JP4328610B2 - Imaging device - Google Patents

Description

  The present invention relates to an image processing technique capable of changing parameters relating to the image quality of a digital image.

  Image recording methods in digital cameras include “JPEG method” and “RAW method”.

  The JPEG method is related to image quality such as preset development parameters (white balance, hue, color density, contrast, sharpness, image size, etc.) of digital image data of a subject imaged by an image sensor (CCD sensor, CMOS sensor, etc.). This is an image recording method in which the processed image data is compressed by the JPEG method, and the image data compressed by the JPEG method is recorded on a recording medium (such as a memory card) together with the additional data. Hereinafter, the compressed image data generated according to the JPEG method is referred to as JPEG image data.

  The RAW method is a predetermined lossless compression method in which digital image data of a subject imaged by an image sensor (CCD sensor, CMOS sensor, etc.) is compressed by a predetermined lossless compression method (for example, a combination of DPCM and Huffman coding). This is an image recording method in which the image data compressed in step 1 is recorded on a recording medium (such as a memory card) together with the additional data. Hereinafter, the compressed image data generated according to the RAW method is referred to as RAW image data. Unlike the JPEG method, the RAW method does not process image data in accordance with preset development parameters (parameters relating to image quality such as white balance, hue, color density, contrast, sharpness, and image size). Instead, the preset development parameters are recorded together with the RAW image data as additional data of the RAW image data.

  On the other hand, since it is easy to tamper with digital data so that no trace remains, reliability as evidence of the captured digital image may be a problem. Such a problem is unlikely to occur as long as it is a hobby shooting by a general user, but becomes a big problem in shooting required for business or legal purposes, such as a recorded photo at a construction site. Another problem is that the rights of the copyright holder of the image are not sufficiently protected because digital data can be copied and distributed very easily.

  Therefore, there is a great expectation for a digital camera that can enhance the evidence ability of a photographed digital image and protect the copyright. Therefore, in recent years, there have been proposed digital cameras having a function of adding verification data for verifying that the digital data has not been altered to the digital data recorded by the digital camera (for example, Patent Document 1 and Patent Document). 2).

  However, when determining whether or not there is a modification based on the verification data, for example, when the user changes a parameter relating to image quality with respect to the image data of the RAW recording method to which the verification data is added, the parameter area of the RAW recording method file Since the image data itself is automatically overwritten, it is determined that the entire RAW recording image data has been modified, even though the image data itself has not been modified. As a result, the user may not be able to use an image whose parameters are changed according to his / her preference.

In such a case, even if the digital data is acquired by the RAW recording method with the corner digital camera, the user cannot edit according to his / her preference, so the merit of the digital camera is diminished. .
US Pat. No. 5,499,294 Japanese Patent Application Laid-Open No. 9-2000730

  As described above, conventionally, in order to prevent unauthorized modification of digital data, there is a problem that the merit inherent to the digital camera is sacrificed.

  Accordingly, an object of the present invention is to enable data alteration prevention while making use of the merit of a digital camera by making it possible to change image quality parameters for acquired digital data.

The present invention for solving the above-described problem is an imaging apparatus, which generates imaging data and verification data for verifying whether or not the image data has been modified based on image data acquired by the imaging means Means for adding the verification data to the image data, and recording the image data on a recording medium together with parameter information for adjusting the image quality of the image data, and adding the verification data to the image data Means for setting whether or not, change accepting means for accepting a change of a parameter included in the image file recorded on the recording medium, and an image including the changed parameter for the image file to which the verification data is added Setting means for setting recording prohibition of the file, and when the recording prohibition is set by the setting means, the verification Recording of the image file including the changed parameter is prohibited for the image file to which data has been added, and if the recording prohibition is not set, the change has been made for the image file to which the verification data has been added. Control means for recording an image file including parameters.

  According to the present invention described above, it is possible to prevent data modification while taking advantage of the digital camera by making it possible to change the image quality parameter of the acquired digital data.

