Image processing device, image processing method, and image processing program

Abstract

To efficiently embed information in electronic watermarks.MEANS FOR SOLVING THE PROBLEM: An image processing device has: a layer image generation unit configured to generate a plurality of layer images from image data having a plurality of layers; an embedding method determination unit configured to determine, according to the plurality of layer images and embedding information to be embedded in the image data, an embedding method for the embedding information into the layer images, to either a first embedding method that prioritizes information capacity or a second embedding method that prioritizes the accuracy of embedding and detection of the embedding information; and an embedding unit configured to embed the embedding information into the layer images using the embedding method determined by the embedding method determination unit.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to an image processing device, an image processing method, and an image processing program. [Background technology]

[0002] Conventionally, a technique for embedding digital watermark data in multiple layers of image data is known. Summary of the Invention [Problem to be solved by the invention]

[0003] The above-mentioned conventional techniques do not take into consideration the content of the image data or the amount of information to be embedded as a digital watermark, and therefore cannot be said to embed information efficiently.

[0004] The disclosed technology has been developed in view of the above circumstances, and aims to embed information efficiently in a digital watermark. [Means for solving the problem]

[0005] The disclosed technology is an image processing device having a layer image generation unit that generates multiple layer images from image data having multiple layers; an embedding method determination unit that determines the embedding method of the embedded information for the layer images to be either a first embedding method that prioritizes the amount of information, or a second embedding method that prioritizes the accuracy of embedding and detection of the embedded information, depending on the multiple layer images and the embedded information to be embedded in the image data; and an embedding unit that embeds the embedded information in the layer images using the embedding method determined by the embedding method determination unit. [Effects of the Invention]

[0006] The purpose is to embed information efficiently in digital watermarks. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a diagram illustrating a configuration of an image forming apparatus. [Figure 2] FIG. 10 is a diagram illustrating an overview of processing by an image compression unit. [Figure 3] 10 is a first flowchart illustrating processing by the image processing device. [Figure 4] 10 is a second flowchart illustrating the processing of the image processing device. [Figure 5] FIG. 10 is a diagram illustrating embedded information. [Figure 6] FIG. 1 is a diagram showing the structure of an image data file in TIFF format. [Figure 7] FIG. 10 is a diagram showing the structure of header data. [Figure 8] FIG. 1 is a diagram illustrating an IFD. [Figure 9] FIG. 10 is a diagram illustrating an IFD entry. [Figure 10] FIG. 2 is a diagram illustrating an example of an IFD according to the present embodiment. [Figure 11] 10A and 10B are diagrams illustrating a case where embedded information is embedded by a first embedding method. [Figure 12] 10A and 10B are diagrams illustrating a case where embedded information is embedded by a second embedding method. DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, an embodiment will be described with reference to the drawings: Fig. 1 is a diagram illustrating the configuration of an image forming apparatus.

[0009] First, the IN signals and OUT signals of each unit constituting the image forming apparatus 100 will be mainly explained using FIG. 1, and the internal details of each unit will be explained later as necessary.

[0010] The image forming apparatus 100 of this embodiment includes a scanner 1, an image processing apparatus 2, an HDD (Hard Disk Drive) 3, and a plotter 4.

[0011] The scanner 1 is a device that reads image data from an original document and sends the read image data (8-bit signals of r, g, and b after A / D conversion: linear reflectance) to the image processing device 2.

[0012] The image processing device 2 includes an image area separation unit 21 , a filter processing unit 22 , a data interface unit 23 , a color processing / UCR unit 24 , a printer correction unit 25 , and an image compression unit 52 .

[0013] Each of these units may be realized by a control device of the image processing device 2 reading and executing a program stored in a storage device of the image processing device 2.

[0014] The image area separation unit 21 separates text areas and picture areas using the image data (r, g, b) read by the scanner 1. The X signal output from the image area separation unit 21 is a 2-bit signal (text / non-text area signal, color / non-color area signal). The X signal is output to the HDD 3 via the filter processing unit 22 and the data interface unit 23 and stored therein.

