JP6362191B1 - Image processing system, image processing apparatus, image processing method, and program - Google Patents

Abstract

To embed information without degrading image quality.
An image processing system according to an embodiment of the present invention includes a first image processing device and a second image processing device, and the first image processing device uses palette information that defines color information. Input means for inputting image data including a first palette table in which a plurality of associated index values are arranged according to a predetermined rule; and the index values are rearranged based on an embedded data string, and the first palette table is Rearrangement means for converting to the second palette table; and conversion means for converting the index value of the first palette table associated with each pixel constituting the image data to the index value of the second palette table. And output means for outputting converted image data including the second palette table.
[Selection] Figure 1

Description

  The present invention relates to an image processing system, an image processing apparatus, an image processing method, and a program for embedding information in a digital image.

  In recent years, from the viewpoint of protection and use of digital content, digital watermarking technology that embeds information such as meta information such as image right information and additional messages in addition to image data is used for digital images. Patent Document 1 describes a method of embedding information while suppressing deterioration in image quality by rewriting the least significant bit of each data of the color palette.

JP 2004-88565 A

  However, in the method described in Patent Document 1, image data is inevitably deteriorated because image data is modified even with the least significant bit.

  SUMMARY An advantage of some aspects of the invention is that it provides an image processing system, an image processing apparatus, an image processing method, and a program capable of embedding information without causing deterioration in image quality. And

  According to an aspect of the present invention, there is provided an image processing system including a first image processing device and a second image processing device, wherein the first image processing device is associated with palette information defining color information. Input means for inputting image data including a first palette table in which a plurality of index values are arranged according to a predetermined rule; and the index values are rearranged based on an embedded data string, and the first palette table is converted into a second Rearrangement means for converting into a palette table; conversion means for converting the index value of the first palette table associated with each pixel constituting the image data into the index value of the second palette table; Output means for outputting converted image data including the second palette table, and the second image processing apparatus includes An image comprising: means for inputting image data; and means for taking out the embedded data string based on the order of the index values in the second palette table of the converted image data and the predetermined rule A processing system is provided.

  According to another aspect of the present invention, an input means for inputting image data including a first palette table in which a plurality of index values associated with palette information defining color information are arranged according to a predetermined rule, and an embedded data string Reordering means for reordering the index values and converting the first pallet table into a second pallet table, and the first pallet table associated with each pixel constituting the image data. An image processing apparatus is provided, comprising: conversion means for converting an index value into the index value of the second palette table; and output means for outputting converted image data including the second palette table. The

  According to still another aspect of the present invention, in image data including a first palette table in which a plurality of index values associated with palette information defining color information are arranged in a predetermined rule, the image data is based on an embedded data string. By rearranging the index values, the first palette table is converted into a second palette table, and the index value of the first palette table associated with each pixel constituting the image data is changed to a second palette table. The embedded data string is extracted based on input means for inputting the converted image data converted into the index value of the palette table, the order of the index values in the second palette table of the converted image data, and the predetermined rule. And an image processing apparatus characterized by comprising an extraction means. .

  According to still another aspect of the present invention, a step of inputting image data including a first palette table in which a plurality of index values associated with palette information defining color information are arranged according to a predetermined rule, and an embedded data string Rearranging the index values based on the first palette table, converting the first palette table into a second palette table, and the index values of the first palette table associated with each pixel constituting the image data Is converted to the index value of the second palette table, and converted image data including the second palette table is output. An image processing method is provided.

  According to still another aspect of the present invention, in image data including a first palette table in which a plurality of index values associated with palette information defining color information are arranged in a predetermined rule, the image data is based on an embedded data string. By rearranging the index values, the first palette table is converted into a second palette table, and the index value of the first palette table associated with each pixel constituting the image data is changed to a second palette table. A step of inputting the converted image data converted into the index value of the palette table; and a step of extracting the embedded data string based on the order of the index values in the second palette table of the converted image data and the predetermined rule An image processing method is provided.