  Hereinafter, preferred examples for carrying out the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 is a diagram illustrating a configuration of a back surface of a digital camera 100 that is an example of an imaging apparatus according to an embodiment of the present invention. As shown in FIG. 1, a digital camera 100 has an optical finder 101, a rear electronic dial 102 for inputting an up / down signal, a color monitor 103 for displaying a photographed image and a graphical user interface (GUI), Various setting button groups 104 and a memory card slot 105 for storing a memory card for storing photographed image data are provided.

  FIG. 2 is a diagram illustrating a configuration of the upper surface portion of the digital camera 100. As shown in FIG. 2, the digital camera 100 has an LCD (Liquid Crystal Display) 106 for displaying shooting information, an upper surface electronic dial 107 for inputting up / down signals, and various settings for setting the shooting operation of the camera. Setting button groups 108 to 110, a release button 111, and the like are provided.

  In this embodiment, various settings relating to development parameters can be input / changed by the user of the digital camera 100 using the setting button 104 and the rear electronic dial 102 while viewing the GUI displayed on the color monitor 103. In the present embodiment, the development parameter means a parameter related to the image quality of a digital image, and more specifically, the parameters related to white balance, hue, color density, contrast, and sharpness of the digital image all correspond to development parameters. In the description of this embodiment, processing for adjusting (changing) the image quality of a digital image using one or more development parameters is referred to as development processing for the sake of simplicity. That is, this development processing is processing for adjusting the image quality of a digital image by adjusting and changing pixel value information (RAW image) acquired by an image sensor such as a CCD based on the development parameters.

  Next, an example of the hardware configuration of the digital camera 100 which is the imaging apparatus of the present embodiment will be described with reference to FIG. FIG. 6 is a block diagram illustrating an example of a hardware configuration of the digital camera 100 corresponding to the present embodiment.

  Reference numeral 201 denotes an image sensor (for example, a CCD sensor or a CMOS sensor). A subject image is formed on the imaging surface by a release operation, and the image signal is output as an analog pixel signal. An A / D converter 202 converts an analog pixel signal output from the image sensor 201 into a digital pixel signal. The image data converted into a digital signal by the A / D converter 202 is the RAW image data in this embodiment. This RAW image data is stored in the DRAM 208 and displayed on the display unit 205 as necessary. When the RAW image data is stored in the DRAM 208, the development parameters set at the time of imaging are read from the memory 206 and added as the header of the image file.

  A development processing unit 203 develops RAW image data according to development parameters set by default or set by a user. The developed image data is stored again in the DRAM 208 and displayed on the display unit 205 as necessary. Reference numeral 204 denotes a control unit that controls various devices in accordance with a program stored in the memory 206 in advance. A display unit 205 reproduces and displays image data and displays shooting information. Specifically, the color monitor 103 and the LCD 106 correspond to the display unit 205.

  206 stores a program for controlling the entire digital camera, and also sets development parameter settings, settings related to the recording method and compression ratio, verification data generation function settings received from the user, and settings when the development parameters are changed. Is a memory for storing. The memory 206 is composed of a readable / writable storage medium such as a flash memory or an EEPROM.

  Reference numeral 207 denotes an operation unit that accepts settings regarding development parameters, inspection data, changed parameter storage formats, and shooting information from the user, and selection of images to be displayed on the display unit 205. Specifically, the rear electronic dial 102, the rear setting button 104, the upper electronic dial 107, the various setting button groups 108 to 110, the release button 111, and the like in the digital camera 100 correspond to the operation unit 207. A DRAM 208 stores RAW image data and compressed image data. Various image data stored in the DRAM 208 is written to the removable memory card 213 via the memory card interface 210.

  A serial interface 209 is connected to an external device such as a network or the image reproducing apparatus 102 via the serial bus 212 and distributes image data. A memory card interface 210 connects the memory card 213 and the digital camera 100. A serial bus 211 connects the blocks to each other and transfers information between the blocks. Reference numeral 212 denotes a serial bus for transferring information by connecting the image generating apparatus 101 to a network or an externally connected device.