[0015] The filter processing unit 22 applies a spatial filter to the image data (r, g, b) read by the scanner 1. The output (RGB signal, z signal) after the spatial filter processing by the filter processing unit 22 is output to and saved in the HDD 3 via the data interface unit 23. The z signal is a signal that represents an edge region. In other words, the z signal is edge information that represents an edge region.

[0016] In addition, the spatially filtered RGB signals are sent to a color processing / UCR unit 24 via a data interface unit 23. The color processing / UCR unit 24 converts each 8-bit RGB signal into an image signal (8 bits each of C, M, Y, and Bk) that serves as a control signal for the plotter 4 based on a predetermined conversion formula, and sends the image signal to a printer correction unit 25.

[0017] The printer correction unit 25 performs gamma correction and pseudo-halftoning that reflect the gradation characteristics of the plotter 4 on the C, M, Y, and Bk image signals, and outputs the signals to the plotter 4 .

[0018] The plotter 4, which is a transfer printing unit, transfers and prints the image signal output from the image processing device 2.

[0019] The image compression unit 52 generates layer image data for each layer from image data having multiple layers (plural layers) stored in the HDD 3, and embeds specified information in the layer image data as a digital watermark.

[0020] Digital watermarking is a technology that embeds relevant information in data such as images, videos, and audio in a form that is imperceptible to humans. In the following explanation, information embedded in layer image data by digital watermarking may be referred to as embedded information.

[0021] Specifically, the image compression unit 52 includes a layer image generation unit 53 , an embedding method determination unit 54 , and an embedding unit 55 .

[0022] The layer image generation unit 53 generates layer image data for each layer according to the characteristics of the image represented by the image data having multiple layers. The embedding method determination unit 54 determines the embedding method of the embedded information for the layer image data generated by the layer image generation unit 53.

[0023] The embedding unit 55 embeds the embedding information into the layer image data in the method determined by the embedding method determination unit 54. The embedding unit 55 also embeds information indicating the embedding method determined by the embedding method determination unit 54 into the layer image data together with the embedding information.

[0024] Next, an overview of the processing of the image compression unit 52 will be described with reference to Fig. 2. Fig. 2 is a diagram for explaining an overview of the processing of the image compression unit.

[0025] The image compression unit 52 of the image processing device 2 of this embodiment acquires image data from the scanner 1 (step S21). The image data acquired in step S21 may include image data having multiple layers. Specifically, the image data may be image data in TIFF format, etc.

[0026] Next, layer image data is generated from this image data by layer image generation unit 53 (step S22). Here, layer image generation unit 53 generates layer image data indicating a binary image (black character image) 41 consisting only of black character line drawings, layer image data indicating a binary image (color character image) 42 consisting only of character line drawings, layer image data indicating a multi-value image (character color image) 43 representing the color of the line drawing character, and layer image data indicating a multi-value image (background image) 44 representing a picture other than the line drawings.

[0027] Furthermore, in the image processing device 2 of this embodiment, the embedding unit 55 embeds embedded information into the binary image (black character image) 41 and the multilevel image (background image) 44 (steps S23 and S24). Specifically, the image processing device 2 embeds embedded information into the binary image (black character image) 41 by digital watermarking using edge information, and embeds embedded information into the multilevel image (background image) 44 by digital watermarking using frequency information, using the embedding unit 55.

[0028] In the following description, the embedded information embedded in the binary image (black character image) 41 will be referred to as first embedded information, and the embedded information embedded in the multilevel image (background image) 44 will be referred to as second embedded information. In addition, in the following description, the binary image (black character image) 41 into which the first embedded information is embedded will sometimes be referred to as a first layer image, and the multilevel image (background image) 44 into which the second embedded information is embedded will sometimes be referred to as a second layer image.

[0029] In addition, the image processing device 2 of this embodiment determines the embedding method for the first embedding information and the second embedding information for the binary image (black character image) 41 and the multi-value image (background image) 44 by the embedding method determination unit 54.