  According to still another aspect of the present invention, a step of inputting image data including a first palette table in which a plurality of index values associated with palette information defining color information are arranged according to a predetermined rule, and an embedded data string Rearranging the index values based on the first palette table, converting the first palette table into a second palette table, and the index values of the first palette table associated with each pixel constituting the image data Is provided for causing a computer to execute an image processing method including the step of converting the image data into the index value of the second palette table and the step of outputting converted image data including the second palette table. .

  According to the present invention, it is possible to embed information in an image without causing deterioration in image quality.

1 is a block diagram of an image processing system in a first embodiment. 1 is a block diagram of an image processing apparatus according to a first embodiment. It is a block diagram of the 1st image processing device in a 1st embodiment. It is a block diagram of the 2nd image processing device in a 1st embodiment. It is a figure for demonstrating the rearrangement pattern of the palette information in 1st Embodiment. It is a figure for demonstrating the information content which can be embedded in 1st Embodiment. It is a flowchart showing the data embedding process in 1st Embodiment. It is a figure for demonstrating the rearrangement procedure of the palette information in the data embedding process of 1st Embodiment. It is a flowchart showing the data extraction process in 1st Embodiment. It is a figure for demonstrating the rearrangement procedure of the palette information of the data extraction process in 1st Embodiment. It is a figure for demonstrating the correspondence of the rearrangement pattern of palette information in 1st Embodiment, Lehmer code, and a factorial number. It is a figure showing the palette information in a 1st embodiment, an embedded data sequence, and a palette table after rearrangement. It is a block diagram of the image processing system in 2nd Embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(First embodiment)
FIG. 1 is a block diagram of an image processing system according to this embodiment. The image processing system includes an image processing apparatus 1 that outputs converted image data by embedding information in the image data, and an image processing apparatus 2 that extracts information embedded in the converted image data. An image processing apparatus (first image processing apparatus) 1 and an image processing apparatus (second image processing apparatus) 2 can be connected to each other via a communication line 3. The communication line 3 can typically be a WAN (Wide Area Network) such as the Internet, but may be a LAN (Local Area Network), and may be wired or wireless. Further, the converted image data may be transferred from the image processing apparatus 1 to the image processing apparatus 2 using an external storage medium such as a memory card, an optical disk, or a magnetic disk instead of the communication line 3.

  The image processing apparatus 1 is, for example, a content server, and embeds data such as copyright information, signature information, and a message in the image data as a so-called digital watermark, and outputs converted image data. The image processing device 2 is a user's computer terminal, portable terminal, media playback device, or the like, and can take out digital watermark information embedded in the converted image data, and can restrict image reproduction, duplication, and recording according to the digital watermark information.

  FIG. 2 is a hardware block diagram of the image processing apparatuses 1 and 2. The image processing apparatuses 1 and 2 include a CPU (Central Processing Unit) 11, a bus 12, a RAM (Random Access Memory) 13, a storage 14, a keyboard 15, a display 16, and an interface 17. The CPU 11 embeds or extracts a digital watermark from the image data based on a predetermined application program, and controls the operation of each device connected to the bus 12. The RAM 13 is used as a work area for the operation of the CPU 11 and can temporarily hold application programs and image data. The storage 14 is a storage device that can hold application programs and image data, such as a nonvolatile memory and a hard disk device. The keyboard 15 sends characters and numbers input by the user to the bus as digital data. The display 16 includes a liquid crystal display device, an organic light emitting device, and the like, and can display image data. The interface 17 can be connected to the communication line 3 and functions as image data input means or output means.

  3 and 4 are functional block diagrams of the image processing apparatus according to the present embodiment. FIG. 3 shows an outline of data embedding processing by the image processing apparatus 1, and FIG. An overview is shown.

  In FIG. 3, the image processing apparatus 1 includes a rearrangement unit (rearrangement unit) 101 and a conversion unit (conversion unit) 102, and generates converted image data in which an embedded data string d is embedded in image data. In the present embodiment, the image data is described according to a so-called palette image format, and may include pixel data Px and palette information Pa. Examples of the format of the palette image include GIF (Graphics Interchange Format) and PNG (Portable Network Graphics), but the present invention is not limited to these formats. The palette information Pa defines color information that is a combination of the three primary colors of light (R (Red), G (Green), and B (Blue)). The palette information Pa includes, for example, 256 pieces represented by integers from 0 to 255. Is associated with an index value. The plurality of palette information Pa and the index value constitute a palette table (color table). In this example, the maximum number of colors in the palette image is 256 colors. Each of the plurality of pixel data Px can represent a color defined by the palette information Pa by an index value. The embedded data string d may be, for example, copyright information, signature information, a message, etc., but may be other information.