  The memory card 213 is a storage unit that stores an image file in which development parameters are added to RAW image data, and compressed image data, and includes, for example, a flash memory. A compression processing unit 214 converts image data developed by the development processing unit into image data in a compression format such as JPEG image data.

  When verification data is generated, verification data is generated for the RAW image data stored in the DRAM 208, and is written to the memory card 213 together with the verification data. The image data can be output to the serial bus 212 via the serial I / F 209, and the image data can be easily distributed on the network. When the development parameters of the RAW image data are changed, the RAW image data read from the memory card 213 via the memory card I / F 210 is stored in the DRAM 208 and displayed on the display unit 205.

  FIG. 3 is a diagram showing an example of a GUI (Graphical User Interface) displayed on the color monitor 103 when setting of parameters including development parameters is received from the user. When the user operates the back operation button 104 of the digital camera 100, a screen as shown in FIG. 3 is displayed on the color monitor 103, and each parameter including development parameters can be changed. At this time, the control unit 204 checks whether or not the verification data is added to the RAW image data, and operates in the operation mode set by the setting when changing the development parameter shown in FIG. 5 according to the presence or absence of the verification data.

  The user can input and change development parameters and recording methods using the setting button 104 and the rear electronic dial 102 in accordance with the contents of the screen displayed on the color monitor 103. In FIG. 3, 301 to 307 displayed on the color monitor 103 represent types of parameters that can be set by the user, and include development parameters 301 to 305, a recording method 306, and a compression rate 307. Here, the recording method 306 is a parameter for setting the format of digital image data acquired when the digital camera 100 performs imaging, and accepts selection of either a RAW image or a JPEG image. The compression rate 307 is a parameter for setting the compression rate when a JPEG image is selected by the recording method 306. The setting items shown in FIG. 3 are merely examples, and the embodiment of the present invention is not limited to displaying the development parameters. Other parameters for image quality adjustment are displayed on the color monitor 103. Also good. The setting items input / changed here are not set for each image, but are set in common for all images acquired by the digital camera 100, and the setting result is stored in the memory 206. .

  Each development parameter is associated with the setting contents related to the parameter. For example, as for the white balance 301, four “Auto”, “Sunny”, “Cloudy”, and “Light bulb” are displayed as the setting contents. Regarding such setting contents, contents selected by the user or selected by default are indicated by a frame line 308. Therefore, “Auto” is selected for “White Balance”, and “Red” is selected for Hue 302.

  In FIG. 3, “JPEG” is selected for the recording method 306, but in the shooting performed at the time of this setting, the image data is developed using the development parameters based on the setting contents as shown in FIG. 3. The image data is developed at, converted to JPEG image data by the compression processing unit 214, and then recorded on the memory card 213. The JPEG image data is generated by subjecting an analog image signal captured by an image sensor such as a CCD or CMOS to development processing and compression processing using the above-described development parameters. Development parameters cannot be changed for image data.

  On the other hand, in shooting performed when the recording method 306 is set to “RAW”, the captured image data is composed of pixel values (digital values) acquired by each pixel of a CCD or CMOS image sensor, and color The development parameters set on the monitor 103 are not reflected in the image data. That is, the image data is not subjected to the development process, and each development parameter stored in the memory 206 is added and recorded as one image file on the memory card 213.

  The image file of the RAW image data recorded on the memory card 213 is read from the memory card 213 to a storage device such as a hard disk in the computer by using the development parameters in the image file, in the digital camera 100, or by a personal computer or the like. If it is issued, development processing and compression processing can be performed in the personal computer. In other words, using the parameters, it is possible to convert RAW image data into compressed data such as JPEG image data. At this time, the development parameters in the image file can be further changed in the digital camera 100 or personal computer.

  Next, generation of verification data will be described. The setting of verification data can also be input / changed using the setting button 104 and the rear electronic dial 102 while the user looks at the GUI displayed on the color monitor 103. The verification data is generated by generating a hash value (digest data) of the RAW image data using the hash function H and performing arithmetic processing with the secret key K held in the digital camera. As the hash function H, MD-2MD-5, SHA-1, RIPEMD-128, RIPEMD-160, and the like are known. The secret key K corresponds to a secret key in a public key cryptosystem (such as RSA cryptography).

