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

Abstract

To provide an image processing device, a control method of the image processing device, and a program capable of appropriately determining an authenticity guaranty of an image so that an authenticity of the image can be confirmed in accordance with an object by a user.SOLUTION: An image processing device 300 comprises: information determination means for determining whether or not record information 207 in regard to a history of an edition performed to an image is added; detection means for detecting the number of history information 207 in the case where it is determined that the record information 207 is added as a result of a determination in the information determination means; authenticity secure determination means for gradually determining an authenticity of the image on the basis of a result of a detection in the detection means; and notification means for notifying a result of the determination in the authenticity secure determination means.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to an image processing apparatus, a control method for an image processing apparatus, and a program. [Background technology]

[0002] Authenticity assurance that guarantees that an image has not been tampered with has been required for a long time. For example, authenticity assurance can guarantee that images handled by administrative agencies such as police and judicial agencies such as courts have not been tampered with, and can guarantee that images published in media such as newspapers and online news have not been tampered with. For example, Patent Document 1 discloses a data certification device that attaches original data to be certified and creates an intermediate file containing certification matters. The data certification device described in Patent Document 1 can create a certified file by attaching date and time certification information including a hash value of the intermediate file, and can prove whether or not the original data and certification matters have been tampered with. In addition, a technology that guarantees the origin and reliability of content such as images has been developed. In addition, a technical standardization organization "C2PA" has been established with the aim of enabling publishers, image creators, general users (consumers) who view images, etc. to track the origin of content. Thus, the need for authenticity assurance has been attracting attention in recent years. In addition, in the C2PA standard, a "Manifest" can be saved as C2PA data in an image generated at the time of shooting or editing. This manifest can store, for example, "Actor" such as the camera name or software name, "Hash" or "claim signature" such as a digital signature, a thumbnail image, and so on. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2012-34329 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, there are cases in which a user wants to check the authenticity of an image, such as whether the user wants to check that the image data is guaranteed to be the same as it was recorded when the image was shot, or whether the image may have been edited but the photographer, editor, etc., are guaranteed as an editing history, etc. In this way, there are a wide variety of reasons why users want to check the authenticity of an image.

[0005] The present invention has been made in view of the above problems, and aims to provide an image processing device, a control method for the image processing device, and a program that can appropriately determine whether an image is authentic so that a user can easily check the authenticity of the image according to his or her purpose. [Means for solving the problem]

[0006] In order to achieve the above-mentioned object, the image processing device of the present invention is characterized in comprising an acquisition means for acquiring an image, an information determination means for determining whether or not the image acquired by the acquisition means has history information regarding the editing history of the image added to it, a detection means for detecting the number of pieces of history information when it is determined as a result of the determination by the information determination means that the history information has been added, an authenticity assurance determination means for determining in stages the authenticity of the image based on the detection result by the detection means, and a notification means for notifying the result of the determination by the authenticity assurance determination means. Effect of the Invention

[0007] According to the present invention, the authenticity of an image can be appropriately determined. [Brief description of the drawings]

[0008] [Figure 1] 1 is a block diagram showing an example of a hardware configuration of an imaging apparatus according to a first embodiment. [Diagram 2] FIG. 2 is a diagram showing an example of an outline of the recorded contents of an image file. [Diagram 3]10 is a flowchart showing a process for determining the authenticity of an image, which is executed by an imaging device. [Figure 4] 10 is a flowchart showing a process for determining the authenticity of an image, which is executed in an imaging device according to a second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Each embodiment of the present invention will be described in detail below with reference to the drawings. However, the configurations described in each of the following embodiments are merely examples, and the scope of the present invention is not limited by the configurations described in each embodiment. For example, each part constituting the present invention can be replaced with any configuration that can exert a similar function. In addition, any configuration may be added. In addition, any two or more configurations (features) of each embodiment can be combined.

