JP2009200577A - Image recording device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To easily transfer an image while preventing an image recorded in a memory card from being let out when an image recording device is stolen or lost. <P>SOLUTION: A digital camera 10 obtains compressed image data in JPEG format through an imaging unit 20, an image processing unit 21, and a JPEG processing unit 25. When encryption is set, a ZIP processing unit 25 encrypts the compressed image databased upon a designated password, and creates a compression (ZIP format) folder in a memory card loaded in a memory card unit 26 to record a photographed image, so security is ensured right after photography. When encryption is not set, the compressed image data in JPEG format are recorded in the memory card as they are. The encrypted compression folder is decrypted on a general PC only with the password. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

    The present invention relates to an image recording apparatus such as a digital camera, and more particularly to an image recording apparatus that encrypts a photographed image with a password and records it on a memory card.

  In an image recording apparatus such as a digital camera, usually, a captured image is recorded as a file on a memory card inserted in a memory slot provided in the digital camera. Then, by connecting this digital camera to a PC (personal computer) via a USB interface, or removing the memory card from the memory slot and mounting it on a card reader built in the PC, the image file is stored on the PC. It has a configuration that can be used. For this reason, when a digital camera or a memory card on which an image is recorded is stolen or lost, image data may be leaked, and countermeasures are required.

As an example, when the correction information for identifying a defective pixel is applied as information unique to the digital camera, the image is encrypted and recorded on a memory card, and the image is viewed via the PC, the viewing is permitted. There is one in which a predetermined application is incorporated in (see Patent Document 1).
JP 2003-333519 A

  However, in the above-mentioned digital camera, a predetermined application is incorporated in a PC that permits browsing, and while higher security can be maintained, a memory card is sent to a remote place to browse images. In this case, it is necessary to provide this application at the same time.

  Of course, if you don't have an encryption function like an ordinary digital camera, you must encrypt the image file in advance to cope with theft or loss of the memory card during transportation. Must be done on a PC. In this case, it is necessary to pay sufficient attention to theft or loss of the digital camera and memory card immediately after shooting until immediately before the encryption work.

  The image recording apparatus according to claim 1, wherein the digital image data obtained from the analog image signal output from the solid-state imaging device is compressed using image compression, and the compressed image data is output as compressed image data. Encryption means for encrypting image data and outputting it as encrypted image data; File recording means for recording the encrypted image data on a removable recording medium as a data file; and volatile memory for storing the compressed image data The encryption unit performs a ZIP compression process based on a password, and the file recording unit generates a ZIP compressed folder in the recording medium and records the encrypted file. It is characterized by doing.

  The image recording apparatus according to claim 2, further comprising image display means for displaying the digital image data, wherein the image display means selects a file in a ZIP compressed folder in the recording medium. When the image is reproduced, if there is unencrypted compressed image data corresponding to the file in the memory unit, the compressed image data in the memory unit is used to reproduce the image. .

  According to the present invention, since a photographed image can be recorded directly on the memory card in the “compressed (ZIP format) folder” format inside the image recording apparatus, the risk of leakage of image data is greatly reduced. be able to. The format of this data is that of the files that are standard equipment in Microsoft Windows XP (registered trademark) and Windows Vista (registered trademark), which are considered to be the most popular OS (operating system) for PCs. Because it is compatible with compression / decompression tools, it is possible to decrypt the image only with a password in many environments, which can greatly enhance the convenience.

  Further, when an image captured by the image recording apparatus is reproduced on a display unit provided in the main body and the image is encrypted and recorded on a memory card, the image is recorded in a volatile memory inside the image recording apparatus. If compressed image data before encryption exists, the image is reproduced using the compressed image data, so that the image can be viewed quickly. This configuration is suitable for security because data on the volatile memory is lost when the power is turned off.

  Hereinafter, an image recording apparatus of the present invention will be described in detail based on preferred embodiments shown in the accompanying drawings. In this embodiment, the case where the image recording apparatus of the present invention is applied to a digital camera will be described as a representative example.

  FIG. 1 is a block diagram illustrating a configuration example of a digital camera. As shown in the figure, the digital camera 10 includes an imaging unit 20, an image processing unit 21, a memory unit 22, a display unit 23, a JPEG processing unit 24, a ZIP processing unit 25, a memory card 26, a CPU 27, an operation unit 28, A bus 30 is provided.

  The imaging unit 20 includes an imaging optical system, a solid-state imaging device such as a CCD image sensor, a drive circuit, an amplifier, an A / D converter, and the like (not shown). The CCD image sensor is a two-dimensional CCD sensor, and charges accumulated by input light are output by a drive signal from a drive circuit. This output signal is further amplified by an amplifier, digitized by an A / D converter, and output from the imaging unit.