  FIG. 4 is a diagram illustrating an example of a graphical user interface (GUI) displayed on the color monitor 103 when performing settings relating to generation of verification data. Here, “verification data generation (401)” is displayed as an item for accepting settings from the user, and “on (402)” and “off (403)” are displayed as the contents of the setting items. In the setting example shown in FIG. 4, “ON” 402 is selected as the verification data generation function 401. In this case, verification data is generated for the RAW image data based on the verification data generation method and added to the image file. The verification data generation function setting is not set for each image, but is set as content common to all images acquired by the digital camera 100, and the setting result is stored in the memory 206.

  FIG. 5 shows a graphical user interface (GUI) displayed on the color monitor 103 for setting the storage format of the changed development parameter when the development parameter is changed for the RAW image data stored in the memory card 213. It is a figure which shows an example. In the digital camera 101 corresponding to the present embodiment, the operation mode for the RAW image data to which the verification data is added (file with verification data 501) and the operation mode for the RAW image data to which the verification data is not added (file with no verification data). 502) can be selected. The operation mode is not set for each image, but is set as an operation mode common to all images acquired by the digital camera 100, and the setting result is stored in the memory 206.

  Among the items for accepting settings from the user, in the verification data file 501, the storage format of overwriting prohibition 503, overwriting 504, and saving 505 as a separate file is displayed as the setting contents. Accept the selection.

  When the overwrite saving prohibition 503 is selected in the GUI of FIG. 5, the development parameters changed for the RAW image data stored in the memory card 213 are not overwritten on the original image data, and the original image data is No change at all. That is, the image data read from the memory card 213 to the DRAM 208 is discarded as it is. Therefore, this setting mode is effective in that the user can prevent the image from being erroneously altered when the user wants to retain copyright information or to ensure the reliability of the evidence photograph.

  Next, when the overwrite save 504 is selected, the RAW image data stored in the memory card 213 is once read into the DRAM 208 and the development parameters are overwritten, and then the memory card 213 is passed through the memory card interface 210. Since the image data stored in is overwritten, the changed development parameter is retained, but the image data is altered.

  Further, when save 505 is selected as a separate file, the RAW image data stored in the memory card 213 is once read into the DRAM 208 and the development parameters are overwritten, and then the memory card via the memory card interface 210. Since the image data is written in the image 213 as another image data, the original image data is not changed at all, and the changed development parameter is held in the duplicated image data. This setting mode is effective when the user wants to save the image data to ensure the reliability as evidence, and at the same time to change the development parameters arbitrarily for private use to obtain the desired image output. is there.

  On the other hand, in the non-verification data file 502, the user can accept the selection of the save format of either the overwrite save 506 or the save as another file 507 from the user. Here, when the overwrite save 506 is selected, the RAW image data stored in the memory card 213 is once read into the DRAM 208 and the development parameters are overwritten, and then the memory card 213 is passed through the memory card interface 210. Since the image data stored in is overwritten, the changed development parameters are retained. This setting mode is effective when the user wants to store as much image data as possible in consideration of the capacity of the memory card 213.

  Next, when the save 507 is selected in another file, the RAW image data stored in the memory card 213 is once read out to the DRAM 208 and the development parameters are overwritten. Since the image data is written on the card 213 as another image data, the original image data is not changed at all, and the changed development parameter is held in the duplicated image data. This setting mode is effective when the user wants to save image data to which default development parameters are added and image data to which development parameters customized by the user himself are added.

  In the setting example shown in FIG. 5, overwriting saving prohibition 503 is set as the operation mode for the verification data existence file 501, that is, the RAW image data to which the verification data is added. The operation mode for the verification data no file 502, that is, the RAW image data to which no verification data is added is set to overwrite save 506.