[0010] First Embodiment Hereinafter, the first embodiment will be described with reference to Figs. 1 to 3. Fig. 1 is a block diagram showing an example of a hardware configuration of an imaging device according to the first embodiment. In this embodiment, the imaging device shown in Fig. 1 is applied to a digital camera 100. Note that the imaging device is not limited to the digital camera 100, and may be, for example, a personal computer with a camera, a tablet terminal with a camera, a smartphone, etc. The digital camera 100 has a barrier 10, a photographing lens 11, a shutter 12, an imaging element 13, a timing generator 14, an A / D converter 15, an image processing unit 20, a D / A converter 21, a memory control unit 22, a display unit 23, an image display memory 24, and a memory 25. The digital camera 100 also has an exposure control unit 40, a focus control unit 41, a zoom control unit 42, a barrier control unit 43, a flash 44, a system control unit 50, a non-volatile memory 51, a shutter button 60, and an operation unit 63. The digital camera 100 also includes a metadata generating and analyzing unit 70, a communication unit 71, a hash value generating unit 72, a hash value comparing unit 73, a power supply 80, a power supply control unit 81, a card controller 90, and an external recording medium 91. In this embodiment, the image processing unit 20, the system control unit 50, the metadata generating and analyzing unit 70, the hash value generating unit 72, and the hash value comparing unit 73 constitute an image processing device 300 that performs image processing related to authenticity assurance, which will be described later. Here, "authenticity assurance" refers to assurance that an image captured by the digital camera 100 has not been tampered with (the image has not been tampered with), that is, that the image has not been unfairly (misused) altered. In addition, a program for causing the system control unit to execute each unit and each means (a control method of the image processing device) of the image processing device 300 is stored in advance in, for example, a non-volatile memory 51.

[0011] The barrier 10 is a protective member that covers the photographing lens 11 to prevent the photographing lens 11 from being soiled or damaged. The operation of the barrier 10 is controlled by the barrier control unit 43. The photographing lens 11 forms an optical image on the imaging surface of the imaging element 13. The shutter 12 has an aperture function. The imaging element 13 is an imaging means for capturing an image, and is composed of, for example, a CCD or CMOS sensor. The imaging element 13 converts the optical image formed on the imaging surface by the photographing lens 11 into an electric signal. The A / D converter 15 converts an analog image signal output from the imaging element 13 into a digital image signal. The digital image signal converted by the A / D converter 15 is written into the memory 25 as RAW image data. In addition, development parameters corresponding to each RAW image data are generated based on information at the time of shooting, and are written into the memory 25. The development parameters are composed of various parameters used in image processing for recording, such as exposure setting, white balance, color space, contrast, and JPEG format. The timing generator 14 is controlled by the memory control unit 22 and the system control unit 50. This enables the timing generator 14 to supply clock signals and control signals to the image sensor 13, the A / D converter 15, and the D / A converter 21.

[0012] The image processing unit 20 performs various image processing such as predetermined pixel interpolation processing, color conversion processing, correction processing, resizing processing, image synthesis processing, etc., on the data from the A / D converter 15 or the data from the memory control unit 22. The image processing unit 20 also performs predetermined image processing and calculation processing using image data obtained by the imaging element 13. The image processing unit 20 then provides the calculation results to the system control unit 50. The system control unit 50 controls the exposure control unit 40 and the focus control unit 41 based on the calculation results provided by the image processing unit 20. This allows AF (autofocus) processing, AE (autoexposure) processing, and EF (flash pre-emission) processing to be performed. The image processing unit 20 also performs predetermined calculation processing using the image data, and can also perform AWB (auto white balance) processing based on the calculation results. The image processing unit 20 also reads image data stored in the memory 25. The image processing unit 20 can perform compression processing and decompression processing, such as JPEG format, MPEG-4 AVC, HEVC (High Efficiency Video Coding), and lossless compression of uncompressed RAW data, on the image data. Then, the image processing unit 20 writes the processed image data into the memory 25.

[0013] The image processing unit 20 can perform various editing processes on the image data. Specifically, the image processing unit 20 can perform a trimming process to adjust the display range and size of the image by hiding unnecessary parts around the image data. The image processing unit 20 can also perform a resizing process to change the size by enlarging or reducing the image data and the display elements of the screen. The image processing unit 20 can also perform image processing such as color conversion on data that has been subjected to compression processing such as lossless compression and decompression processing on uncompressed RAW data. The image processing unit 20 can also perform RAW development to create image data by converting to the JPEG format. The image processing unit 20 can also perform a video clipping process to clip out a designated frame of a video format such as MPEG-4, convert it to the JPEG format, and save it. The image processing unit 20 also performs various image comparison processes on various image data. Specifically, the image processing unit 20 performs a decompression process according to the compression format of the image data to be compared. Then, the image processing unit 20 can perform a comparison using the decompressed image. As a result of this comparison, for example, it can be determined whether the images match or not, or the degree of difference between the images can be determined.

