JPH11296661A - Image processor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To specify right information in an image by extracting the image of a prescribed area of an original image, converting the extracted image into invisible electronic watermark information and writing this information into another image where the visible electronic watermark information is written. SOLUTION: An image 7 in a prescribed area 5 of an original image 3-1 and position information on the image 7 are extracted (201). The image 7 is converted into invisible electronic watermark information 9 (202). Then an image 11 of right information etc., is overwritten in an area 5 of an image 3-2 as a visible electronic watermark (203) to generate an image 3-3. The right information is written in an area 5 of the image 3-3 together with information 9 embedded into the area 5 to obtain a prescribed image (204). Thus, its possible to insert and specify the right information in an image and also exclude the right information to keep the design property of the image.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image processing apparatus using a digital watermark.

[0002]

2. Description of the Related Art Recently, when a digital image or the like is transmitted on the Internet or the like, right information or the like may be inserted into the image. For example, in the displayed image,
Information indicating who owns the copyright of the image is inserted. Digital watermarking techniques for inserting rights information or the like into an image include a visible digital watermark in which the watermark is visible and an invisible digital watermark in which the watermark is invisible.

[0003]

By the way, when a visible digital watermark is inserted into an image, the design of the original image may be impaired, and the invisible digital watermark cannot specify the right information or the like.

[0004] The present invention has been made in view of such a problem, and an object thereof is to insert a right information in an image so as to specify the right information, and to remove the right information to remove a design of the image. It is an object of the present invention to provide an image processing apparatus capable of maintaining performance.

[0005]

In order to achieve the above-mentioned object, a first aspect of the present invention is a means for extracting an image of a predetermined area of an original image, and converting the image of the predetermined area into invisible digital watermark information. Means for writing another image in the predetermined area of the original image as a visible watermark, and means for writing the invisible watermark to the image on which the visible watermark has been written. Is an image processing apparatus.

According to a second aspect of the present invention, there is provided means for extracting the invisible digital watermark information from an image generated by the image processing apparatus according to the first aspect of the present invention to generate a visible image, and the predetermined area of the original image. Means for overwriting the visible image.

In a third aspect of the present invention, of the plurality of bit planes of the original image composed of a plurality of bit planes,
Means for selecting one bit plane, copying the contents of the first bit plane to the second bit plane of the two bit planes, and writing another image to the first bit plane as a visible digital watermark And an image processing apparatus.

According to a fourth aspect, there is provided a means for copying the contents of the second bit plane to the first bit plane of the original image generated by the image processing apparatus according to the third aspect. It is an image processing apparatus characterized by the following.

According to a fifth aspect of the present invention, there is provided means for extracting an image of a predetermined area of an original image, holding means for holding the image of the predetermined area, and displaying another image in the predetermined area of the original image. And a means for writing as a digital watermark.

According to a sixth aspect of the present invention, there is provided the fifth aspect of the present invention, wherein the means for extracting the image of the predetermined area from the holding means, and the predetermined image of the original image generated by the image processing apparatus according to the fifth aspect of the present invention. Means for overwriting an image of the predetermined area extracted from the holding means on the area of the image processing apparatus.

[0011]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a diagram illustrating a hardware configuration of an image processing apparatus according to an embodiment of the present invention. This image processing apparatus is realized by a personal computer 1 and a storage device 2.

Next, a processing procedure of the image processing apparatus will be described. 2 and 3 are flowcharts showing a processing procedure for inserting a visible digital watermark in the image processing apparatus.
4 to 8 are explanatory diagrams thereof.

FIG. 4 shows an original image 3-1. As shown in FIG. 5, the image 7 and the position information of a predetermined area 5 of the original image 3-1 are extracted (step 201), and the image 7 is invisible. It is converted to watermark information 9 (step 202). The invisible digital watermark information 9 is information for removing a visible digital watermark.

Next, as shown in FIG. 6, the image 11 such as the right information is overwritten on the area 5 of the image 3-2 as a visible digital watermark (step 203). FIG. 7 shows the image 3-3 generated in this way. In the area 5 of the image 3-3, the right information 5 is written. Then, as shown in FIG. 8, the invisible digital watermark information 9 is embedded (step 204), and an image 3-4 is obtained. At this time, the invisible digital watermark information 9 cannot be seen with the naked eye.

FIG. 3 is a flowchart showing the processing of steps 202 and 204. First, the image 7 is converted into a spectrum (step 301), and a specific spectrum is extracted (step 302). If the spectrum is a specific spectrum (step 303), the spectrum is handled as a target processing spectrum by the bit value of the insertion data. The amplitude of the spectrum is corrected (step 304). Then, the spectrum is inversely transformed into an image (step 305). It should be noted that the specific contents of the processing shown in FIG.
No. 93799. An image 3-4 as shown in FIG. 8 is provided on the Internet or the like.