  Next, in the digital camera 100 corresponding to the embodiment of the present invention, a process (development parameter change process) when changing the development parameter of RAW image data will be described with reference to the flowchart of FIG. FIG. 7 is a flowchart illustrating an example of the development parameter changing process executed by the digital camera 100 which is an example of the imaging apparatus according to the embodiment of the present invention.

  First, when the user operates the back setting button 104 of the digital camera 100 to start the playback operation, an image is played back on the back color monitor 103, and an image selection instruction from the user is accepted in step S301. The user operates the back setting button 104 and the back electronic dial 102 to select an image. Each time the rear electronic dial 102 is operated, the image displayed on the color monitor 103 is switched. Development parameters can be changed only when RAW image data is displayed on the color monitor 103.

  In step S302, a change in development parameter is received from the user. The user can input and change development parameters using the setting button 104 and the rear electronic dial 102.

  In step S303, it is determined whether or not the development parameter has been changed. If it is determined that the development parameter has not been changed ("NO" in step S303), the process proceeds to step S311 and the user selects another image. Determine if it was accepted. If no other image is selected and the back setting button 104 is operated (“NO” in step S311), the process ends in step S312. If another image has been selected (“YES” in step S311), the process returns to step S302 to accept development parameter changes.

  On the other hand, when it is determined that the development parameter has been changed (“YES” in step S303), the process proceeds to step S304, and it is determined whether verification data is added to the selected RAW image data. If it is determined that no verification data has been added (“NO” in step S304), in step S305, the operation mode in the verification data non-file 502 whose setting is received in the GUI as shown in FIG. 5 is determined. In this determination, when it is determined that the overwrite save 506 is set as the operation mode (“overwrite save” in step S305), the process proceeds to step S306, and the development included in the RAW image data read to the DRAM 208 is performed. After the parameter value is rewritten to a new setting value, the corresponding RAW image data stored in the memory card 213 is overwritten, and the RAW image data with the development parameter changed is saved.

  On the other hand, if save 507 as a separate file is set as the operation mode ("Save as separate file" in step S305), the process proceeds to step S307, and the development parameter included in the RAW image data read to the DRAM 208 is displayed. After the value is rewritten to a new setting value, the corresponding RAW image data stored in the memory card 213 is not overwritten, and the RAW image data with the development parameters changed is saved as a separate file.

  If it is determined in step S304 that the verification data has been added (“YES” in step S304), the process proceeds to step S308, and the operation mode in the verification data file 501 whose setting is received in the GUI as shown in FIG. Determine. In this determination, if it is determined that the overwrite save 504 is set as the operation mode (“overwrite save” in step S308), the process proceeds to step S309 and is included in the RAW image data read to the DRAM 208. After rewriting the value of the development parameter to a new setting value, the corresponding RAW image data stored in the memory card 213 is overwritten, and the RAW image data with the changed development parameter is saved. At this time, a warning display to the effect that the verification data becomes invalid may be displayed on the rear color monitor 103 before overwriting.

  When it is determined that save 505 is set as another operation mode (“Save as another file” in step S308), the process proceeds to step S310, and development included in the RAW image data read to the DRAM 208 is performed. After the parameter value is rewritten to a new setting value, the corresponding RAW image data stored in the memory card 213 is not overwritten, and the RAW image data with the development parameter changed is saved as a separate file. At this time, since verification data is not added to the newly created image file, the user can freely change the development parameters of the generated image file.

  If it is determined that the overwrite save prohibition 503 is set as the operation mode (“overwrite prohibition” in step S308), the RAW image data read to the DRAM 208 is discarded as it is and stored in the memory card 213. No changes are made to the corresponding RAW image data. Then, the process directly proceeds to step S311 to accept another image selection, or the process ends in step S312. When the overwrite saving prohibition 503 is set and the development parameter change is accepted, the user may be notified by displaying on the color monitor 103 that the overwrite saving prohibition is set.

  When the respective operations are completed in the above steps S306, S307, S309, and S310, the process proceeds to step S311 to select another image or the reproduction operation is ended in step S312.