[0014] The image processing unit 20 also performs processing such as superimposing an OSD (On-Screen Display) such as a menu or arbitrary characters to be displayed on the display unit 23 together with image data for display. The image processing unit 20 also performs subject detection processing to detect a subject present in the image data and to detect the subject area using image data and distance information from the subject obtained from the image sensor 13 at the time of shooting. Examples of information that can be detected by the image processing unit 20 include the position, size, inclination, and likelihood in the image. The image processing unit 20 has a synthesis processing circuit that synthesizes multiple image data. This allows, for example, pixel overwriting and weighted addition to be performed. Furthermore, weighted addition can be used to create an image in which the background is visible through the image. Furthermore, comparatively bright synthesis processing and comparatively dark synthesis processing are possible, in which an image having the brightest or darkest value in each area of ​​the image data to be synthesized is selected, and the selected images are synthesized to generate one piece of image data.

[0015] The memory control unit 22 controls the A / D converter 15, the timing generator 14, the image processing unit 20, the image display memory 24, the D / A converter 21, and the memory 25. The RAW image data generated by the A / D converter 15 is written to the image display memory 24 or the memory 25 via the image processing unit 20 and the memory control unit 22, or directly via the memory control unit 22. The display image data written to the image display memory 24 is displayed on the display unit 23, which is composed of a TFT LCD or the like, via the D / A converter 21. By sequentially displaying the image data on the display unit 23, it is possible to realize, for example, an electronic finder function that displays live images. The memory 25 has a storage capacity sufficient to store a predetermined number of still images or a moving image for a predetermined time. The memory 25 can also be used as a working area for the system control unit 50. The exposure control unit 40 controls the shutter 12. The exposure control unit 40 also has a flash dimming function by linking with the flash 44. The focus control unit 41 drives a focus lens (not shown) included in the photographing lens 11 based on instructions from the system control unit 50. This allows focus adjustment. The zoom control unit 42 controls zooming by driving the zoom lens of the photographing lens 11. The flash 44 has an AF auxiliary light projection function and a flash dimming function. The system control unit 50 is a computer that has a CPU and controls the entire digital camera 100. The non-volatile memory 51 is an electrically erasable and recordable non-volatile memory, and for example, an EEPROM is used. Note that the non-volatile memory 51 also stores, for example, various programs and map information.

[0016] The shutter switch 61 is a switch (SW1) that is turned on during the operation of the shutter button 60. By turning on the shutter switch 61, it is possible to instruct the start of operations such as AF processing, AE processing, AWB processing, and EF processing. The shutter switch 62 is a switch (SW2) that is turned on when the operation of the shutter button 60 is completed. By turning on the shutter switch 62, it is possible to instruct the start of a series of shooting operations including exposure processing, development processing, and recording processing. In the exposure processing, a signal read from the image sensor 13 is written to the memory 25 as RAW image data via the A / D converter 15 and the memory control unit 22. In the development processing, the RAW image data written to the memory 25 is developed using calculations in the image processing unit 20 and the memory control unit 22, and written to the memory 25 as image data. In the recording processing, the image data is read from the memory 25 and compressed by the image processing unit 20. In the recording processing, the compressed image data is stored in the memory 25, and then written to the external recording medium 91 via the card controller 90. The operation unit 63 has operation members such as various buttons and a touch panel. The operation members are not particularly limited and include, for example, a power button, a menu button, a mode change switch for switching between shooting mode / playback mode / other special shooting modes, a cross key, a set button, a macro button, a multi-screen playback page break button, etc. Other operation members include, for example, a flash setting button, a single shot / continuous shot / self-timer switching button, a menu movement + (plus) button, a menu movement - (minus) button, a shooting image quality selection button, an exposure compensation button, a date / time setting button, etc.

[0017] When recording image data in the external recording medium 91, the metadata generating and analyzing unit 70 generates various metadata such as Exif (Exchangeable image file format) standard to be attached to the image data based on information at the time of shooting. When reading image data recorded in the external recording medium 91, the metadata generating and analyzing unit 70 analyzes the metadata added to the image data. The metadata is not particularly limited, but examples of the metadata include shooting setting information at the time of shooting, image data information related to the image data, and feature information of the subject included in the image data. When recording moving image data, the metadata generating and analyzing unit 70 can also generate metadata for each frame and add it to each frame. The power supply 80 is composed of, for example, a primary battery such as an alkaline battery, a secondary battery such as a NiCd battery, a NiMH battery, or a Li battery, an AC adapter, etc. The power supply control unit 81 supplies power supplied from the power supply 80 to each unit of the digital camera 100. The card controller 90 transmits and receives data to and from the external recording medium 91. The external recording medium 91 is composed of, for example, a memory card, and images (still images, moving images) captured by the digital camera 100 are recorded therein. The communication unit 71 has a communication circuit for transmitting and receiving. The communication in the communication unit 71 may be wireless communication such as Wi-Fi (registered trademark) or Bluetooth (registered trademark), or may be wired communication such as Ethernet or USB.

