JP4253206B2 - Digital camera - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to recording an image photographed with a digital camera onto an external recording medium.
[0002]
[Prior art]
Conventionally, an image captured by a digital camera is subjected to predetermined image processing based on control of a microcomputer built in the digital camera, and is stored in an external recording medium such as a RAM, an MMC card, or an SD card in the digital camera. To be recorded. A plurality of systems are known for communication between the microcomputer of the digital camera and the external recording medium. The SD card and the SPI mode are known as the communication method with the SD card, and the MMC mode and the SPI mode are known as the communication method with the MMC card. These modes have a data check function by CRC (Cyclic Redundancy Check). The CRC is an essential function in the SD mode and the MMC mode, and is an optional function in the SPI mode. By using CRC, it is possible to detect the occurrence of garbled data during transmission to an external recording medium (see Non-Patent Documents 1 and 2) .
[Non-Patent Document 1]
“Interface November 2001 issue”, CQ Publishing Co., Ltd., issued November 1, 2001, p. 168-171
[Non-Patent Document 2]
“Interface December 2001 issue”, CQ Publishing Co., Ltd., issued December 1, 2001, p. 137-139
[0003]
[Problems to be solved by the invention]
However, since CRC is an inspection method configured by a combination of complicated operations, if this function is implemented by software, the load on the software becomes extremely large. As a result, there is a problem that the data transmission speed to the external recording medium becomes slow. On the other hand, if the CRC function is not used in order to increase the speed of data transmission, data corruption cannot be detected, and the reliability of image data written on an external recording medium is lowered. That is, when an image photographed with a digital camera is written to an external recording medium, there is a problem that data cannot be transmitted at high speed and high reliability of the written data cannot be obtained.
[0004]
An object of the present invention is to solve the above-described problems, and an object of the present invention is to transmit a captured image of a digital camera to an external recording medium at a high speed and maintain the reliability of written image data.
[0005]
[Means for Solving the Problems]
A digital camera according to the present invention includes storage means for storing captured image data, image data recording means for transmitting and recording image data to an external recording medium, image data stored in the storage means, and external Comparing the image data recorded on the recording medium and checking the consistency thereof, and when the comparing means confirms that the image data of the storage means and the image data of the external recording medium are inconsistent, Image data recovery means for executing image data recording means and overwriting the image data of the storage means on the image data of the external recording medium, and processing of the comparison means and the image data recovery means when the digital camera after power-on is in a standby state And a control means for executing the above.
[0006]
Preferably, the storage position of the image data in the storage means, the storage position of the image data in the external recording medium, the data size of the image data, the presence / absence of execution of the processing of the control means, and the processing flag for recording the processing result The storage means stores the image data in association with the image data.
[0007]
Preferably, when the digital camera is in the above-described standby state, the control unit causes the processing of the comparison unit and the image data restoration unit to be executed repeatedly at all times.
[0008]
Preferably, the comparison unit performs the comparison process based on the storage position of the image data in the storage unit and the storage position of the image data in the external recording medium.
[0009]
As described above, according to the present invention, when the digital camera after power-on is in a standby state, the image data stored in the storage means and the image data recorded on the external recording medium are compared, and the two do not match. If it is confirmed that this is the case, the image data restoration means is executed. Therefore, it is possible to transmit the image data at a higher speed and to maintain the reliability of the image data on the external recording medium as compared with the case of checking for garbled data during the transmission of the image data.
[0010]
In the storage means, the storage position of the image data in the storage means, the storage position of the image data in the external recording medium, the data size of the image data, the presence or absence of execution of the processing of the control means, and the processing flag for recording the processing result Is stored in association with the image data in the storage means, so that the image data on the external recording medium is more accurately restored.
[0011]
When the digital camera is in a standby state after the power is turned on, the reliability of the image data on the external recording medium is further increased by repeatedly executing the processing of the above-described image data comparison unit and image data restoration unit.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram of a digital camera and an SD card to which an embodiment according to the present invention is applied. The microcomputer 10 of the digital camera 1 is a known processor with a built-in DSP dedicated to image processing that processes digital signals at high speed, and includes a CPU, RAM, ROM, and the like. The microcomputer 10 controls the entire digital camera 1. A photometric switch 20 and a release switch 30 are connected to the microcomputer 10, and respective on / off signals are inputted. When a release button (not shown) provided on the housing of the digital camera 1 is half-pressed, the photometry switch 20 is turned on, and photometry processing is executed based on the control of the microcomputer 10. When the release button is fully pressed, the release switch 30 is turned on and the photographing process is started.