  The image processing unit 21 receives the digital signal transferred from the imaging unit 20 and performs digital image processing such as noise removal processing, sharpening processing, density correction processing, and color signal processing, as digital image data together with the synchronization signal. Output.

  The memory unit 22 is composed of a volatile memory such as a large-capacity SDRAM, and is used as a work memory for the CPU 27 as well as a storage area for digital image data output from the image processing unit 21.

  The display unit 23 includes an LCD (Liquid Crystal Display) (not shown), and performs preview display of a captured image and reproduction display of a recorded image based on the input digital image data signal. The LCD can also display various data such as character / numeric information at the time of password setting, the current number of images that can be captured, and the date and time of image capture, either alone or superimposed on the image.

  The JPEG processing unit 24 performs compression processing on the above-described digital image data according to a JPEG (Joint Photographic Experts Group) format, and generates compressed image data. JPEG is one of the methods for compressing digital data of still images, and generally performs lossy compression using DCT (Discrete Cosine Transform). The same processing is performed. Also, a process of decompressing the compressed image data and returning it to the original digital image data is performed.

  The ZIP processing unit 25 performs ZIP compression processing on the compressed image data according to the specified password. Note that ZIP is one of the file compression formats, and is known to perform lossless compression. The ZIP processing unit 32 is used in the “compression (ZIP format) folder” that is standard in Windows XP and Windows Vista. It is configured to generate files that are compatible with Note that a password is not necessarily required for the ZIP compression process, but in the present embodiment, a ZIP compression process with a password is used for the purpose of encryption rather than reduction of the data amount. In fact, even if the compressed image data after the JPEG format is subjected to the ZIP compression process, the file size is hardly reduced. The ZIP processing unit 25 also performs a process of decompressing the ZIP compressed data and returning it to the original data. For details of the ZIP compression algorithm, see, for example, http: // www. pkware. com / documents / casestudios / APPNOTE. It is disclosed in TXT.

  The memory card unit 26 mounts a removable memory card such as an SD card or a compact flash (registered trademark) through a memory slot (not shown), and records a file. The memory card is composed of a non-volatile memory such as a flash memory, and can be read and written via a built-in PC or an external card reader.

  In addition to the CPU core, the CPU 27 has a built-in flash memory (not shown) for holding a system program for controlling the operation of the digital camera 10 and a data table, and the like, and accesses the memory unit 22. . In addition, an operation signal from the operation unit 28 including a shutter button and the like is input, and input to each unit of the imaging unit 20, the image processing unit 21, the display unit 23, the JPEG processing unit 24, the ZIP processing unit 25, and the memory card unit 26 is input. Control of output and data transfer processing between each unit is performed using the bus 30.

  The operation unit 28 includes a power switch, a shutter button, a menu dial, an arrow key, and the like (not shown), inputs information such as buttons operated by the user, and transfers the information to the CPU 27. The menu dial is a rotary switch, for example, and switches between a shooting mode for shooting, a playback mode for confirming and displaying a shot image, a setting mode for setting shooting conditions, a password, and the like. The arrow key is used for selecting an image to be displayed in the reproduction mode, and for selecting a character displayed on the display unit for setting a password. Note that the password may be set or input by photographing a printed one-dimensional or two-dimensional bar code or handwritten character and the CPU 27 recognizing the information.

  The operation of the digital camera 10 configured as described above will be described below with reference to the flowchart shown in FIG.

  The user turns on the digital camera 10 with the power switch of the operation unit 28 (S101). Before photographing with the digital camera 10, first, the operation unit 28 is operated to set a password for encrypting and storing the image. Specifically, the setting mode is selected by operating the menu dial (S102). Then, while confirming the display on the display unit 23, by operating the arrow keys of the operation unit 28, alphabets and numbers can be selected, and a password consisting of a predetermined number of characters is set (S103). Note that the display of the password on the display unit 23 disappears in a short time after the setting in order to prevent the leakage of the password due to peeping of others.

  The determined password is recorded and saved in a flash memory inside the CPU 27 and is used for a photographed image. However, as long as the password is saved, it is not necessary to set it every time. Also, after setting the password, it is set whether or not encryption is necessary for the image to be taken (S104). Here, first, it is assumed that encryption is unnecessary.

  Next, the shooting mode is selected by operating the menu dial (S105). When the photographing mode is entered, a digital signal based on the image photographed by the imaging unit 20 is transferred to the image processing unit 21 and subjected to digital image processing such as noise removal processing, sharpening processing, density correction processing, and color signal processing. Thus, it is output as digital image data together with the synchronization signal, becomes non-compressed digital image data, and is transferred to a predetermined area of the memory unit 22 and stored.