[0018] An image file (image) is input to the system control unit 50, that is, the system control unit 50 acquires the image file (acquisition process). Thus, in this embodiment, the system control unit 50 also functions as an acquisition means for acquiring the image file. The hash value generation unit 72 generates (calculates) a hash value for the image file input via the system control unit 50 using a hash function. Note that, although the hash value generation is performed by the hash value generation unit 72 in this embodiment, this is not limited to this and may be performed by, for example, the system control unit 50. Also, although the target for which the hash value is generated is an image file in this embodiment, this is not limited to this and may be, for example, image data.

[0019] When the digital camera 100 (image processing device 300) judges whether the image file is authentic, it first determines an image file to be judged. This determination is made, for example, by a user of the digital camera 100 operating the operation unit 63 to select the image file to be judged on the display unit 23. A hash value (hereinafter referred to as a "primary hash value") is generated for this image file by the hash value generation unit 72 in advance, that is, before the judgment of the authenticity of the image file. The primary hash value is linked to the image file. Furthermore, when judging the authenticity of the image file, the hash value generation unit 72 generates a new hash value (hereinafter referred to as a "secondary hash value") for the image file. The secondary hash value is also linked to the image file like the primary hash value. Then, the hash value comparison unit 73 compares the primary hash value with the secondary hash value. Based on the result of this comparison, it is judged whether the image file is authentic. For example, when the primary hash value and the secondary hash value are the same, the image file to be judged for authenticity is the same as the original image file, and is therefore judged to have not been tampered with, i.e., to be true. On the other hand, when the primary hash value and the secondary hash value are different, the image file is judged to be different from the original image file, and is therefore judged to have been tampered with, i.e., not true but false. Note that, when at least one of the primary hash value and the secondary hash value is not acquired from the image data to be judged, it is unclear whether the image file has been tampered with, i.e., it is judged to be neither true nor false. In addition, in this embodiment, the comparison of hash values ​​is performed by the hash value comparison unit 73, but is not limited thereto, and may be performed by, for example, the system control unit 50.

[0020] FIG. 2 is a diagram showing an example of the outline of the recorded contents of an image file. FIG. 2(a) is a diagram showing a case where the recorded contents of an image file include one piece of history information. FIG. 2(b) is a diagram showing a case where the recorded contents of an image file include two pieces of history information. "History information" refers to information on the history of editing performed on an image. As will be described later, the history information 207 in this embodiment includes an actor 221, a hash value 222, a thumbnail image 223, and a signature 224. As shown in FIG. 2(a) and FIG. 2(b), in an image file 200, a recording area 201, a thumbnail recording area 205, and an image data area 206 are secured as areas for recording the recorded contents. In the recording area 201, metadata conforming to at least the Exif standard is recorded by using the metadata generating / analyzing unit 70. In addition, authenticity assurance information 202 and a maker note 204 are recorded in the recording area 201. The authenticity assurance information 202 includes history information 207. In the authenticity assurance information 202, the history information 207 can be reached by offsetting the number of bytes of the authenticity information link 203. Image data of thumbnail images is recorded in the thumbnail recording area 205. Image data of the original image (original image data) is recorded in a compressed state in the image data area 206.

[0021] For example, when the user instructs the image file 200 to be recorded in the JPEG format, the image data is recorded in the image data area 206 in the JPEG format. The authenticity assurance information 202, the history information 207, and the like are recorded with an APP1 marker, and the like. When the user instructs the image file 200 to be recorded in the HEIF (High Efficiency Image File Format) format, the image data is recorded in the image data area 206 in the HEIF file format. The authenticity assurance information 202, the history information 207, and the like are recorded in a Metadata Box as the recording area 201. Similarly, when the user instructs the image file 200 to be recorded in the RAW format, the authenticity assurance information 202, the history information 207, and the like are recorded in a Metadata Box as the recording area 201. Note that the recording format is not limited to the JPEG format, the HEIF file format, and the RAW format. In some cases, metadata specific to the manufacturer of the digital camera 100 is recorded in a format that is generally not publicly disclosed in the maker note 204.