[0013]
An optical image of the subject is formed on the light receiving surface of the CCD 40 by the photographing optical system 50. When the release switch 30 is turned on and the photographing process is started, the optical image of the subject is photoelectrically converted in the CCD 40 and input to the CDS / AD unit circuit 60 as an analog image signal. By the CDS / AD unit circuit 60, analog noise and reset noise generated from the CCD 40 are reduced, and the analog image signal is converted into a digital image signal. The digital image signal is input to the microcomputer 10.
[0014]
The digital image signal input to the microcomputer 10 is subjected to predetermined image signal processing. The digital image signal subjected to the image signal processing is stored in the RAM 70 as image data in units of one frame.
[0015]
An operation button switch group 80 that is linked to various operation buttons provided on the casing of the digital camera 1 is connected to the microcomputer 10. Based on the control of the microcomputer 10 according to the on / off state of the operation button switch group 80, writing of image data in the RAM 70 to the SD card 90, reproduction on the LCD 100, and the like are executed.
[0016]
The SD card 90 attached to the digital camera 1 via the connector 15 includes a controller 91 and a flash memory 92. Commands, image data, and the like are transmitted from the microcomputer 10 to the controller 91. The controller 91 executes processing according to the transmitted command and writes, for example, image data or the like to the flash memory 92. Note that communication between the microcomputer 10 and the controller 91 is performed in the SPI mode.
[0017]
A mode switch 110 that is linked to a mode dial provided on the casing of the digital camera 1 is connected to the microcomputer 10. The mode dial is a dial for selecting a shooting mode and a non-shooting mode. When the shooting mode is selected with the mode dial, the mode switch 110 is turned on.
[0018]
FIG. 2 is a flowchart showing a processing procedure of a main routine that is resident in the microcomputer 10 after the digital camera 1 is powered on. When the power of the digital camera is turned on, it is checked whether or not there is a key input in step S100. Presence / absence of key input is determined by checking the states of all the switches connected to the microcomputer 10. That is, when there is an on-state switch, it is determined that there is a key input.
[0019]
If it is confirmed in step S100 that there is a key input, the process proceeds to step S102. In step S102, it is checked whether the mode switch 110 is on and the shooting mode is set. If it is confirmed that the shooting mode is set, the process proceeds to step S104. In step S104, it is checked whether the release button has been fully pressed. Whether or not the release button has been fully pressed is determined by whether or not the key input is due to the release switch 30 being turned on. If it is confirmed that the release button is fully pressed, the process proceeds to step S106.
[0020]
In step S106, a photographing process is executed. That is, the subject image formed on the light receiving surface of the CCD 40 is photoelectrically converted, subjected to the above-described processing by the CDS / AD unit circuit 60, and predetermined image processing is performed by the microcomputer 10. Next, the process proceeds to step S108, and a RAM writing process is executed. In the RAM writing subroutine executed in the RAM writing process, the captured image data and recording information for recording the image data on the RAM 70 and the SD card 90 are stored in the RAM 70.
[0021]
FIG. 3 is a flowchart showing the processing procedure of the RAM writing subroutine. In step S200, image data for one frame is recorded in the RAM. Next, in steps S202 to S208, data is stored in the recording information section associated with the image data. This recording information part is a memory area secured in the RAM 70 every time a photographing operation is executed, and is prepared for each photographed image data. FIG. 4 shows the format of the recording information part. The recording information unit 200 includes an SD card storage address 201, a start address 202, a data size 203, and a checked flag 204. The SD card storage address 201 stores the value of the recording start address in the flash memory 92 when the image data recorded in the RAM 70 is recorded in the flash memory 92 of the SD card 90. The start address 202 stores the value of the start address of image data in the RAM 70. The data size 203 stores the data length of the image data. The checked flag 204 is a flag indicating whether or not the consistency between the image data recorded in the RAM 70 and the image data recorded in the flash memory 92 has been checked. When the value of this flag is “0”, it indicates that the image data is not matched as a result of the check not being performed or checked, and when it is “1”, the result of the check indicates that the image data is matched. . The image data consistency check process will be described later.