[0030] The following describes how the embedding method is determined by the embedding method determination unit 54. The embedding method determination unit 54 of this embodiment compares the data amount of the digital watermark that can be embedded in the image data with the data amount of the digital watermark that is to be embedded, and determines the embedding methods for the first embedding information and the second embedding information based on the comparison result.

[0031] In this embodiment, the data amount of a digital watermark that can be embedded in image data includes the number of characters that can be embedded in a binary image (black character image) 41 and the number of characters that can be embedded in a multi-value image (background image) 44. Also, in this embodiment, the data amount of a digital watermark to be embedded may be the number of characters of the specified embedding information.

[0032] The embedding method in this embodiment includes a first embedding method that prioritizes the amount of information and a second embedding method that prioritizes accuracy. More specifically, the first embedding method prioritizes increasing the amount of information embedded in image data. The second embedding method prioritizes the accuracy of embedding and detecting information into image data.

[0033] The first embedding method is a method in which the first embedding information and the second embedding information are different pieces of information, and by doing so, the first embedding method can increase the amount of information embedded in image data.

[0034] The second embedding method is a method in which the first embedding information and the second embedding information have the same content, and the second embedding method can increase resistance to tampering and improve the accuracy of tamper detection.

[0035] In this embodiment, the embedding method determination unit 54 determines the embedding method to be either the first embedding method or the second embedding method, and the embedding unit 55 embeds the first embedding information and the second embedding information into the first layer image and the second layer image, respectively, according to the determined embedding method.

[0036] The processing of the image compression unit 52 of the image processing device 2 of this embodiment will be further described below with reference to Fig. 3. Fig. 3 is a first flowchart illustrating the processing of the image processing device.

[0037] In the image processing device 2 of this embodiment, when the image compression unit 52 acquires image data read by the scanner 1 (step S301), the layer image generation unit 53 generates layer image data indicating a layer image (step S302). The layer image data generated here includes, as shown in Fig. 2, layer image data indicating a binary image (black character image) 41 consisting only of black character line drawings, layer image data indicating a binary image (color character image) 42 consisting only of character line drawings, layer image data indicating a multi-value image (character color image) 43 representing the color of the line drawing character, and layer image data indicating a multi-value image (background image) 44 representing a picture other than the line drawings.

[0038] Next, the image compression unit 52 acquires the embedded information and calculates the number of characters included in the embedded information (step S303).

[0039] The embedded information may be, for example, information indicating the date and time when the image data was acquired from the scanner 1 and the operator of the image forming apparatus 100, or information specifying the location where the image forming apparatus 100 is installed or the image forming apparatus 100 that was operated. Such embedded information may be acquired each time the image processing apparatus 2 performs the process of Fig. 3, or may be stored in advance in a storage device that the image processing apparatus 2 has.

[0040] In this embodiment, a priority may be assigned to each character string indicating an item of information included in the embedded information. In step S303, the image compression unit 52 acquires character strings indicating the items from the embedded information in accordance with the priority.

[0041] Next, the image compression unit 52 calculates the number of characters that can be embedded based on edge information of the black character region in the binary image (black character image) 41 (step S304). Next, the image compression unit 52 calculates the number of characters that can be embedded based on frequency information in the background image region of the multi-value image (background image) 44 (step S305).

[0042] Next, the image compression unit 52 determines the embedding method by the embedding method determination unit 54 (step S306).

[0043] The following describes the processing of the embedding method determination unit 54. The embedding method determination unit 54 of this embodiment determines the embedding method based on the number of characters included in the character string acquired as embedding information and the number of embeddable characters calculated in steps S304 and S305. In other words, the embedding method determination unit 54 determines the embedding method to be either the first embedding method or the second embedding method depending on the breakdown of the image data and the characters to be embedded.

[0044] Specifically, for example, the embedding method determination unit 54 may determine the embedding method as the first embedding method when the following condition 1 is satisfied, and may determine the embedding method as the second embedding method when the following condition 2 is satisfied.