[0022] The image file 200 shown in FIG. 2(a) includes one piece of history information (history information 216) as the history information 207. The image file 200 shown in FIG. 2(b) includes two pieces of history information (history information 217 and history information 218) as the history information 207. In this embodiment, the history information 216 to history information 218 each include, but are not limited to, an actor 221, a hash value 222, a thumbnail image 223, and a signature 224. The actor 221 is the name of the digital camera 100 that generated the image file 200 (image), or the name of the software (program) stored in the digital camera 100. The hash value 222 is any one of a hash value of the image file 200, a hash value of metadata, and a hash value of the image and metadata. The thumbnail image 223 is a thumbnail image at the time when the history information 207 is added. The signature 224 is the name of the user who operated the digital camera 100. The history information 216 and the history information 217 are added when the image in the image file 200 was initially captured, that is, immediately after the image was captured. The history information 218 is added when the image to which the history information 217 is added is edited, for example, by using an editing application. In this case, the image in the image file 200 is edited once when it was initially captured. In the image file 200 shown in FIG. 2B, the history information 218 is the latest history information. When recording a plurality of pieces of history information 207, management information such as a link destination to the history information 207, the number of pieces of history information 207, and the latest history information 207 may be added to the beginning of each piece of history information 207. A plurality of pieces of history information may be recorded in the order of addition, and the last piece of history information may be the latest history information. Also, information indicating which history information 207 was added at the beginning of shooting may be included.

[0023] FIG. 3 is a flowchart showing a process of determining the authenticity of an image, which is executed by the imaging device. Here, a configuration is described that enables the determination of whether an image is an image that was originally captured (hereinafter referred to as an "original image") or an image that is not an original image but has a guaranteed editing history, based on the number of pieces of history information. As shown in FIG. 3, in step S301, the system control unit 50 controls the metadata generating and analyzing unit 70, so that the metadata generating and analyzing unit 70 determines whether the history information 207 is added to the image to be determined for authenticity (information determining step). Thus, in this embodiment, the metadata generating and analyzing unit 70 functions as an information determining unit, but is not limited thereto. For example, a part that functions as an information determining unit may be provided separately from the metadata generating and analyzing unit 70. Then, if it is determined that the history information 207 is added as a result of the determination in step S301, the process proceeds to step S303. On the other hand, if it is determined that the history information 207 is not added as a result of the determination in step S301, the process proceeds to step S302.

[0024] In step S302, the system control unit 50 determines that it is impossible to determine whether the image is authentic. In addition, in response to this determination, the system control unit 50 (notification means) notifies the result of the determination. For example, the display unit 23 may display a message indicating that "authenticity is not guaranteed," or a process may be executed to restrict playback of images to which the history information 207 is not added. After step S302 is executed, the process ends.

[0025] In step S303, the system control unit 50 judges whether the history information 207 is correct, that is, whether the history information 207 is correct (correctness judgment process). In this way, in this embodiment, the system control unit 50 also functions as a correctness judgment means for judging the correctness of the history information 207, but is not limited thereto. For example, a part functioning as the correctness judgment means may be provided separately from the system control unit 50. In addition, the judgment in step S303 is made based on a comparison result by the hash value comparison unit 73 using a hash value. Specifically, the hash value comparison unit 73 compares a primary hash value generated before the current judgment of authenticity assurance with a secondary hash value generated by the hash value generation unit 72 from the image in the image data area 206 in the current judgment of authenticity assurance. If the primary hash value and the secondary hash value are the same, the system control unit 50 judges that the history information 207 is correct. On the other hand, if the primary hash value and the secondary hash value are different, the system control unit 50 judges that the history information 207 is incorrect, that is, erroneous. For example, when the image file 200 shown in FIG. 2(a) is to be judged for authenticity, the primary hash value is "a03f4f5f" which is the hash value 222 in the history information 216. The hash value comparison unit 73 compares this "a03f4f5f" with a secondary hash value (not shown) generated from the image in the image data area 206. When the image file 200 shown in FIG. 2(b) is to be judged for authenticity, the primary hash value is "b04e5f5b" which is the hash value 222 in the history information 218 which is the latest history information. The hash value comparison unit 73 compares this "a03f4f5f" with a secondary hash value (not shown) generated from the image in the image data area 206. When the result of the judgment in step S303 indicates that the history information 207 is correct, the process proceeds to step S305. On the other hand, if it is determined in step S303 that the history information 207 is not correct, the process proceeds to step S304.

[0026] After step S303, it is determined whether the image to be judged for authenticity has been tampered with based on the result of the judgment in step S303 (tampering judgment step). This judgment is made by the system control unit 50. Thus, in this embodiment, the system control unit 50 also functions as a tampering judgment means for judging whether the image has been tampered with, but is not limited to this. For example, a part that functions as the tampering judgment means may be provided separately from the system control unit 50.