  The rearrangement unit 101 rearranges the palette information Pa in the first palette table based on the input embedded data string d, and generates a second palette table having the palette information Pa ′. Rearrangement from the palette information Pa to the palette information Pa ′ can be performed by rearranging the index values associated with the palette information Pa. Accordingly, in the following description, the rearrangement of index values may be referred to as the rearrangement of palette information. The second pallet table includes the same pallet information as the first pallet table, but the arrangement order of the pallet information Pa 'is different from the arrangement order of the pallet information Pa. The order of the index values in the rearranged palette information Pa 'corresponds to the embedded data string d.

  The conversion unit 102 converts the index value of the pixel data Px based on the palette information Pa and the palette information Pa ′, and generates pixel data Px ′. The converted image data includes a second palette table having palette information Pa ′ and pixel data Px ′. The rearranged second palette table includes information of the embedded data string d. In the present embodiment, the image reproduced by the converted image data is the same as the image reproduced by the image data, and image quality deterioration due to the embedded data string d does not occur.

  In FIG. 4, the image processing apparatus 2 includes a rearrangement unit (extraction means) 201. The rearrangement unit 201 generates an embedded data string d from the order of the index values associated with the palette information Pa ′ in the second palette table. Take out. The image processing apparatus 2 can determine the presence / absence of alteration of the converted image data, copyright information, etc. according to the information of the extracted embedded data string d.

  FIG. 5 is a diagram for explaining a pallet information rearrangement pattern in the present embodiment, and shows the correspondence between n elements, Lehmer code, and factorial number. In general, there are n factorial (n!) Types of combinations for rearranging n unique elements. Each rearrangement pattern of this combination can be uniquely associated with the Lehmer code and its factorial number. For example, when n = 4, the sort pattern type is 4! = 24 ways, represented as shown in FIG.

  Here, b (1), b (2),..., B (n) of Lehmer code, when permutations a (1), a (2),. b (i) is defined as the number of a (j) that satisfies a (i)> a (j) in the range of i + 1 ≦ j ≦ n. The factorial number is a sum obtained by multiplying each digit represented by b (i) by the factorial when permutations b (1), b (2),..., B (n) exist. “B (1) × (n−1)! + B (2) × (n−2)! +... + B (n−1) × 1! + B (n) × 0!”

  As shown in FIG. 6, log 2 (n!) Bits of information can be embedded by rearranging n elements into a significant pattern. Here, log2 (x) represents a logarithm with 2 as the base. For example, when n = 13, 32-bit information can be embedded by rearranging 13 elements into a significant specific pattern.

  In the palette table of image data, the index value is associated with palette information that is color information (RGB) of an arbitrary pixel. Therefore, as long as the correspondence between the pixel data and the palette information Pa in the palette table is maintained, the arrangement order of the palette information in the palette table can be arbitrarily determined.

  Specific information can be embedded by dividing the palette table into a plurality of groups and rearranging the palette information Pa for each group. For example, if n pallet information Pa is included in one group, the amount of information that can be embedded in one group is M = [log2 (n!)] Bits. Here, [x] represents a Gaussian symbol and represents the maximum integer not exceeding x. When the total number of palette information Pa in the palette table is “256”, the number of groups is G = [256 ÷ n], and the amount of information that can be embedded in the entire palette table is G × M = [log2 (n!)]. × [256 ÷ n] bits.

  Next, the operation of the image processing system in the present embodiment will be described in detail with reference to FIGS. In the following description, the number of pallet information Pa of one group is “13”, and the number of pallet information Pa of the entire pallet table is “256”, but the present invention is not necessarily limited to these numbers. . When the number of pallet information Pa of one group is “13”, the information amount M that can be embedded in the pallet information Pa of one group is [log2 (13!)] = 32 bits (see FIG. 6). The number of groups that can be used for embedding is [256 ÷ 13] = 19. Therefore, the amount of information that can be embedded is 19 × 32 bits = 608 bits = 76 bytes.

