Image processing apparatus, image processing method, and providing medium

An image processing apparatus for performing processing for decoding an information-embedded image into an original image and original information, said apparatus comprising:

• selection means for selecting a pixel of the image-embedded information;
• processing means for performing predetermined processing on the pixel selected by said selection means;
• correlation calculation means for calculating a first correlation between the pixel selected by said selection means and a peripheral pixel around the selected pixel, and for calculating a second correlation between the pixel selected by said selection means and processed by said processing means and the peripheral pixel around the pixel;
• comparison means for comparing the first correlation and the second correlation;
• and
• decoding means for decoding the pixel selected by said selection means and the information embedded in the pixel based on a result obtained by said comparison means.

An image processing method for performing processing for decoding information-embedded image into an original image and original information, said method comprising:

• a selection step of selecting a pixel of the information-embedded image;
• a processing step of performing predetermined processing on the pixel selected in said selection step;
• a correlation calculation step of calculating a first correlation between the pixel selected in said selection step and a peripheral pixel around the selected pixel, and calculating a second correlation between the pixel selected in said selection step and processed in said processing step and the peripheral pixel around the pixel;
• a comparison step of comparing the first correlation and the second correlation;
• and
• a decoding step of decoding the pixel selected in said selection step and the information embedded in the pixel based on a result obtained in said comparison step.

A computer-readable medium for storing a computer program for enabling a computer to perform processing for decoding information-embedded image into an original image and original information, said computer program comprising:

• a selection step of selecting a pixel of the information-embedded image;
• a processing step of performing predetermined processing on the pixel selected in said selection step so that a correlation between the pixel and adjacent pixels to the pixel becomes smaller selectively;
• a correlation calculation step of calculating a first correlation between the pixel selected in said selection step and a peripheral pixel around the selected pixel, and calculating a second correlation between the pixel selected in said selection step and processed in said processing step and the peripheral pixel around the pixel;
• a comparison step of comparing the first correlation and the second correlation;
• and
• a decoding step of decoding the pixel selected in said selection step and the information embedded in the pixel based on a result obtained in said comparison step.

An image processing apparatus including a transmitter for transmitting an information-embedded image obtained by embedding information and a receiver for receiving the information-embedded image from said transmitter and for decoding the image,

• said transmitter comprising:
• first selection means for selecting a pixel of the image;
• first processing means for performing processing on the pixel selected by said first selection means according to the information so that the pixel is reproducible by utilizing a correlation of the image, thereby embedding the information in the pixel and outputting the information-embedded image,
• said receiver comprising:
• second selection means for selecting a pixel of the information-embedded image;
• second processing means for performing predetermined processing on the pixel selected by said second selection means;
• correlation calculation means for calculating a first correlation between the pixel selected by said second selection means and a peripheral pixel around the selected pixel, and for calculating a second correlation between the pixel selected by said second selection means and processed by said second processing means and the peripheral pixel around the pixel;
• comparison means for comparing the first correlation and the second correlation;
• and
• decoding means for decoding the pixel selected by said second selection means and the information embedded in the pixel based on a result obtained by said comparison means.

An image processing method for use in an image processing apparatus including a transmitter for transmitting an information-embedded image obtained by embedding information and a receiver for receiving the information-embedded image from said transmitter and for decoding the image, said method comprising the steps of:

• selecting a pixel of the image by said transmitter;
• performing processing by said transmitter on the selected pixel according to the information so that the pixel is reproducible by utilizing a correlation of the image, thereby embedding the information in the pixel and outputting the information-embedded image;
• selecting the pixel of the information-embedded image by said receiver;
• performing predetermined processing by said receiver on the selected pixel;
• calculating by said receiver a first correlation between the pixel selected from the information-embedded image and a peripheral pixel around the selected pixel, and calculating a second correlation between the pixel selected from the information-embedded image and undergone the predetermined processing and the peripheral pixel around the pixel;
• comparing the first correlation and the second correlation by said receiver;
• and
• decoding the pixel selected from the information-embedded image and the information embedded in the pixel by said receiver based on a result of comparison.