FIGS. 9 and 10 are flowcharts showing a process of reproducing an image close to the original image by removing the visible digital watermark, and FIGS. 11 and 12 are diagrams showing the images in these processes. As shown in FIG. 11, invisible digital watermark information is extracted from the image 3-4 shown in FIG. 8 to generate a visible image 7 (step 901). Then, as shown in FIG. 12, the area 5 is overwritten with the image 7 (step 90).
2) Obtain an image 3-5 shown in FIG.

FIG. 10 is a flowchart showing the processing of step 901. The image 3-4 is converted into a spectrum (Step 1001), a specific spectrum is extracted (Step 1002), and a bit string is generated from the amplitude value of the spectrum (Step 1003).

The processing shown in FIG. 8 is disclosed in detail by the present applicant in the above-mentioned Japanese Patent Application No. 9-203799.

In FIG. 11, the right information is written in the area 5, the invisible digital watermark written in the image 3-4 is taken out to generate the image 7, and the image 7 is overwritten on the area 5. 13 is an original image 3-1.
Image.

That is, although the image 3-5 is different from the original image 3-1, the difference between the image 3-5 and the original image 3-1 cannot be identified with the naked eye. Therefore, the image 3-5 does not impair the design of the original image 3-1.

For example, when an image is sold on a network such as the Internet, as shown in FIG.
4 is sent free of charge, and an image 3-5 in which the visible digital watermark is removed from the sample image as shown in FIG. 13 is sent to a legitimate user who has paid the price.

As described above, in the present embodiment, by inserting a visible digital watermark into an image, it is possible to specify the right information regarding the image. Also, by removing the visible digital watermark as needed, the design of the original image can be maintained. Third parties who do not have a digital watermark extraction device corresponding to the digital watermark insertion device used for digital watermark insertion do not know the existence and contents of information for removing visible digital watermarks. However, it is difficult to illegally remove the visible digital watermark.

As a method for inserting an invisible digital watermark,
If you choose a method that is less resistant to image processing,
Since the information for removing the visible digital watermark is easily lost by performing the image processing, the possibility that the visible digital watermark is illegally removed is further reduced.

For an image into which a visible digital watermark has been inserted,
If it is desired to remove the visible digital watermark after performing some image processing, a method that inserts an invisible digital watermark that has high resistance to image processing may be selected.

Next, a second embodiment will be described. In the second embodiment, a multi-tone digital image is
This is an image processing device that inserts a value image as a visible digital watermark, and a multi-tone digital image is composed of a plurality of bit planes.

First, the insertion of a visible digital watermark will be described. FIG. 14 shows an original image 21. The original image 21 is shown in FIG.
As shown in the figure, for example, eight bit planes 23-
1, 23-3,..., 23-8. When the pixel value of a certain pixel is X, X = a1 * 128 + a2 * 64 + a3 * 32 + a4 * 1
6 + a5 * 8 + a6 * 4 + a7 * 2 + a8 * 1 a1 to a8 are represented as "0" or "1". The most significant bit plane 23-1 indicates the value of a1, the bit plane 23-2 indicates the value of a2, and similarly, the bit planes 23-3, 23-4,... Indicate the values of a3 to a8. .

In FIG. 15, the most significant bit plane 2
The contents of 3-1 are copied to the least significant bit plane 23-8. Although the information existing in the least significant bit plane 23-8 is lost, if the original image 21 has a sufficient number of gradations, the change in the least significant bit plane 23-8 cannot be identified with the naked eye. 14 can maintain the design of the original image 21 shown in FIG.

Next, as shown in FIG. 16, the image 27 as a visible digital watermark is overwritten on the area 25 of the most significant bit plane 23-1. The image 27 is an image indicating right information and the like.

As described above, image 2 is used as a visible digital watermark.
The image in which 7 is written is distributed as a sample to the Internet or the like.

Next, the removal of the visible digital watermark will be described. As shown in FIG. 17, the least significant bit plane 23
-1 is copied to the most significant bit plane, so that the first most significant bit plane 23-1 shown in FIG.
Is reproduced.

The bit plane into which the visible digital watermark is inserted need not be the highest bit plane. Since the visible digital watermark becomes less conspicuous as the bit plane becomes lower, the selection is made according to the required visual digital watermark appearance.

In the above embodiment, the content of the bit plane to be saved is replaced as it is with the content of the least significant bit plane. In order to make it difficult to be known to a third party, the arrangement of the bit string of the information to be saved may be changed, or the information may be encrypted and then written to the least significant bit plane. The save destination bit plane does not have to be the lowest. The higher the bit plane, the less likely it is to be lost by image processing.