  FIG. 7 is a flowchart showing the data embedding process in this embodiment, and FIG. 8 is a diagram for explaining the rearrangement procedure of the palette information Pa in the data embedding process. Here, the image data has 256 pieces of palette information Pa indicated by index values Pa (0) to Pa (255), and a plurality of pixel data Px of a two-dimensional matrix, and information to be embedded is 76 embedded data strings. d (0), d (1),..., d (75). Hereinafter, the palette information Pa corresponding to the index values Pa (0) to Pa (255) will be collectively referred to as palette information Pa (0) to Pa (255). The image processing apparatus 1 divides 256 pieces of palette information Pa (0) to Pa (255) into a plurality of groups each including 13 pieces of palette information Pa, and rearranges the palette information Pa within each group. .

  First, the CPU 11 of the image processing apparatus 1 reads the original image data stored in the storage 14, and determines whether there are 13 or more pallet information items that have not been rearranged in the pallet table (step S11). If the number of palette information Pa that has not been rearranged is less than 13 (NO in step S11), the image processing apparatus 1 ends the rearrangement process.

  When there are 13 or more pallet information items that have not been rearranged (YES in step S11), the image processing apparatus 1 obtains 13 index values Pa (0) to Pa (12) from the top of the first pallet table. It takes out as one group (step S12). As shown in FIG. 8, the palette information Pa (0) associated with the index value Pa (0) indicates the value of RGB (0,0,0), and the palette associated with the index value Pa (1). Information Pa (1) indicates a value of RGB (0, 0, 64). The palette information Pa (12) associated with the index value Pa (12) indicates RGB (128, 0, 128).

  Next, the image processing apparatus 1 rearranges the retrieved index values Pa (0) to Pa (12) according to a predetermined rule (step S13). A predetermined rule is shared in advance between the image processing apparatus 1 and the image processing apparatus 2. The predetermined rule can be arbitrarily determined. For example, the index value Pa may be rearranged in the ascending order or descending order of the color components of the palette information Pa, and the first ascending order of the color components of the palette information Pa and the first descending order. The index values may be rearranged in the second ascending order, the second descending order, the third ascending order, and the third descending order. Here, as shown in FIG. 8, an example will be described in which the index value Pa is rearranged in ascending order of the R, G, and B color components. The palette information Pa (0) to Pa (12) of the index values Pa (0) to Pa (12) extracted in step S12 is (0,0,0), (0,0,64), (0, 64,0), (0,64,64), (64,0,0), (64,0,64), (64,64,0), (64,64,64), (0,0, 128), (0, 128, 0), (0, 128, 128), (128, 0, 0), and (128, 0, 128) color information. In step S13, the palette information Pa (0) to Pa (12) of the index values Pa (0) to Pa (12) is rearranged in the ascending order of R, ascending order of G, and ascending order of B in step S13. , 0,0), (0,0,64), (0,0,128), (0,64,0), (0,64,64), (0,128,0), (0,128 , 128), (64, 0, 0), (64, 0, 64), (64, 64, 0), (64, 64, 64), (128, 0, 0), (128, 0, 128) ).

  The image processing apparatus 1 extracts the leading 4-byte embedded data strings d (0), d (1), d (2), and d (3) from the embedded data string d (step S14). Here, it is assumed that the extracted embedded data string d is “1000 — 0000 — 0000 — 0000 — 0000 — 0000 — 0000 — 0000” expressed in 32 bits. The CPU 11 regards the 32-bit embedded data string d as a factorial number, calculates the corresponding Lehmer code, and obtains a rearrangement pattern corresponding to the Lehmer code (step S15). The above-described embedded data string is represented by the decimal number “2,147,483,648”, and this value is “4 × 12! + 5 × 11! + 8 × 10! +7” as shown in FIG. X9! + 8x8! + 0x7! + 0x6! + 1x5! + 0x4! + 1x3! + 1x2! + 0x1! + 0x0! " The Lehmer code “4, 5, 8, 7, 8, 0, 0, 1, 0, 1, 1, 0, 0” is obtained from the coefficient in the factorial number. Further, the rearrangement pattern “4, 6, 10, 9, 12, 0, 1, 3, 2, 7, 8, 5, 11” corresponding to the Lehmer code is obtained. In this way, 13 number sequences “0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12” are rearranged pattern number sequences “4” based on the embedded data sequence d. , 6, 10, 9, 12, 0, 1, 3, 2, 7, 8, 5, 11 ".