  As described above, in the present invention, as the operation when the development parameter of “RAW image data” is changed, when verification data is added to “RAW image data”, “overwrite prohibited”, “overwrite save” ”And“ Save as a separate file ”can be selected, and when no verification data is added to“ RAW image data ”, two modes of“ Overwrite ”and“ Save as a separate file ”are available. Therefore, it is possible to prevent the user from modifying the image by mistake. Alternatively, the development parameters set by the user can be reliably saved in a file.

[Other Examples]
In the present embodiment described above, the digital camera is taken as an example of the imaging apparatus. However, the imaging apparatus to which the present invention is applicable is not limited to the digital camera, and has a camera unit such as a digital video camera or a scanner. Even an imaging device may be an electronic device capable of image processing other than a personal computer or a personal computer.

  In addition, the configuration of the present invention is not limited to the specific description in the above-described embodiments, and it is needless to say that various embodiments can be considered depending on the specifications of the imaging apparatus, the assumed user layer, and the like. .

  Another object of the present invention is to supply a storage medium (or recording medium) in which a program code of software that realizes the functions of the above-described embodiments is recorded to a system or apparatus, and the computer (or CPU or CPU) of the system or apparatus. Needless to say, this can also be achieved by the MPU) reading and executing the program code stored in the storage medium. In this case, the program code itself read from the storage medium realizes the functions of the above-described embodiments, and the storage medium storing the program code constitutes the present invention. Further, by executing the program code read by the computer, not only the functions of the above-described embodiments are realized, but also an operating system (OS) running on the computer based on the instruction of the program code. It goes without saying that a case where the function of the above-described embodiment is realized by performing part or all of the actual processing and the processing is included.

  Further, after the program code read from the storage medium is written in a memory provided in a function expansion card inserted into the computer or a function expansion unit connected to the computer, the function expansion is performed based on the instruction of the program code. It goes without saying that the CPU or the like provided in the card or the function expansion unit performs part or all of the actual processing, and the functions of the above-described embodiments are realized by the processing.

It is a figure which shows the structure of the back part of the digital camera which is an example of the imaging device in the Example of this invention. It is a figure which shows the structure of the upper surface part of the digital camera which is an example of the imaging device in the Example of this invention. 3 is a diagram illustrating an example of a GUI (Graphical User Interface) displayed on the color monitor 103. FIG. 3 is a diagram illustrating an example of a GUI (Graphical User Interface) displayed on the color monitor 103. FIG. 3 is a diagram illustrating an example of a GUI (Graphical User Interface) displayed on the color monitor 103. FIG. It is a block diagram which shows an example of the hardware constitutions of the digital camera which is an example of the imaging device in the Example of this invention. 6 is a flowchart illustrating an example of development parameter change processing executed by a digital camera that is an example of an imaging apparatus according to an embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Digital camera 101 Optical viewfinder 102 Back surface electronic dial 103 Back surface color monitor 104 Back surface various setting button group 105 Memory card slot 106 LCD
107 Upper-side electronic dials 108 to 110 Upper-side various setting buttons 111 Release button 201 Image sensor 202 A / D converter 203 Development processing unit 204 Control unit 205 Display unit 206 Memory 207 Operation unit 208 DRAM
209 Serial interface 210 Memory card interface 211 Data bus 212 Serial bus 213 Memory card

Claims (1)

Imaging means;
Generating means for generating verification data for verifying the presence or absence of alteration of the image data based on the image data acquired by the imaging means;
Recording means for adding the verification data to the image data and recording the image data as an image file together with parameter information for adjusting the image quality of the image data;
Means for setting whether to add the verification data to the image data;
Change accepting means for accepting a change in parameters included in the image file recorded on the recording medium;
Setting means for setting prohibition of recording of the image file including the changed parameter for the image file to which the verification data is added;
When the recording prohibition is set by the setting unit, the recording of the image file including the changed parameter is prohibited for the image file to which the verification data is added, and the recording prohibition is not set Control means for recording an image file including the changed parameter for the image file to which the verification data is added;
An imaging apparatus comprising:

Images