  The digital image data in the memory unit 22 is sent to the display unit 23 and displayed on the LCD. During the shooting mode, image signals are repeatedly transferred from the image capturing unit 20 to the image processing unit 21, the memory unit 22, and the display unit 23, so that the image is displayed on the LCD as a preview almost in a moving image. Note that the image being displayed in the preview is not recorded on the memory card, and the image processing in the image processing unit is sufficient to confirm whether the user appropriately captures the shooting target. Alternatively, the processing speed may be simplified and a low resolution corresponding to the resolution of the LCD may be used.

  The user captures an image while confirming the LCD and presses the shutter button to execute the image capturing (S106). As a result, the signal captured by the image capturing unit 20 is transferred to the image processing unit 21 again, subjected to processing such as noise removal and color conversion, and becomes non-compressed digital image data. It is transferred to the area and stored (S107). Further, this image is continuously displayed on the LCD for a certain period of time in order to confirm the photographed image of the user.

  Then, the image data stored in the memory unit is converted into compressed image data in the JPEG format by the JPEG processing unit 24 and stored in a storage area at another position in the memory unit 22 (S108). . The storage area has a predetermined size and can store a plurality of data. By repeating the shooting, the oldest data is sequentially overwritten and reused. To do. Here, the CPU 27 manages, in association with the file name recorded on the memory card, the data stored at which address in the memory unit and in what size the data is stored.

  In FIG. 1, the JPEG processing unit 24 is configured as a separate block from the CPU 27, but the CPU 27 may perform JPEG processing by itself.

  Here, it is referred to whether or not the digital camera 10 has been set to have encryption in S104 (S109). If the encryption is not set, the photographed image is recorded as a JPEG format file on the memory card of the memory card unit 26 as in the case of a normal digital camera (S111).

  On the other hand, when encryption is set, image data stored in the JPEG format is further subjected to ZIP processing based on the password stored in the flash memory inside the CPU 27 (S110), and the memory The card is stored as a ZIP compressed file (S111). As in the case of the JPEG processing unit 24, the ZIP processing unit 25 is configured as a block separate from the CPU 27, but the CPU 27 may perform the ZIP compression processing by itself.

  In the digital camera 10, the setting mode is used to set the presence / absence of encryption. In order to perform a simpler operation, two shutter buttons are provided on the operation unit 28 and which button is pressed. Thus, the recording with or without encryption may be switched.

  Here, the file structure inside the memory card is shown in FIG. It is assumed that the memory card is formatted with a general-purpose FAT file system so that it can be recognized from a normal PC.

  In the digital camera 10, when shooting is started, two folders of NOCRYPT and CRYPT are created under the root (¥) in the memory card immediately after formatting. If these folders already exist, they will not be created anew.

  First, when shooting is performed without performing encryption, 001FOLDER, which is an ordinary uncompressed folder, is created under NOCRYPT, and a JPEG-format image file P0010001. JPG is recorded. Then, when shooting is repeated, as long as an empty area is secured in the memory card, image files are further sequentially stored in this folder in P0010002. JPG, P0010003. JPG and file name are changed and recorded. If the file name is P0019999. When JPG is reached, 002FOLDER is created under the folder NOCRYPT, and P0020001. JPG, P0020002. JPG, P0020003. JPG and recording are performed.

  Here, P0010003. Under 001FOLDER under NOCRYPT. It is assumed that the setting of the digital camera 10 is changed so that the photographed image is encrypted after recording the JPG. Then, when shooting, the compressed folder 001FOLDER. ZIP is created, and this compressed folder 001FOLDER. The file P0010004. JPG is recorded. Thereafter, when photographing is repeated, 001FOLDER. In the ZIP, P0010005. JPG, P0010006. JPG,. . . Is stored in the same compressed folder.

  By the way, in order to view a file stored in the compressed folder created in this way on a PC in which Windows XP or Windows Vista is installed as an OS, the password must be entered when trying to open the file. You only need to enter the password for recording accordingly. Of course, it does not matter if the compressed folders are individually created so that each file (P0010004.JPG, P0010005.JPG, P0010006.JPG,...) Is included in one compressed folder. .

  In addition, when decompressing an encrypted file, the file name is assigned with a sequential number here so that it does not have the same file name as the file recorded without encryption, It is good also as a serial number individually. The file under 001FOLDER under CRYPT is P0019999. When JPG is reached, 002FOLDER. ZIP is created and 001FOLDER. Recording is performed in the same manner as in the case of a ZIP folder.

  Now, with respect to the formatted memory card, 10 images are encrypted and the first, second, third, seventh, and eighth images are photographed. Assume that the ninth and tenth images are taken. Then, for example, a file is stored in the memory card as shown in FIG.