  The image processing apparatus 1 rearranges the index values Pa (0) to Pa (12) in the first palette table according to the rearrangement pattern obtained in step S15 (step S16). For example, in the rearrangement pattern, since “0” is at the position “5” in the original sequence, the index value Pa (0) is converted to the index value Pa ′ (5). In the rearrangement pattern, since “1” is at the position “6” in the original number sequence, the index value Pa (1) is converted to the index value Pa ′ (6). Similarly, the index values Pa (2), Pa (3), Pa (4), Pa (5), Pa (6), Pa (7), Pa (8), Pa (9), Pa (10), Pa (11) and Pa (12) are index values Pa ′ (8), Pa ′ (7), Pa ′ (0), Pa ′ (11), Pa ′ (1), Pa ′ (9), Pa '(10), Pa' (3), Pa '(2), Pa' (12), and Pa '(4), respectively. In this way, the index values Pa (0) to Pa (12) are rearranged based on the embedded data strings d (0) to (3).

  The image processing apparatus 1 converts the index value of the pixel data Px according to the rearranged index values Pa ′ (0) to Pa ′ (12) (step S17). That is, the index values Pa (0) to Pa (12) of the pixel data Px are replaced with the index values Pa ′ (0) to Pa ′ (12). Through the above steps S11 to S17, the rearrangement process of the index values Pa (0) to Pa (12) of the first group is completed.

  Subsequently, the image processing apparatus 1 returns to step S11 and executes the rearrangement process of the index values Pa (13) to Pa (25) of the second group (steps S12 to S17). The index values Pa (13) to Pa (25) of the second group are rearranged into index values Pa ′ (13) to Pa ′ (25) based on the embedded data strings d (4) to d (7), and the pixels The index values Pa (13) to Pa (25) of the data Px are converted into index values Pa ′ (13) to Pa ′ (25).

  The image processing apparatus 1 repeats the processes of steps S12 to S17 until the index value Pa that has not been rearranged becomes less than 13 (NO in step S11). With the above processing, as shown in FIG. 12, the index values Pa (0) to Pa (12) of the first group to the index values Pa (234) to Pa (246) of the 19th group are rearranged. Is done. The index value Pa of each group is rearranged into the index value Pa ′ based on the embedded data string d every 4 bytes of the embedded data. Since the index values Pa (247) to Pa (255) of the last group are less than 13, no rearrangement is performed. In this way, the first pallet table is rearranged to the second pallet table.

  FIG. 9 is a flowchart showing the data extraction process, and FIG. 10 is a diagram for explaining a pallet information rearrangement procedure in the data extraction process. The image processing apparatus 2 executes the processes shown in FIGS. 9 and 10 to extract the embedded data strings d (0) to d (75) embedded in the converted image data by the processes of FIGS. It becomes possible. The image processing device 2 receives the converted image data from the image processing device 1. Further, it is assumed that the image processing apparatus 2 shares a predetermined rule for the arrangement order of the index values Pa with the image processing apparatus 1.

  First, the image processing apparatus 2 determines whether there are 13 or more index values Pa ′ that are not rearranged in the second palette table (step S21). If the number of index values that have not been rearranged is less than 13 (NO in step S21), the image processing apparatus 2 ends the rearrangement process.