[0022]
As shown in FIG. 3, the storage of the value in the SD card storage address 201 is checked in step S202, the storage of the value in the start address 202 is in step S204, and the storage of the value in the data size 203 is checked in step S206. The value is stored in the flag 204 in step S208. At the time when the RAM writing subroutine is executed, the image data has not been written in the flash memory 92 of the SD card 90, and the above-described data consistency check has not yet been executed. Accordingly, in step S208, “0” is set in the checked flag 204.
[0023]
When the RAM writing subroutine in step S108 is completed, the process proceeds to step S110 in FIG. In step S <b> 110, the SD card writing process is executed, and the same image data as the image data written in the RAM 70 is written in the SD card 90.
[0024]
FIG. 5 is a flowchart showing a processing procedure of an SD writing subroutine executed in the SD writing processing, and FIG. 6 is a concept showing a part of the internal configuration of the RAM 70 of the digital camera 1 and the flash memory 92 of the SD card 90. FIG. FIG. 6 shows a state in which the image data P1 to P3 are written in the RAM 70 and the flash memory 92. The area of the image data is indicated by a rectangle, and the upper left corner is the position of the write start address. For example, in the RAM 70, the upper left corner of the image data P1 is indicated by an arrow extending from the start address of the recording information portion R1 associated with the image data P1, and the flash is indicated by an arrow extending from the SD card storage address of the recording information portion R1. The upper left corner of the image data P1 in the memory 92 is indicated. The same applies to the image data P2 and P3.
[0025]
Here, the writing to the SD card 90 will be described with reference to FIGS. 5 and 6 taking the image data P3 as an example. In step S300, the write command and the SD card storage address of the recording information section R3 associated with the image data P3 in the RAM 70 are transmitted from the microcomputer 10 to the controller 91 (see FIG. 1) of the SD card 90. Next, in step S302, it is checked whether a response from the controller 91 to the write command transmitted in step S300 has been received. This step is repeatedly executed until response reception is confirmed. The write command and the response include a CRC bit for CRC check. In this embodiment, the CRC bit is dummy data because communication is performed with the CRC function turned off.
[0026]
If the response reception is confirmed, the process proceeds to step S304. In step S304, it is checked whether the content of the response indicates that the reception by the controller 91 has ended abnormally. If the abnormal end is indicated, the routine ends.
[0027]
If the response does not indicate abnormal termination, the process proceeds to step S306. In step S306, it is checked whether all data (blocks) of the image data P3 have been transmitted. If it is confirmed that untransmitted data (block) exists, the process proceeds to step S308, and data transmission processing is performed together with CRC of dummy data. Next, the process proceeds to step S310. In step S310, a process for receiving a response from the controller 91 with respect to the data transmission performed in step S308 is performed. The CRC included in the response is also dummy data. When the SD card 90 is busy, a busy signal is received, and the wait state is maintained until the busy state is canceled. When the data reception normal end response or the busy state release response is received, the process returns to step S306, and the subsequent processing is repeated.
[0028]
If it is confirmed in step S306 that all the blocks of the image data P3 have been transmitted, this subroutine ends, the process returns to step S110 in FIG. 2, then returns to step S100, and the subsequent processing is repeated.
[0029]
If it is confirmed in step S102 of FIG. 2 that the shooting mode is not set, the process proceeds to step S112. If it is confirmed in step S104 that the release button has not been fully pressed, the process proceeds to step S112. In step S112, various processes corresponding to key inputs other than full release button pressing, that is, processes corresponding to the states of the switches other than the release switch 30 are executed. If the process corresponding to key input is performed, it will return to step S100 and the subsequent processes will be repeated.