[0027] In step S304, the system control unit 50 determines that the image cannot be guaranteed to be authentic (it is not possible to guarantee that the image has not been tampered with), i.e., that the image being judged for authenticity has been tampered with. In addition, accompanying this judgment, the system control unit 50 notifies the result of the judgment. For example, the system control unit 50 may display "no guarantee of authenticity" or "tampered with" on the display unit 23, or may execute processing to restrict playback of tampered images (history information 207 is false). After executing step S304, the processing ends.

[0028] In step S305, the system control unit 50 detects the number of pieces of history information 207 (detection step). Thus, in this embodiment, the system control unit 50 also functions as a detection unit that detects the number of pieces of history information 207, but is not limited thereto. For example, a part that functions as a detection unit may be provided separately from the system control unit 50. In addition, in this embodiment, the system control unit 50 determines whether the number of pieces of history information 207 is one or not as the detection of the number of pieces of history information 207. For example, when the image file 200 shown in FIG. 2(a) is the target of the determination of authenticity assurance, one piece of history information (history information 216) is included as the history information 207, so in step S305, it is determined that the number of pieces of history information 207 is one. In addition, when the image file 200 shown in FIG. 2(b) is the target of the determination of authenticity assurance, two pieces of history information (history information 217 and history information 218) are included as the history information 207, so in step S305, it is determined that the number of pieces of history information 207 is not one. Then, if it is determined in step S305 that the number of pieces of history information 207 is one, the process proceeds to step S307. On the other hand, if it is determined in step S305 that the number of pieces of history information 207 is not one, that is, that there are a plurality of pieces of history information 207, the process proceeds to step S306.

[0029] After step S305, it is determined whether or not editing has been performed on the original image at least once based on the result of the detection in step S305 (editing determination process (authenticity assurance determination process)). This determination is performed by the system control unit 50. Thus, in this embodiment, the system control unit 50 also functions as an editing determination means (authenticity assurance determination means) that determines whether or not editing has been performed on the original image at least once, but is not limited to this. For example, a part that functions as the editing determination means may be provided separately from the system control unit 50.

[0030] In step S306, the system control unit 50 determines that the image is authentic (it can be guaranteed that the image has not been tampered with) and that the editing history is guaranteed, but that at least one edit has been made to the original image, that is, that the image is not an original image. "The editing history is guaranteed" means that the photographer, editor, etc. is guaranteed to be the editor of the original image. In addition, in conjunction with this determination, the system control unit 50 notifies the result of the determination. For example, the display unit 23 may display "not an original image" or "the editing history is guaranteed," or a process may be performed to restrict playback of images that are not original images. After step S306 is performed, the process ends.

[0031] In step S307, the system control unit 50 determines that the image is authentic (it can be guaranteed that the image has not been tampered with) and has not been edited even once, i.e., that the image is an original image. In addition, in conjunction with this determination, the system control unit 50 notifies the result of the determination. For example, the display unit 23 may display "original image." After step S307 is executed, the processing ends. In this way, if it is determined that the image to be determined as authentic has not been edited even once, it is considered to be an original image, and if it is determined that it has been edited at least once, it is considered not to be an original image.

[0032] As described above, the digital camera 100 (image processing device 300) can appropriately perform a stepwise determination of the authenticity of an image. Specifically, when determining the authenticity of an image, first, it is accurately determined whether the image to be determined is an original image (whether or not it has been tampered with), and then it is accurately determined whether the image may have been edited but the editing history is guaranteed. Furthermore, if it is determined that the history information 207 has not been added as a result of the determination in step S301, the determination of the presence or absence of tampering is omitted. This makes it possible to prevent unnecessary determination of the presence or absence of tampering. Furthermore, the determination target in steps S301 and S303 is the history information 207, but is not limited thereto, and may be the authenticity assurance information 202 including the history information 207. Furthermore, in this embodiment, the determination of whether the image is an original image is performed based on the number of pieces of history information 207, but is not limited thereto. For example, information on whether the history information is taken or edited may be added to the history information 207, and the determination of whether the image is an original image may be performed based on the additional information.

[0033] <Second embodiment> Hereinafter, the second embodiment will be described with reference to FIG. 4, but the differences from the above-mentioned embodiment will be mainly described, and the description of the similar matters will be omitted. FIG. 4 is a flowchart showing a process for determining the authenticity of an image, which is executed by an imaging device according to the second embodiment. As shown in FIG. 4, steps S401 to S405 are the same as steps S301 to S305 in the flowchart shown in FIG. 3. If it is determined in step S405 that there is only one piece of history information 207, the process proceeds to step S409. On the other hand, if it is determined in step S405 that there is not only one piece of history information 207, the process proceeds to step S406.