  When there are 13 or more pallet information items that have not been rearranged (YES in step S21), the image processing apparatus 2 reads 13 from the top of the index values Pa ′ (0) to Pa ′ (255) from the second pallet table. The index values Pa ′ (0) to Pa ′ (12) are taken out as the first group (step S22). As shown in FIG. 10, the palette information Pa ′ (0) associated with the index value Pa ′ (0) indicates RGB (0, 64, 64) values, and is associated with the index value Pa ′ (1). The obtained palette information Pa ′ (1) indicates RGB (0, 128, 128) values. Further, the palette information Pa ′ (12) associated with the index value Pa ′ (12) indicates a value of RGB (128, 0, 0).

  Next, the image processing apparatus 2 rearranges the retrieved index values Pa ′ (0) to Pa ′ (12) according to a predetermined rule (step S23). As described above, the predetermined rule is the same as that used in the image processing apparatus 1. That is, the index value Pa ′ is rearranged in ascending order of the R, G, and B color components, as in the predetermined rule used in step S13. Therefore, as shown in FIG. 10, the index values Pa ′ (0) to Pa ′ (12) are Pa ′ (5), Pa ′ (6), Pa ′ (8), Pa ′ (7), Pa ′ (0), Pa ′ (11), Pa ′ (1), Pa ′ (9), Pa ′ (10), Pa ′ (3), Pa ′ (2), Pa ′ (12), Pa ′ Rearranged in the order of (4).

  The image processing apparatus 2 compares the arrangement order of the index values Pa ′ in step S22 with the arrangement order of the index values Pa ′ rearranged in step S23, and acquires a rearrangement pattern (step S24). The rearrangement pattern corresponds to the rearrangement order (sorting order) of the rearranged index values Pa ′ (0) to Pa ′ (12). For example, since the index value Pa ′ (0) is rearranged fourth from 0, “4” is obtained. Also, since the index value Pa ′ (1) is rearranged sixth, “6” is obtained. In this way, the rearrangement pattern “4, 6, 10, 9, 12, 0, 1, 3, 2, 7, 8, 5, 11” of the index values Pa ′ (0) to Pa ′ (12) is obtained. can get.

  Subsequently, the image processing apparatus 2 obtains a Lehmer code from the rearrangement pattern acquired in step S24, and further calculates a factorial number from the Lehmer code (step S25). As shown in FIG. 11, the Lehmer code “4, 5, 8, 7, 8, 0, 0, 1, 0, 1, 1, 0, 0” corresponding to the above rearrangement pattern is obtained. The factorial number “2,147,483,648” of the Lehmer code is obtained. Furthermore, by representing “2,147,483,648” in a bit string, a 32-bit data string “1000 — 0000 — 0000 — 0000 — 0000 — 0000 — 0000 — 0000” is obtained. Accordingly, the embedded data strings d (0), d (1), d (2), and d (3) are extracted from the index values Pa ′ (0) to Pa ′ (12) of the first group (step S26). ).

  Subsequently, the image processing apparatus 2 returns to step S21, and extracts embedded data strings d (4) to d (7) from the index values Pa ′ (13) to Pa ′ (25) of the second group (step S22 to step S22). S26). That is, by calculating the rearrangement pattern Lehmer code and the factorial number corresponding to the index values Pa ′ (13) to Pa ′ (25), the embedded data strings d (4) to d (7) are extracted. Further, the image processing apparatus 2 repeats the processing of steps S22 to S26 until the index value Pa ′ in the second palette table is less than 13 (NO in step S21), and as shown in FIG. The embedded data strings d (0) to d (75) can be taken out.

According to the present embodiment, it is possible to embed information without any deterioration in image quality by rearranging the index values in the palette table based on the embedded data string. Further, according to the present embodiment, since an additional information area depending on the file format is not required, information is embedded only with the palette table. Therefore, information can be embedded without depending on the file format of the image data.
The first image processing apparatus may also have the function of the second image processing apparatus, and the second image processing apparatus may also have the function of the first image processing apparatus.