[0045] (Condition 1) Number of characters in the embedded information < Number of characters that can be embedded x 2 (Condition 2) Number of characters in the embedded information ≥ Number of characters that can be embedded × 2 In other words, if the number of characters in the embedded information is less than twice the number of characters that can be embedded, the embedding method determination unit 54 may adopt an embedding method that prioritizes increasing the amount of information, and if the number of characters in the embedded information is twice or more the number of characters that can be embedded, the embedding method determination unit 54 may adopt a second embedding method that prioritizes improving resistance to tampering and the accuracy of tamper detection.

[0046] The number of characters that can be embedded here may be either the number of characters calculated in step S304 or the number of characters calculated in step S305, or may be the sum of the number of characters calculated in step S304 and the number of characters calculated in step S305.

[0047] In step S305, if the embedding method is determined to be the first embedding method, the embedding unit 55 identifies the first embedding information to be embedded in the binary image (black character image) 41 according to the first embedding method (step S307).

[0048] Here, the embedding unit 55 specifies the first embedding information in accordance with the priority order, starting from the character string with the highest priority among the character strings in each item of the embedding information, based on the number of characters that can be embedded in the binary image (black character image) 41 calculated in step S304. Note that if it is not possible to embed all the character strings in each item, embedding may be omitted.

[0049] Next, the embedding unit 55 specifies the second embedding information in accordance with the priority order following from step S307 for the character string of each item based on the number of characters that can be embedded based on the multi-valued image (background image) 44 calculated in step S305 (step S308), and proceeds to step S311, which will be described later. Note that in step S308, if it is not possible to embed all the character strings in each item, embedding may be omitted.

[0050] In step S306, if the second embedding method is determined as the embedding method, the embedding unit 55 specifies the first embedding information to be embedded in the binary image (black character image) 41 according to the second embedding method (step S309). The process in step S309 is the same as the process in step S307, and therefore a description thereof will be omitted.

[0051] Next, the embedding unit 55 identifies the second embedding information in accordance with the priority order, starting with the string with the highest priority among the strings of each item in the embedding information, based on the number of characters that can be embedded based on the multi-value image (background image) 44 (step S310), and proceeds to step S311, which will be described later.

[0052] Next, the embedding unit 55 of the image compression unit 52 embeds the first embedding information and the second embedding information (step S311). Details of the process of step S311 will be described later.

[0053] 2, the embedding method is determined according to Condition 1 and Condition 2, but this is not limiting. The method for determining the embedding method is not limited to the example shown in FIG. 3, and may be set arbitrarily. Specifically, for example, the embedding method may be determined by the operation of the operation unit of the image forming apparatus 100, which includes the image processing apparatus 2, by the user of the image forming apparatus 100.

[0054] Next, the processing of the image compression unit 52 will be further described with reference to Fig. 4. Fig. 4 is a second flowchart illustrating the processing of the image processing device. Fig. 4 shows details of the processing of step S311 in Fig. 3.

[0055] In the image processing device 2 of this embodiment, the embedding unit 55 acquires each layer image data generated in step S302 of FIG. 3 (steps S401 to S404), and compresses each layer image data.

[0056] 3 in the black character region of the binary image (black character image) 41 indicated by the layer image data acquired in step S401, using edge information (step S405). Subsequently, the image compression unit 52 performs binary Modified Modified Read (MMR) compression on the layer image data indicating the binary image (black character image) 41 in which the first embedding information has been embedded (step S406), and proceeds to step S414, which will be described later.

[0057] Furthermore, the image compression unit 52 performs MMR compression on the layer image data indicating the binary image (color character image) 42 acquired in step S402 (step S407), and the process proceeds to step S414, which will be described later.

[0058] Furthermore, the image compression unit 52 performs JPEG compression on the layer image data indicating the multi-valued image (text color image) 43 acquired in step S403 (step S408), and the process proceeds to step S414, which will be described later.