[0030]
In step S100 of FIG. 2, when the key input is not confirmed and the microcomputer 10 is monitoring the key input and waiting for the next operation instruction, that is, when the digital camera 1 is in the standby state, step Proceed to S114. In the present embodiment, when the digital camera 1 is in a standby state, a comparison process is executed in step S114.
[0031]
FIG. 7 is a flowchart showing a processing procedure of a comparison subroutine executed in the comparison processing. During execution of this subroutine, interrupt processing for key input is permitted, and if there is any key input, processing corresponding to the key input is preferentially processed. However, in other cases, as long as image data having a valid recording information portion exists in the RAM 70, the process is repeatedly executed for each image data. In step S400, it is determined whether there is image data to be compared. In this determination processing, two points are checked, in the above-described recording information portion associated with each image data, whether there is no valid recording information portion and there is no uncompared image data.
[0032]
Whether or not the data in the recording information section is valid is determined by checking the value of the SD card storage address. That is, when the value of the SD card storage address is not an address value, for example, when the hexadecimal code “FFFFFFFF” is stored, it is determined that the data in the recording information portion is invalid. Note that the initial value of the SD card storage address immediately after the generation of the recording information portion is “FFFFFFFF”, and the address on the SD card for storing image data by a file management process (not shown) of the SD card that is executed separately. Is updated at a determined stage, and the recorded information portion becomes valid. The determination of whether or not the image data has been compared will be described later.
[0033]
Further, the microcomputer 10 knows the number of image data associated with the effective recording information part (in the example of FIG. 6, three, P1, P2, and P3), and the effective recording information part is associated. If it is confirmed that there is no image data or all the image data has been compared, this routine ends.
[0034]
If it is confirmed in step S400 that there is image data to be processed, the process proceeds to step S402. In step S402, one of the image data to be processed is selected, and it is checked whether or not the recording information portion is valid. Whether or not it is valid is determined based on the value of the SD card storage address as described above.
[0035]
If it is confirmed that the recording information part is valid, the process proceeds to step S404. In step S404, the recording information portion corresponding to the selected image data is read and stored in the work buffer. Next, the process proceeds to step S406, and the value of the checked flag is checked. If the value of the checked flag is “0” and the comparison processing of the image data has not been executed yet, or if it is confirmed that the image data does not match the image data of the SD card 90, the process proceeds to step S408. . In step 408, an SD card reading process is executed.
[0036]
FIG. 8 is a flowchart showing a processing procedure of an SD card reading subroutine executed in the SD card reading processing. In step S500, the read command and the SD card data storage address of the recording information portion stored in the work buffer are transmitted from the microcomputer 10 to the controller 91 (see FIG. 1) of the SD card 90. Next, in step S502, it is checked whether a response from the controller 91 to the read command transmitted in step S500 has been received. This step is repeatedly executed until response reception is confirmed. The point that the CRC included in the read command and the response from the read command is dummy data is similar to the above-described transmission / reception of the write command.
[0037]
If response reception is confirmed, the process proceeds to step S504. In step S504, it is checked whether the content of the response indicates that the reception by the controller 91 has ended abnormally. If the abnormal end is indicated, the routine ends.
[0038]
If the response does not indicate abnormal termination, the process proceeds to step S506. In step S506, it is checked whether all the image data has been received. If it is confirmed that unreceived data exists, the process proceeds to step S508, where data reception processing including CRC of dummy data is performed, and the received data is stored in the work buffer. Thereafter, the process returns to step S506, and the subsequent processing is repeated. That is, step S508 is repeatedly executed until it is confirmed that all the image data has been received. If it is confirmed in step S506 that all the image data has been received, this routine ends and the process returns to step S408 in FIG.
[0039]
When the SD card reading process in step S408 ends, the process proceeds to step S410. In step S410, the image data in the RAM 70 and the image data read from the flash memory 92 of the SD card 90 and stored in the work buffer are compared. The storage location of the image data in the RAM 70 is confirmed by referring to the start address stored in the work buffer.