(Second Embodiment)
FIG. 13 is a block diagram of the image processing system in the present embodiment. The image processing system in the present embodiment includes a first image processing apparatus 1 and a second image processing apparatus 2. The first image processing apparatus 1 includes an input unit 1a, a rearrangement unit 1b, a conversion unit 1c, and an output unit 1d, and the second image processing apparatus 2 includes an input unit 2a and an extraction unit 2b. In the first image processing apparatus 1, the input means 1a inputs image data including a first palette table in which a plurality of index values associated with palette information defining color information are arranged according to a predetermined rule. The rearranging means 1b rearranges the index values based on the embedded data, and converts the first palette table into the second palette table. The conversion unit 1c converts the index value of the first palette table associated with each pixel constituting the image data into the index value of the second palette table. The output unit 1d outputs converted image data including the second palette table. In the second image processing apparatus 2, the input means 2a inputs the converted image data. The extracting unit 2b extracts embedded data based on the order of the index values in the second palette table of the converted image data and a predetermined rule.

According to the present embodiment, it is possible to embed information without any deterioration in image quality. Further, it is possible to embed information only by palette information without depending on the file format of image data.
The first image processing apparatus may also have the function of the second image processing apparatus, and the second image processing apparatus may also have the function of the first image processing apparatus.

  A part or all of the above-described embodiment can be described as in the following supplementary notes, but is not limited thereto.

(Appendix 1)
An image processing system including a first image processing device and a second image processing device,
The first image processing apparatus includes:
Input means for inputting image data including a first palette table in which a plurality of index values associated with palette information defining color information are arranged according to a predetermined rule;
Reordering means for reordering the index values based on an embedded data string and converting the first pallet table to a second pallet table;
Converting means for converting the index value of the first palette table associated with each pixel constituting the image data into the index value of the second palette table;
Output means for outputting converted image data including the second palette table,
The second image processing apparatus includes:
Means for inputting the converted image data;
An image processing system comprising: extraction means for extracting the embedded data string based on the order of the index values in the second palette table of the converted image data and the predetermined rule.

(Appendix 2)
The image processing system according to claim 1, wherein the rearranging unit divides the index value into a plurality of groups and rearranges the index values for each group.

(Appendix 3)
The reordering unit can embed the embedded data string of M bits (M is a maximum integer not exceeding log2 (n!)) By reordering the n index values. The image processing system according to 2.

(Appendix 4)
The plurality of groups include G groups each having n index values, and the rearranging unit rearranges the index values for each group, whereby the embedded data of G × M bits is obtained. The image processing system according to appendix 3, wherein the columns can be embedded.

(Appendix 5)
The image processing system according to claim 3 or 4, wherein the rearranging unit rearranges the n index values based on a Lehmer code calculated using the embedded data string of M bits as a factorial number.

(Appendix 6)
Input means for inputting image data including a first palette table in which a plurality of index values associated with palette information defining color information are arranged according to a predetermined rule;
Reordering means for reordering the index values based on an embedded data string and converting the first pallet table to a second pallet table;
Converting means for converting the index value of the first palette table associated with each pixel constituting the image data into the index value of the second palette table;
An image processing apparatus comprising: output means for outputting converted image data including the second palette table.

(Appendix 7)
In the image data including a first palette table in which a plurality of index values associated with palette information defining color information are arranged according to a predetermined rule, the index values are rearranged based on an embedded data string, thereby The pallet table is converted into a second pallet table, and the converted image obtained by converting the index value of the first pallet table associated with each pixel constituting the image data into the index value of the second pallet table An input means for inputting data;
An image processing apparatus comprising: extraction means for extracting the embedded data string based on the order of the index values of the converted image data in the second palette table and the predetermined rule.

(Appendix 8)
Inputting image data including a first palette table in which a plurality of index values associated with palette information defining color information are arranged according to a predetermined rule;
Rearranging the index values based on an embedded data string and converting the first palette table to a second palette table;
Converting the index value of the first palette table associated with each pixel constituting the image data into the index value of the second palette table;
And a step of outputting converted image data including the second pallet table.

(Appendix 9)
In the image data including a first palette table in which a plurality of index values associated with palette information defining color information are arranged according to a predetermined rule, the index values are rearranged based on an embedded data string, thereby The pallet table is converted into a second pallet table, and the converted image obtained by converting the index value of the first pallet table associated with each pixel constituting the image data into the index value of the second pallet table Entering data, and
An image processing method comprising: extracting the embedded data string based on the order of the index values in the second palette table of the converted image data and the predetermined rule.