[0059] Furthermore, the image compression unit 52 embeds second embedding information in the background image area during the process of performing JPEG compression on the layer image data indicating the multi-valued image (background image) 44 acquired in step S404.

[0060] Specifically, the image compression unit 52 converts the RGB color values of the multi-value image (background image) 44 acquired in step S404 into the YCbCr color space (step S409), then performs a DCT (discrete cosine transform) (step S410), and quantizes the image (step S411).

[0061] Next, the image compression unit 52 embeds the second embedding information into the quantized layer image data using the discrete Fourier transform by the embedding unit 55 (step S412). Next, the image compression unit 52 entropy encodes the layer image data in which the second embedding information has been embedded (step S413), and proceeds to step S414, which will be described later.

[0062] The image compression unit 52 causes the embedding unit 55 to embed information indicating the embedding method determined in step S306 in FIG. 3 into the image data acquired in step S301 in FIG. 3 (step S414), and ends the process.

[0063] In this embodiment, the value indicating the embedding method determined by the embedding method determination unit 54 may be included as part of the first embedding information and the second embedding information. Also, in this embodiment, the value indicating the embedding method determined by the embedding method determination unit 54 may be embedded in a text portion such as header data of the image data.

[0064] In this embodiment, by embedding information indicating the embedding method of the embedded information in the image data, it is possible to prevent the embedded information from being misrecognized when reading image data in which the embedded information is embedded, and to allow the embedded information to be analyzed appropriately.

[0065] Next, the embedding of information indicating the embedding method of the embedded information will be described with reference to FIGS.

[0066] Fig. 5 is a diagram illustrating the embedding information, which shows a case where the embedding information includes identification information indicating the embedding method.

[0067] In the example of Fig. 5, the identification information indicating the first embedding method is "&", and the identification information indicating the second embedding method is "@". These identification information are embedded in the image data together with the embedding information. Note that the identification information indicating the embedding method may be set arbitrarily, and the information shown in Fig. 5 may be stored in a storage device of the image processing device 2, etc.

[0068] In the example of Fig. 5, when an image in which embedded information is embedded is read, if the embedded information contains an identification symbol "&", it is detected that the embedded information was embedded using the first embedding method. Also, in the example of Fig. 5, if the embedded information contains an identification symbol "@", it is detected that the embedded information was embedded using the second embedding method.

[0069] Next, a case where information indicating the embedding method is included in header data included in image data into which embedded information is embedded will be described. The image data into which embedded information is embedded is data read by the scanner 1, and may be an image data file in TIFF format, etc.

[0070] An image data file in TIFF format includes header data, image data, etc. Fig. 6 is a diagram showing the structure of an image data file in TIFF format.

[0071] As shown in FIG. 6, an image data file in TIFF format includes header data, image data, an IFD (Image File Directory), and related data.

[0072] Figure 7 shows the structure of header data. The header data included in an image data file is used to identify whether the image data is a TIFF format file. The header data stores information indicating whether the data included in the image data file is big endian or little endian, the version number of the TIFF file, and an offset indicating the IFD.

[0073] Figure 8 is a diagram explaining the IFD. As shown in Figure 8, the IFD contains various information for indicating the image configuration and is composed of the number of IFD entries, IFD entries (multiple), and an IFD pointer. The number of IFD entries is set up in the number indicated by the number of IFD entries. If there are multiple IFD areas, the IFD pointer points to the next IFD pointer.

[0074] Figure 9 is a diagram explaining IFD entries. An IFD entry consists of an identification tag, a data type code, the number of data, and an offset to the data. The value of the identification tag is a code that indicates the type of information indicated by the IFD. The information type includes the vertical and horizontal sizes, number of colors, and number of bits required to form image data. The value of the data type code is a value that encodes the data type of the information by type. The value of the number of data is the amount of the data type of the aforementioned information. The offset to the data is the offset to the data related to the aforementioned IFD.

