JPH1141453A - Imbedded electronic watermark read processing method, storage medium for imbedded electronic watermark processing program and electronic watermark read processing program storage medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely and comparatively quickly read imbedded electronic water mark information even when cut-and-paste edit is applied to a digital image to which electronic watermark information is imbedded. SOLUTION: In the case of imbeding electronic watermark information, an object is extracted from an original image (10), the position of the block to which electronic watermark information is imbedded is decided so that the object and a block to which electronic watermark information is imbedded have a relation of position according to a rule (12) and then the electronic watermark information is imbedded to the position (13). In the case of reading the electronic watermark information, the object is extracted from the image (20), the position of the block from which electronic watermark information is read is decided so that the object and a block from which electronic watermark information is read have a relation of position according to a rule (22) and then the electronic watermark information is read.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention stores a digital watermark embedding / reading processing method for embedding / reading digital watermark information of an author or a user in a digital image and a program for realizing the method. It relates to a program storage medium.

[0002]

2. Description of the Related Art With the advance of multimedia information processing technology using computers, the importance of protection of so-called digital works has been increasing. To protect digital works, as a means to prevent unauthorized use of works,
There is a technology of digital watermarking (Reference: Nikkei Electronics "" Digital watermarking "protects the multimedia age", n
o.683, 1997, 2-24, p.99-p.124, Nikkei BP).

FIG. 5 is a diagram for explaining an example of the prior art. For example, when embedding digital watermark information in a digital image as shown in FIG.
As shown in (B), a method is adopted in which the vertical direction and the horizontal direction are cut at equal intervals, and digital watermark information is embedded in each block area.

[0004]

In the method described above, a part of the digital image shown in FIG.
When the digital image is pasted to an appropriate place in another digital image as in (C), in order to read the digital watermark information from the cut and pasted digital image, it is necessary to immediately read the digital watermark information because the block boundaries are not known. Cannot be performed and all areas of the image must be searched. Therefore, there is a problem that the processing time for reading the digital watermark information is long.

[0005] The present invention has been made in view of this point,
The purpose is to ensure that even if a digital image in which digital watermark information is embedded is edited by cutting and pasting, the embedded digital watermark information can be read out reliably and relatively quickly. It is.

[0006]

According to the present invention, when embedding digital watermark information in a digital image, the present invention analyzes an original image in which digital watermark information is not embedded, extracts objects in the image, and extracts the extracted object. The position of the block in which the digital watermark information is to be embedded is determined so that the block and the block in which the digital watermark information is to be embedded have a positional relationship according to a certain rule, and the digital watermark information is embedded in the block.

When reading digital watermark information from a digital image, an image including at least a part of the digital image in which the digital watermark information is embedded is analyzed to extract objects in the image. The position of a block from which digital watermark information is read is determined so that the block from which watermark information is read has a positional relationship according to a certain rule, and the digital watermark information is read from the block.

A program for realizing the above processing by a computer can be stored in a suitable storage medium such as a computer-readable portable medium memory, a semiconductor memory, and a hard disk. The present invention can be mainly realized by a general-purpose computer and a software program. However, in extracting an object, embedding digital watermark information in a specific block, and the like, a dedicated device partially using a DSP or the like is used. It is also possible.

[0009]

FIG. 1 is a schematic explanatory diagram of the present invention. In the figure, reference numeral 1 denotes a digital watermark embedding processing device including a CPU and a memory, etc., 2 denotes a digital watermark reading processing device including a CPU and a memory, 3 denotes an original image into which digital watermark information is to be embedded, and 4 denotes a digital watermark embedded image. , 10 to 13 represent processing by the digital watermark embedding processing device, and 20 to 23 represent processing by the digital watermark reading processing device.

The digital watermark embedding processing device 1 performs the following processing. First, in process 10, a digitized original image 3 as shown in FIG. 2A is input, and objects are extracted from this original image. Since a known digital image processing technique can be used for the process of extracting an object from a digital image, a detailed description thereof will be omitted here. For example, the following references are related to the object extraction method.

[0011] "Present and Future of Pattern Recognition-How Much Objects Can Be Recognized by Machines", Nikkei Electronics, January 27, 1975, p.137. "Image Feature Extraction and Recognition," IEICE Journal, 1976
November, Vol.59, No.11, p.1181.

FIG. 2B shows an original image 3 by the processing 10.
3 shows objects O1 to O4 extracted from.
Next, in processing 11, these objects O1 to O4
A rectangular area circumscribing is obtained. S1 shown in FIG.
S4 represents a rectangular area circumscribing the objects O1 to O4, respectively.

In process 12, for each of the rectangular areas S1 to S4 obtained in process 11, as shown in FIG. 2D, center points P1 to P4 are obtained. Then, the position of the block in which the digital watermark information is to be embedded is determined so that the obtained center points P1 to P4 match the central point of each block in which the digital watermark information is to be embedded. FIG. 2E shows blocks B1 to B in which the digital watermark information thus obtained is embedded.
4 is shown.