  Here, the operation at the time of image reproduction will be described with reference to the flowchart shown in FIG. The mode of the digital camera is changed from the shooting mode (S201) to the playback mode (S202). Then, first, the tenth image is displayed as the latest photographed image, and the photographed image in the memory card can be selectively displayed by operating the arrow key (S203) (S204).

  Specifically, the file in the memory card is searched and it is determined whether or not the selected file is encrypted (S205). If the file has not been subjected to the ZIP compression process, the compressed image data based on the JPEG format is transferred to the memory unit 22 (S208), and then developed into the uncompressed digital image data by the JPEG processing unit 24 (S210). . The developed digital image data is displayed on the LCD by the display unit 23 (S211).

  On the other hand, if the selected file is encrypted in S205, it is first determined whether or not compressed image data in the JPEG format corresponding to the memory unit 22 remains (S206). In the SDRAM of the memory unit, a work area of the CPU 27, a storage area for uncompressed digital image data, a storage area for compressed image data, a storage area for encrypted image data, and the like are provided as shown in the memory map of FIG. It has been.

  Currently, when the 10th image is taken, the 1st and 2nd image data are overwritten by the 9th and 10th image data, respectively, and the 3rd to 10th image data remain. And Therefore, if the selected image remains in this, it is expanded from this data into uncompressed digital image data.

  If the data corresponding to the selected file does not remain in the memory unit 22, the encrypted data is transferred from the memory card to the memory unit 22 (S207). Further, the descrambling is further performed to restore the original compressed image data in the JPEG format (S209). Then, as in the case of an unencrypted image, the JPEG processing unit 24 develops the digital image data in an uncompressed format (S210). The restored image data is displayed on the LCD by the display unit 23 (S211).

  As described above, if compressed image data that has not been subjected to the ZIP process remains in the SDRAM of the memory unit 22, if the reference is made here, the descrambling process of the data subjected to the ZIP process becomes unnecessary, so that smooth It is suitable for browsing images. In this case, the image data on the SDRAM disappears when the power is turned off, which is preferable from the viewpoint of security.

  Digital cameras usually have a function that automatically turns off the power in a relatively short time of about several minutes after the last operation in order to prevent excessive battery consumption when not in use. is there. Therefore, in the case of the digital camera in the present embodiment, the SDRAM may be configured to maintain energization for a while for the above browsing operation even when the power is turned off.

  By the way, the digital camera 10 can display the encrypted image on the display unit 23 without requiring the input of a password. This is because the LCD of the display unit 23 has a low resolution, and the outflow of images from here is not taken into consideration. Therefore, if the resolution of the LCD is high, the encrypted image may be protected by applying a mosaic to the extent that only the photographer can judge. Of course, it is of course possible to adopt a specification that requires the input of a password for reproduction at the stage of the descrambling process of the ZIP process.

  Furthermore, although there is only one CRYPT folder in FIG. 3, for example, a plurality of folders such as CRYPT0 and CRYPT1 may be created, and a compressed folder may be stored under each folder. In this case, a separate password can be set for each folder, and a single digital camera can be shared by a plurality of people and each can hold an image to be kept secret.

As an application example of the present invention, for example, the present invention can be applied not only to a digital camera but also to other electronic devices capable of recording an image.

It is a control block diagram of the digital camera according to the present embodiment. It is a process flowchart regarding imaging | photography of the digital camera which concerns on this Embodiment. It is a figure which shows the folder structure of the memory card with which the digital camera which concerns on this Embodiment is mounted | worn. It is a figure which shows an example of the folder of the memory card with which the digital camera which concerns on this Embodiment is mounted | worn. It is a process flowchart regarding the reproduction | regeneration of the digital camera which concerns on this Embodiment. It is a figure which shows the memory map of the memory part of the digital camera which concerns on this Embodiment.

Explanation of symbols

10 digital camera, 20 imaging unit, 21 image processing unit, 22 memory unit, 23 display unit, 24 JPEG processing unit, 25 ZIP processing unit, 26 memory card unit, 27 CPU, 28 operation unit, 30 bus

Claims (2)

  Digital image data obtained from the analog image signal output from the solid-state imaging device is compressed using image compression and output as compressed image data; and the compressed image data is encrypted as encrypted image data An encryption unit for outputting, a file recording unit for recording the encrypted image data on a removable recording medium as a data file, and a memory unit including a volatile memory for storing the compressed image data, An image recording apparatus, wherein the encryption means performs ZIP compression processing based on a password, and the file recording means generates a ZIP format compressed folder in the recording medium and records the encrypted file.   2. The image recording apparatus according to claim 1, further comprising image display means for displaying the digital image data, wherein the image display means stores a file in a ZIP format compressed folder in the recording medium. When selecting and reproducing an image, if there is unencrypted compressed image data corresponding to the file in the memory unit, the image is reproduced using the compressed image data in the memory unit. An image recording apparatus.

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