[0075] Fig. 10 is a diagram showing an example of an IFD in this embodiment. In the example shown in Fig. 10, the value of the identification tag is set to a value indicating the embedding method of the embedded information. In this embodiment, for example, a BYTE-type data repository is prepared, and the value of the identification tag is set to a value indicating the embedding method determined by the embedding method determination unit 54 from among a first embedding method that prioritizes the amount of information (number of characters) and a second embedding method that prioritizes accuracy and robustness.

[0076] FIG. 11 is a diagram illustrating a case where embedding information is embedded by the first embedding method.

[0077] FIG. 11 shows a case where first embedding information and second embedding information are embedded in a binary image (black character image) 41 and a multi-valued image (background image) 44, respectively, using a first embedding method that prioritizes increasing the amount of information.

[0078] In this case, the first embedding information 11a embedded in the binary image (black character image) 41 and the second embedding information 11b embedded in the multi-value image (background image) 44 are different pieces of information.

[0079] Specifically, in Figure 11, the first embedded information 11a is information indicating the date and time when the scanner 1 acquired the image data and the operator who operated the image forming device 100, and the second embedded information 11b is information indicating the installation location of the image forming device 100 and information that identifies the image forming device 100.

[0080] In this embodiment, by making the first embedding information and the second embedding information different from each other, it is possible to increase the amount of embedding information embedded in image data.

[0081] FIG. 12 is a diagram illustrating a case where embedding information is embedded by the second embedding method.

[0082] FIG. 12 shows a case where first embedding information and second embedding information are embedded in a binary image (black character image) 41 and a multi-valued image (background image) 44, respectively, using a second embedding method that prioritizes improving resistance to tampering and accuracy in detecting tampering.

[0083] In this case, the first embedded information 11a embedded in the binary image (black character image) 41 and the second embedded information 11b' embedded in the multi-valued image (background image) 44 contain the same content.

[0084] Specifically, in FIG. 12, the first embedded information 11a and the second embedded information 11b' are information indicating the date and time when the scanner 1 acquired the image data and the operator who operated the image forming device 100.

[0085] In the example of Fig. 12, by making the first embedded information 11a and the second embedded information 11b' similar in content, even if there is a small amount of black text and detection of the first embedded information 11a fails, the second embedded information 11b' can be detected. Also, in the example of Fig. 12, even if the second embedded information 11b' is lost due to rotation, scaling, or other editing of the image data, the first embedded information 11a can be detected.

[0086] In this embodiment, the method for embedding information using a digital watermark is selected from a first embedding method that prioritizes increasing the amount of information, and a second embedding method that prioritizes the accuracy of embedding and detecting the embedded information.

[0087] Therefore, according to this embodiment, it is possible to embed information into image data in a manner suited to the application, and to embed information efficiently in a digital watermark.

[0088] For example, aspects of the present invention are as follows. <1> a layer image generating unit that generates a plurality of layer images from image data having a plurality of layers; an embedding method determination unit that determines, in accordance with the plurality of layer images and the embedding information to be embedded in the image data, whether the embedding method for the layer images is a first embedding method that prioritizes the amount of information or a second embedding method that prioritizes the accuracy of embedding and detection of the embedding information; an embedding unit that embeds the embedded information in the layer image using the embedding method determined by the embedding method determination unit. <2> a layer image generating unit that generates a plurality of layer images from image data having a plurality of layers; an embedding method determination unit that selects a method for embedding the information to be embedded in the image data from a first embedding method that prioritizes the amount of information or a second embedding method that prioritizes the accuracy of embedding and detecting the information; an embedding unit that embeds the embedded information in the layer image using the embedding method determined by the embedding method determination unit. <3> the embedding unit includes information indicating the embedding method determined by the embedding method determination unit in the embedding information. <1> or <2> The image processing device described above. <4> the embedding unit includes information indicating the embedding method determined by the embedding method determination unit in header data included in the image data. <1> or <2> The image processing device described above. <5> The first embedding method is: First embedding information embedded in a first layer included in the plurality of layers and second embedding information embedded in a second layer included in the plurality of layers are information of the same content; The second embedding method is: The first embedding information and the second embedding information are different in content. <1> ~ <4> 10. The image processing device according to claim 1, wherein: <6> An image processing method using an image processing device, the image processing device comprising: generating a plurality of layer images from image data having a plurality of layers; determining a method for embedding the information into the layer image according to the image data and the information to be embedded in the image data, to be either a first method for embedding the information in the layer image that prioritizes the amount of information, or a second method for embedding the information in the layer image that prioritizes the accuracy of embedding and detecting the information; The image processing method further comprises embedding the embedded information in the layer image using the embedding method determined by the embedding method determination unit. <7> generating a plurality of layer images from image data having a plurality of layers; determining a method for embedding the information into the layer image according to the image data and the information to be embedded in the image data, to be either a first method for embedding the information in the layer image that prioritizes the amount of information, or a second method for embedding the information in the layer image that prioritizes the accuracy of embedding and detecting the information; an image processing program that causes an image processing device to execute a process of embedding the embedding information in the layer image using the embedding method determined by the embedding method determination unit;