[0034] In step S406, the system control unit 50 uses the thumbnail image 223 included in the history information 207 to determine whether the difference between the image and the original image is sufficiently small. For example, when the image file 200 shown in FIG. 2B is to be determined for authenticity, the thumbnail image 223 in the history information 217 added at the beginning of image capture is compared with the thumbnail image 223 in the latest history information 218. Here, the thumbnail image 223 in the history information 217 is the original image. The image processing unit 20 compares the two thumbnail images 223 to calculate the difference. Then, the system control unit 50 determines whether the difference calculated by the image processing unit 20 is below a threshold (is smaller than a predetermined value). The threshold can be appropriately set or changed using, for example, the operation unit 63. Alternatively, instead of this determination, for example, a determination may be made as to whether the two thumbnail images 223 completely match each other. Alternatively, the thumbnail image 223 in the latest history information 218 may be compared with the original image in the image data area 206, or the thumbnail image 223 in the latest history information 218 may be compared with the thumbnail image in the thumbnail recording area 205.

[0035] In step S407, the system control unit 50 determines that the image is authentic and has a guaranteed editing history, but is not an original image. In addition, in conjunction with this determination, the system control unit 50 notifies the result of the determination. For example, the display unit 23 may display "not an original image" or "guaranteed editing history", or a process may be executed to restrict playback of images that are not original images. After step S407 is executed, the process ends.

[0036] In step S408, the system control unit 50 determines that the image is authentic and is an original image. Here, "it is an original image" may mean the original image itself, or it may be an image that is not an original image but has been edited to a negligible extent without relatively large changes from the original image. In addition, in conjunction with this determination, the system control unit 50 notifies the result of the determination. For example, the display unit 23 may display "it is an original image" or "it is an image that has been edited to a negligible extent without relatively large changes from the original image." After step S408 is executed, the process ends.

[0037] In step S409, the system control unit 50 determines that the image is authentic and is an original image. In addition, along with this determination, the system control unit 50 notifies the result of the determination. For example, the display unit 23 may display "This is an original image." After step S409 is executed, the process ends.

[0038] As described above, in this embodiment, when a plurality of pieces of history information 207 are detected, the image processing unit 20 compares the pieces of history information 207. Then, when the difference as a result of the comparison in the image processing unit 20 is below a threshold, the system control unit 50 determines that the image is an original image, and when the difference exceeds the threshold, the system control unit 50 determines that the original image has been edited. In this way, even when there are a plurality of pieces of history information 207, it is possible to determine that the image to be judged for authenticity assurance is an original image according to the difference.

[0039] Although the preferred embodiments of the present invention have been described above, the present invention is not limited to the above-mentioned embodiments, and various modifications and changes are possible within the scope of the gist of the present invention. The present invention can also be realized by supplying a program that realizes one or more functions of the above-mentioned embodiments to a system or device via a network or storage medium, and having one or more processors of a computer in the system or device read and execute the program. The present invention can also be realized by a circuit (e.g., ASIC) that realizes one or more functions.

