, information representing whether or not to multiplex noise for each pixel block of the predetermined size;
• determination means for determining on the basis of the input additional information whether a pixel block of interest is located at a position where noise is multiplexed;
• specifying means for, when said determination means determines that the pixel block of interest is located at the position where noise is multiplexed, specifying a noise-multiplexed second bit region on the basis of a state of a first bit region in data which constitutes a low frequency component after frequency conversion of the pixel block of interest;
• and
• reconstruction means for performing conversion inverse to noise multiplexing to reconstruct a state of the second bit region of the pixel block of interest specified by said specifying means into a state before multiplexing.

An image processing method of multiplexing noise on multilevel image data to embed visible additional information with a noise-multiplexed distribution, comprising:

• an input step of inputting, as the additional information, information representing whether or not to multiplex noise for each pixel;
• a determination step of determining on the basis of the additional information whether a pixel of interest in the multilevel image data is located at a position where noise is to be multiplexed;
• a specifying step of, when the pixel of interest is determined in the determination step to be located at the position where noise is to be multiplexed, specifying a second bit region where noise is to be multiplexed, on the basis of a state of a first bit region in a bit configuration which constitutes the pixel of interest;
• and
• a change step of reversibly changing bit information for the second bit region of the pixel of interest specified in the specifying step.

An image processing method of removing visible additional information from multilevel image data in which noise is reversibly embedded to multiplex the visible additional information, comprising:

• an input step of inputting, as the additional information, information representing whether or not to multiplex noise for each pixel;
• a determination step of determining on the basis of the additional information whether a pixel of interest in the multilevel image data is located at a position where noise is multiplexed;
• a specifying step of, when the pixel of interest is determined in the determination step to be located at the position where noise is multiplexed, specifying a second bit region where noise is multiplexed on the basis of a state of a first bit region in a bit configuration which constitutes the pixel of interest;
• and
• a reconstruction step of performing conversion inverse to noise multiplexing to reconstruct a state of the second bit region of the pixel of interest specified in the specifying step into a state before multiplexing.

An image processing method of converting multilevel image data into frequency component data for each pixel block of a predetermined size to compression-code the multilevel image data, and multiplexing noise on the multilevel image to embed visible additional information with a noise-multiplexed distribution, comprising:

• an input step of inputting, as the additional information, information representing whether or not to multiplex noise for each pixel block of the predetermined size;
• a determination step of determining on the basis of the input additional information whether a pixel block of interest is located at a position where noise is to be multiplexed;
• a specifying step of, when the pixel block of interest is determined in the determination step to be located at the position where noise is to be multiplexed, specifying a second bit region where noise is to be multiplexed, on the basis of a state of a first bit region in data which constitutes a low frequency component after conversion of the pixel block of interest;
• and
• a change step of reversibly changing bit information for the second bit region in the data of the low frequency component specified in the specifying step.

An image processing method of removing visible additional information from multilevel image data that is compression-coded by reversibly embedding noise, multiplexing the visible additional information, and converting the data into frequency component data for each pixel block of a predetermined size, comprising:

• an input step of inputting, as the additional information, information representing whether or not to multiplex noise for each pixel block of the predetermined size;
• a determination step of determining on the basis of the input additional information whether a pixel block of interest is located at a position where noise is multiplexed;
• a specifying step of, when the pixel block of interest is determined in the determination step to be located at the position where noise is multiplexed, specifying a noise-multiplexed second bit region on the basis of a state of a first bit region in data which constitutes a low frequency component after frequency conversion of the pixel block of interest;
• and
• a reconstruction step of performing conversion inverse to noise multiplexing to reconstruct a state of the second bit region of the pixel block of interest specified in the specifying step into a state before multiplexing.

A computer program functioning as an image processing apparatus which multiplexes noise on multilevel image data to embed visible additional information with a noise-multiplexed distribution, functioning as:

• input means for inputting, as the additional information, information representing whether or not to multiplex noise for each pixel;
• determination means for determining on the basis of the additional information whether a pixel of interest in the multilevel image data is located at a position where noise is to be multiplexed;
• specifying means for, when said determination means determines that the pixel of interest is located at the position where noise is to be multiplexed, specifying a second bit region where noise is to be multiplexed, on the basis of a state of a first bit region in a bit configuration which constitutes the pixel of interest;
• and
• change means for reversibly changing bit information for the second bit region of the pixel of interest specified by said specifying means.

A computer program functioning as an image processing apparatus which removes visible additional information from multilevel image data in which noise is reversibly embedded to multiplex the visible additional information, functioning as:

• input means for inputting, as the additional information, information representing whether or not to multiplex noise for each pixel;
• determination means for determining on the basis of the additional information whether a pixel of interest in the multilevel image data is located at a position where noise is multiplexed;
• specifying means for, when said determination means determines that the pixel of interest is located at the position where noise is multiplexed, specifying a second bit region where noise is multiplexed on the basis of a state of a first bit region in a bit configuration which constitutes the pixel of interest;
• and
• reconstruction means for performing conversion inverse to noise multiplexing to reconstruct a state of the second bit region of the pixel of interest specified by said specifying means into a state before multiplexing.

A computer program functioning as an image processing apparatus which converts multilevel image data into frequency component data for each pixel block of a predetermined size to compression-code the multilevel image data, and multiplexes noise on the multilevel image to embed visible additional information with a noise-multiplexed distribution, functioning as:

• input means for inputting, as the additional information, information representing whether or not to multiplex noise for each pixel block of the predetermined size;
• determination means for determining on the basis of the input additional information whether a pixel block of interest is located at a position where noise is to be multiplexed;
• specifying means for, when said determination means determines that the pixel block of interest is located at the position where noise is to be multiplexed, specifying a second bit region where noise is to be multiplexed, on the basis of a state of a first bit region in data which constitutes a low frequency component after conversion of the pixel block of interest;
• and
• change means for reversibly changing bit information for the second bit region in the data of the low frequency component specified by said specifying means.

A computer program functioning as an image processing apparatus which removes visible additional information from multilevel image data that is compression-coded by reversibly embedding noise, multiplexing the visible additional information, and converting the data into frequency component data for each pixel block of a predetermined size, functioning as:

• input means for inputting, as the additional information, information representing whether or not to multiplex noise for each pixel block of the predetermined size;
• determination means for determining on the basis of the input additional information whether a pixel block of interest is located at a position where noise is multiplexed;
• specifying means for, when said determination means determines that the pixel block of interest is located at the position where noise is multiplexed, specifying a noise-multiplexed second bit region on the basis of a state of a first bit region in data which constitutes a low frequency component after frequency conversion of the pixel block of interest;
• and
• reconstruction means for performing conversion inverse to noise multiplexing to reconstruct a state of the second bit region of the pixel block of interest specified by said specifying means into a state before multiplexing.