(Appendix 10)
Inputting image data including a first palette table in which a plurality of index values associated with palette information defining color information are arranged according to a predetermined rule;
Rearranging the index values based on an embedded data string and converting the first palette table to a second palette table;
Converting the index value of the first palette table associated with each pixel constituting the image data into the index value of the second palette table;
A program for causing a computer to execute an image processing method including a step of outputting converted image data including the second palette table.

DESCRIPTION OF SYMBOLS 1 Image processing apparatus 2 Image processing apparatus 3 Communication line 11 CPU
12 bus 13 RAM
14 Storage 15 Keyboard 16 Display 17 Interface 101 Rearrangement Unit 102 Conversion Unit 201 Rearrangement Unit

Claims (10)

An image processing system including a first image processing device and a second image processing device,
The first image processing apparatus includes:
Input means for inputting image data including a first palette table in which a plurality of index values associated with palette information defining color information are arranged according to a predetermined rule;
Reordering means for reordering the index values based on an embedded data string and converting the first pallet table to a second pallet table;
Converting means for converting the index value of the first palette table associated with each pixel constituting the image data into the index value of the second palette table;
Output means for outputting converted image data including the second palette table,
The second image processing apparatus includes:
Means for inputting the converted image data;
An image processing system comprising: extraction means for extracting the embedded data string based on the order of the index values in the second palette table of the converted image data and the predetermined rule.   The image processing system according to claim 1, wherein the rearranging unit divides the index value into a plurality of groups and rearranges the index values for each group.   The reordering means can embed the embedded data string of M bits (M is a maximum integer not exceeding log2 (n!)) By reordering n index values. Item 3. The image processing system according to Item 2.   The plurality of groups include G groups each having n index values, and the rearranging unit rearranges the index values for each group, whereby the embedded data of G × M bits is obtained. The image processing system according to claim 3, wherein the columns can be embedded.   5. The image processing system according to claim 3, wherein the rearranging unit rearranges the n index values based on a Lehmer code calculated using the embedded data string of M bits as a factorial number. . Input means for inputting image data including a first palette table in which a plurality of index values associated with palette information defining color information are arranged according to a predetermined rule;
Reordering means for reordering the index values based on an embedded data string and converting the first pallet table to a second pallet table;
Converting means for converting the index value of the first palette table associated with each pixel constituting the image data into the index value of the second palette table;
An image processing apparatus comprising: output means for outputting converted image data including the second palette table. In the image data including a first palette table in which a plurality of index values associated with palette information defining color information are arranged according to a predetermined rule, the index values are rearranged based on an embedded data string, thereby The pallet table is converted into a second pallet table, and the converted image obtained by converting the index value of the first pallet table associated with each pixel constituting the image data into the index value of the second pallet table An input means for inputting data;
An image processing apparatus comprising: extraction means for extracting the embedded data string based on the order of the index values of the converted image data in the second palette table and the predetermined rule. Inputting image data including a first palette table in which a plurality of index values associated with palette information defining color information are arranged according to a predetermined rule;
Rearranging the index values based on an embedded data string and converting the first palette table to a second palette table;
Converting the index value of the first palette table associated with each pixel constituting the image data into the index value of the second palette table;
And a step of outputting converted image data including the second pallet table. In the image data including a first palette table in which a plurality of index values associated with palette information defining color information are arranged according to a predetermined rule, the index values are rearranged based on an embedded data string, thereby The pallet table is converted into a second pallet table, and the converted image obtained by converting the index value of the first pallet table associated with each pixel constituting the image data into the index value of the second pallet table Entering data, and
An image processing method comprising: extracting the embedded data string based on the order of the index values in the second palette table of the converted image data and the predetermined rule. Inputting image data including a first palette table in which a plurality of index values associated with palette information defining color information are arranged according to a predetermined rule;
Rearranging the index values based on an embedded data string and converting the first palette table to a second palette table;
Converting the index value of the first palette table associated with each pixel constituting the image data into the index value of the second palette table;
A program for causing a computer to execute an image processing method including a step of outputting converted image data including the second palette table.

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