The information for removing the visible digital watermark is stored in the least significant bit plane of the image, but this content is easily lost by the image processing. In this case, once the image processing is performed, there is a merit that it becomes more difficult to illegally remove the visible digital watermark thereafter.

Next, a third embodiment will be described. In the third embodiment, information of an original image at a position where a visible digital watermark is inserted is stored in the storage device 2. FIG. 18 shows an original image 31-1. As shown in FIG. 19, the image of the area 33 of the original image 31-1 is extracted and stored in the storage device 2. Then, as shown in FIG. 20, the image 35 indicating the right information and the like is displayed in the area 3 of the image 31-2.
3 to obtain an image 31-3. In this way,
The image 31-3 into which the visible digital watermark is inserted is distributed free of charge via the Internet or the like.

Next, the removal of the visible digital watermark will be described. The information of the area 33 stored in the storage device 2 is read, and the image 31-4 is obtained by overwriting the area 33 of the image 31-3 shown in FIG. Image 35 by overwriting
Are removed, and the original image 31-1 shown in FIG. 18 is restored.

[0036]

As described above in detail, according to the present invention, it is possible to insert the right information in the image so as to make it clear, and remove the right information to maintain the design of the image.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of hardware of an image processing apparatus.

FIG. 2 is a flowchart illustrating a process of inserting a visible digital watermark in the first embodiment.

FIG. 3 is a flowchart showing processing of step 202;

FIG. 4 is a diagram showing an image in a visible digital watermark insertion process;

FIG. 5 is a diagram showing an image in a process of inserting a visible digital watermark;

FIG. 6 is a diagram showing an image in a process of inserting a visible digital watermark;

FIG. 7 is a diagram showing an image in a process of inserting a visible digital watermark;

FIG. 8 is a diagram showing an image in a visible digital watermark insertion process.

FIG. 9 is a flowchart showing visible digital watermark removal processing;

FIG. 10 is a flowchart showing processing of step 901;

FIG. 11 is a diagram showing an image in a visible digital watermark removal process.

FIG. 12 is a diagram illustrating an image in a visible digital watermark removal process.

FIG. 13 is a diagram showing an image in a visible digital watermark removal process.

FIG. 14 is a diagram showing an image in a visible digital watermark insertion process according to the second embodiment;

FIG. 15 is a diagram showing an image in a visible digital watermark insertion process.

FIG. 16 is a diagram showing an image in a process of inserting a visible digital watermark.

FIG. 17 is a diagram showing an image in a visible digital watermark removal process.

FIG. 18 is a diagram illustrating an image in a process of inserting a visible digital watermark in the third embodiment.

FIG. 19 is a diagram showing an image in a visible digital watermark insertion process.

FIG. 20 is a diagram showing an image in a process of inserting a visible digital watermark;

FIG. 21 is a diagram showing an image in a visible digital watermark removal process.

[Explanation of symbols]

 1 ... Computer 2 ... Storage device 3 ... Original image 11 ... Image 21 ... Original image 23 ... Bit plane 27 ... Image 31 ... Original image 35 ... Image

Claims (7)

[Claims] A means for extracting an image in a predetermined area of the original image; a means for converting the image in the predetermined area into invisible digital watermark information; An image processing apparatus comprising: means for writing as a digital watermark; and means for writing the invisible digital watermark to an image to which the visible digital watermark has been written. 2. A means for extracting the invisible digital watermark information from an image generated by the image processing apparatus according to claim 1, and generating a visible image, and the visible image is provided in the predetermined area of the original image. An image processing apparatus, comprising: a unit for overwriting. 3. A plurality of bit planes of an original image composed of a plurality of bit planes, wherein two bit planes are selected, and a first bit plane is assigned to a second bit plane of the two bit planes. An image processing apparatus comprising: means for copying the contents of a plane; and means for writing another image as a visible digital watermark on the first bit plane. 4. The image processing apparatus according to claim 3, wherein the original image is a multi-tone image, and the another image is a binary image. 5. An image processing apparatus, comprising: means for copying the contents of the second bit plane into the first bit plane of the original image generated by the image processing apparatus according to claim 3. apparatus. 6. A means for extracting an image of a predetermined area of an original image; a holding means for holding an image of the predetermined area; and writing another image in the predetermined area of the original image as a visible digital watermark. And an image processing apparatus. 7. A means for retrieving an image of the predetermined area from the holding means according to claim 6, wherein the predetermined area of an original image generated by the image processing device is stored in the predetermined area from the holding means. Means for overwriting the extracted image of the predetermined area.