[0040] The disclosure of each embodiment includes the following configurations, methods, and programs. (Configuration 1) An acquisition means for acquiring an image; an information determining means for determining whether or not the image acquired by the acquiring means has been added with history information relating to the history of editing performed on the image; a detection means for detecting the number of pieces of history information when it is determined that the history information has been added as a result of the determination by the information determination means; an authenticity assurance determination means for determining the authenticity of the image in a stepwise manner based on a result of the detection by the detection means; and a notification unit that notifies a result of the determination made by the authenticity assurance determination unit. (Configuration 2) The image processing device according to Configuration 1, further comprising: a correctness determination means for determining whether the history information is correct when the information determination means determines that the history information has been added; and when the correctness determination means determines that the history information is correct when the detection means determines that the number of pieces of history information is one, the authenticity assurance determination means determines that the image is authentic and that the image is original when the detection means determines that the number of pieces of history information is not one. (Configuration 3) The image processing device according to Configuration 2, characterized in that when the authenticity determination means determines that the history information is incorrect as a result of the determination by the authenticity determination means, the authenticity assurance determination means determines that the image is not authentic. (Configuration 4) The image processing device described in Configuration 2 or 3, characterized in that when the detection means detects multiple pieces of history information as a result of detection, the authenticity assurance determination means is capable of comparing the history information with each other and determining whether or not at least one edit has been performed based on the result of the comparison. (Configuration 5) The image processing device described in Configuration 4, wherein the authenticity assurance determination means, as a result of comparing the history information, determines that the at least one edit has not been performed if the difference between the history information is smaller than a predetermined value, and determines that the at least one edit has been performed if the difference between the history information is equal to or greater than the predetermined value. (Configuration 6) The image processing device according to any one of claims 2 to 5, characterized in that, when it is determined that the image is an original, the image is an original image captured by an imaging device. (Configuration 7) The history information includes a hash value, 7. The image processing device according to any one of configurations 2 to 6, wherein the authenticity determining means determines whether the history information is authentic by using the hash value. (Configuration 8) An image processing device described in any one of configurations 2 to 7, characterized in that when the information judgment means judges that the history information has not been added, the authenticity assurance judgment means judges that the authenticity of the image cannot be determined. (Configuration 9) The image processing device according to any one of configurations 1 to 8, further comprising an imaging means for capturing the image. (Method 1) A method for controlling an image processing device that performs image processing, comprising the steps of: An acquisition step of acquiring an image; an information determination step of determining whether or not history information regarding a history of editing performed on the image is added to the image acquired in the acquisition step; a detection step of detecting the number of pieces of history information when it is determined in the information determination step that the history information is added; an authenticity determination step of determining the authenticity of the image in stages based on a result of the detection in the detection step; a notification step of notifying a result of the determination in the authenticity determining step. (Program 1) A program for causing a computer to execute each of the means of the image processing device according to any one of configurations 1 to 9. [Explanation of symbols]

[0041] 20 Image processing section 50 System control section 70 Metadata Generation and Analysis Section 72 Hash value generator 73 Hash value comparison section 100 Digital Camera 207 History Information 300 Image processing device

Claims

1. An acquisition means for acquiring an image; an information determination means for determining whether or not history information regarding a history of editing performed on the image is added to the image acquired by the acquisition means; a detection means for detecting the number of pieces of history information when it is determined that the history information has been added as a result of the determination by the information determination means; an authenticity assurance determination means for determining the authenticity of the image in a stepwise manner based on a result of the detection by the detection means; and a notification unit that notifies a result of the determination made by the authenticity assurance determination unit.

2. The image processing device according to claim 1, further comprising: a correctness determination means for determining whether the history information is correct when the information determination means determines that the history information has been added; and when the correctness determination means determines that the history information is correct when the correctness determination means determines that the history information is correct, the authenticity assurance determination means determines that the image is authentic and that the image is an original if the result of detection by the detection means indicates that the number of pieces of history information is one, and determines that the image is authentic and that the image has been edited if the result of detection by the detection means indicates that the number of pieces of history information is not one.

3. 3. The image processing apparatus according to claim 2, wherein, when the authenticity determining means determines that the history information is incorrect, the authenticity assurance determining means determines that the image is not authentic.

4. The image processing device according to claim 2, characterized in that, when a plurality of pieces of history information are detected as a result of detection by the detection means, the authenticity assurance determination means is capable of comparing the history information with each other and determining whether or not at least one edit has been performed based on the result of the comparison.

5. The image processing device according to claim 4, characterized in that the authenticity assurance determination means determines that the at least one edit has not been performed if, as a result of comparing the history information, the difference between the history information is smaller than a predetermined value, and determines that the at least one edit has been performed if the difference between the history information is equal to or greater than the predetermined value.

6. 3. The image processing apparatus according to claim 2, wherein when the image is determined to be an original, the image is an image originally captured by an image capturing device.

7. The history information includes a hash value, 3. The image processing apparatus according to claim 2, wherein the authenticity determining means determines whether the history information is authentic by using the hash value.

8. 3. The image processing device according to claim 2, wherein, when the information determination means determines that the history information has not been added as a result of the determination, the authenticity assurance determination means determines that the authenticity of the image cannot be determined.

9. The image processing apparatus according to claim 1 , further comprising an image capturing unit for capturing the image.

10. A method for controlling an image processing device that performs image processing, comprising the steps of: An acquisition step of acquiring an image; an information determination step of determining whether or not history information regarding a history of editing performed on the image is added to the image acquired in the acquisition step; a detection step of detecting the number of pieces of history information when it is determined in the information determination step that the history information is added; an authenticity determination step of determining the authenticity of the image in stages based on a result of the detection in the detection step; a notification step of notifying a result of the determination in the authenticity determining step.

11. 2. A program for causing a computer to execute each of the means of the image processing apparatus according to claim 1.

Images