In process 13, the original image 3 and predetermined digital watermark information are input, and the digital watermark information is embedded at the positions of the blocks B1 to B4 on the original image 3 shown in FIG. Thereby, the digital watermark embedded image 4 is generated.

For this digital watermark embedded image 4,
For example, as shown in FIG. 3, it is assumed that an image in a dotted line portion is cut out by image editing and pasted to another image. When extracting digital watermark information from the cut-and-paste image 4 ′ of the digital watermark embedded image, the digital watermark reading processing device 2 performs the following processing.

First, the processing 20 shown in FIG.
An object is extracted from the cut-and-paste image 4 ′ of the digital watermark embedded image as shown in FIG. FIG. 4B shows the objects O1 ′ and O2 ′ extracted from the cut-and-paste image 4 ′ by the process 20.
Is shown.

Next, in a process 21, a rectangular area circumscribing these objects O1 'and O2' is obtained. FIG.
S1 'and S2' shown in (C) represent rectangular areas circumscribing the objects O1 'and O2', respectively.

In step 22, the center points P1 'and P2' are obtained for each of the rectangular areas S1 'and S2' obtained in step 21 as shown in FIG. Then, the position of the block from which the digital watermark information is read is determined so that the obtained center points P1 'and P2' match the center point of each block from which the digital watermark information is read. FIG. 4 (E)
Indicates the positions of the blocks B1 'and B2' in which the digital watermark information thus obtained is embedded.

In step 23, digital watermark information is read from the positions of blocks B1 'and B2' in the cut-and-paste image 4 'of the digital watermark embedded image. In the above example, the center point of the rectangular area circumscribing the object matches the center point of the block in which the digital watermark information is embedded.
Although the position of the block in which the digital watermark information is embedded is determined, the present invention is not limited to this. The extracted object and the block in which the digital watermark information is embedded have a predetermined specific positional relationship. The present invention can be implemented by determining the position of a block in which digital watermark information is embedded.

[0020]

As described above, according to the present invention,
Even if the digital image in which the digital watermark information is embedded is edited by cutting and pasting, the embedded digital watermark information can be reliably read from a specific position. In addition, the digital watermark information can be embedded only in a portion having a characteristic as an image and actually needing protection as a copyrighted work without embedding it in unnecessary portions such as a uniform background.

[Brief description of the drawings]

FIG. 1 is a schematic explanatory diagram of the present invention.

FIG. 2 is a diagram showing an example of a digital watermark embedding process according to the present invention.

FIG. 3 is a diagram illustrating an example of editing a digital watermark embedded image.

FIG. 4 is a diagram showing an example of a digital watermark reading process according to the present invention.

FIG. 5 is an explanatory diagram of a conventional technique.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Digital watermark embedding processing apparatus 2 Digital watermark reading processing apparatus 3 Original image 4 Digital watermark embedding image 10-13 Processing by digital watermark embedding processing apparatus 20-23 Processing by digital watermark reading processing apparatus

Claims (3)

[Claims] 1. A digital watermark embedding / reading processing method for embedding digital watermark information in a digital image and reading digital watermark information from the digital image, wherein the digital watermark information is embedded when the digital watermark information is embedded in the digital image. The process of analyzing an original image that has not been extracted and extracting an object in the image, and the block that embeds the object and the digital watermark information,
The method includes the steps of determining the position of a block in which digital watermark information is embedded so that the positional relationship conforms to a certain rule, and embedding the digital watermark information in the block. A process of analyzing an image including at least a part of a digital image in which digital watermark information is embedded, extracting an object in the image, and a block in which the object and the block for reading the digital watermark information are located according to a certain rule. A digital watermark embedding read processing method, comprising: determining a position of a block from which digital watermark information is to be read; and reading digital watermark information from the block. 2. A program storage medium storing a program for causing a computer to execute a process of embedding digital watermark information in a digital image, wherein an original image in which digital watermark information is not embedded is analyzed to extract objects in the image. To determine the position of the block in which the digital watermark information is to be embedded, and to embed the digital watermark information in the block so that the object and the block in which the digital watermark information is to be embedded have a positional relationship according to a certain rule. A digital watermark embedding processing program storage medium storing a program for realizing processing. 3. A program storage medium storing a program for causing a computer to execute a process of reading digital watermark information from a digital image, the program storage medium analyzing an image including at least a part of the digital image in which the digital watermark information is embedded, Processing to extract objects in the image;
Processing for determining the position of the block from which the digital watermark information is read such that the object and the block from which the digital watermark information is read have a positional relationship in accordance with a certain rule;
A program storage medium for storing a digital watermark reading processing program for realizing processing for reading digital watermark information from the block.