[0089] Although the present invention has been described above based on the embodiments, the present invention is not limited to the requirements shown in the above embodiments. These requirements can be changed without departing from the spirit of the present invention, and can be appropriately determined depending on the application form. [Explanation of symbols]

[0090] 1. Scanner 2. Image processing device 52 Image Compression Unit 53 Layer image generation unit 54 Embedding method determination unit 55 Embedded part 100 Image forming device [Prior art documents] [Patent documents]

[0091] [Patent Document 1] Japanese Patent Application Laid-Open No. 2002-247339

Claims

1. a layer image generating unit that generates a plurality of layer images from image data having a plurality of layers; an embedding method determination unit that determines, in accordance with the plurality of layer images and the embedding information to be embedded in the image data, whether the embedding method for the layer images is a first embedding method that prioritizes the amount of information or a second embedding method that prioritizes the accuracy of embedding and detection of the embedding information; an embedding unit that embeds the embedded information in the layer image using the embedding method determined by the embedding method determination unit.

2. a layer image generating unit that generates a plurality of layer images from image data having a plurality of layers; an embedding method determination unit that selects a method for embedding the information to be embedded in the image data from a first embedding method that prioritizes the amount of information or a second embedding method that prioritizes the accuracy of embedding and detecting the information; an embedding unit that embeds the embedded information in the layer image using the embedding method determined by the embedding method determination unit.

3. The image processing device according to claim 1 , wherein the embedding unit includes information indicating the embedding method determined by the embedding method determination unit in the embedding information.

4. 3. The image processing device according to claim 1, wherein the embedding unit includes information indicating the embedding method determined by the embedding method determination unit in header data included in the image data.

5. The first embedding method is: First embedding information embedded in a first layer included in the plurality of layers and second embedding information embedded in a second layer included in the plurality of layers are information of the same content; The second embedding method is:

3. The image processing device according to claim 1, wherein the first embedded information and the second embedded information are different in content.

6. An image processing method using an image processing device, the image processing device comprising: generating a plurality of layer images from image data having a plurality of layers; determining a method for embedding the information into the layer image according to the image data and the information to be embedded in the image data, to be either a first method for embedding the information in the layer image that prioritizes the amount of information, or a second method for embedding the information in the layer image that prioritizes the accuracy of embedding and detecting the information; The image processing method further comprises embedding the embedded information in the layer image using the embedding method determined by the embedding method determination unit.

7. generating a plurality of layer images from image data having a plurality of layers; determining a method for embedding the information into the layer image according to the image data and the information to be embedded in the image data, to be either a first method for embedding the information in the layer image that prioritizes the amount of information, or a second method for embedding the information in the layer image that prioritizes the accuracy of embedding and detecting the information; an image processing program that causes an image processing device to execute a process of embedding the embedding information in the layer image using the embedding method determined by the embedding method determination unit;

Images