[0040]
Next, the process proceeds to step S412, and it is checked whether there is data that does not match in the comparison process of step S410. If it is confirmed that there is data that does not match, that is, if it is detected that the data recorded in the SD card 90 is garbled, the process proceeds to step S414, and the above-mentioned SD card writing process is executed. The SD card writing subroutine is executed. That is, the image data in the RAM 70 is transmitted again to the SD card 90 and written. After execution of the SD card writing subroutine, the process proceeds to step S420, the image data to be processed next is searched, and the process returns to step S400.
[0041]
In step S412, if it is confirmed that there is no data mismatch (image data match), the process proceeds to step S416, and the recording information portion associated with the image data corresponding to the recording information portion stored in the work buffer. “1” is set in the checked flag. Thereby, it is shown that correct image data that completely matches the image data is written in the SD card 90. After execution of step S416, the process proceeds to step S420, the image data to be processed next is searched, and the process returns to step S400.
[0042]
When the digital camera 1 is in a standby state, the comparison subroutine is repeatedly executed until the checked flag “1” is set for all images. In the RAM 70, the writing area of the recording information section and the area of the image data in which the checked flag is “1” and the area of the image data are used as an area for writing the newly captured image data and the recording information section. The
[0043]
As described above, according to the present embodiment, the CRC bits included in the command and image data transmitted and received between the microcomputer 10 of the digital camera 1 and the controller 91 of the SD card 90 are dummy data. 10 and the controller 91 perform transmission / reception in the SPI mode with the CRC function turned off. Further, after the power is turned on to the digital camera 1, when there is no key input, that is, in a standby state, the image data stored in the RAM 70 and the image data recorded on the SD card 90 are compared. As a result, when a mismatch between the two is confirmed, a process of recording the image data in the RAM 70 on the SD card 90 is performed again. As a result, the image data is destroyed during transmission to the SD card 90 and is restored even if it is recorded as it is. Therefore, the image data can be transmitted at a higher speed and the reliability of the image data recorded on the SD card 90 can be maintained as compared with the case of communicating with the SD card 90 in the SPI mode with the CRC function turned on. be able to.
[0044]
【The invention's effect】
As described above, according to the present invention, an image taken with a digital camera can be recorded on an external recording medium at high speed, and the reliability of the image recorded on the external recording medium can be maintained. .
[Brief description of the drawings]
FIG. 1 is a block diagram of a digital camera and an SD card to which an embodiment according to the present invention is applied.
FIG. 2 is a flowchart showing a processing procedure of a main routine resident in the digital camera.
FIG. 3 is a flowchart showing a processing procedure of a subroutine for writing image data into a RAM of the digital camera.
FIG. 4 is a diagram illustrating a configuration of a recording information unit stored in association with image data in a RAM of a digital camera.
FIG. 5 is a flowchart showing a processing procedure of a subroutine for writing image data to an SD card.
FIG. 6 is a conceptual diagram showing a part of the internal configuration of the RAM of the digital camera and the flash memory of the SD card.
FIG. 7 is a flowchart showing a processing procedure for comparison processing between image data stored in a digital camera RAM and image data stored in a flash memory of an SD card.
FIG. 8 is a flowchart showing a processing procedure of a subroutine for reading image data in a flash memory of an SD card.
[Explanation of symbols]
1 Digital Camera 10 Microcomputer 20 Metering Switch 30 Release Switch 40 CCD
50 Shooting optical system 60 CDS / AD unit circuit 70 RAM
80 Operation button switch group 90 SD card 100 LCD
110 Mode switch

Claims (5)

Storage means provided inside the digital camera for storing captured image data;
Wherein transmitting the image data to the external recording medium provided outside the digital camera, the image data recording means for recording on the external recording medium without put out detection error of the image data transmitted,
When the consistency between the image data recorded on the storage means and the image data recorded on the external recording medium is not checked, the image data is read from the external recording medium and transmitted to the storage means, Comparing means for comparing the image data transmitted from the external recording medium with the image data stored in the storage means and checking the consistency thereof;
When the comparison means confirms that the image data in the storage means and the image data in the external recording medium do not match, the image data recording means is executed, and the image data in the storage means is Image data restoration means for overwriting the image data of the external recording medium;
A digital camera comprising: control means for executing processing of the comparison means and the image data restoration means when the digital camera after power-on is in a standby state.   Processing for recording the storage position of the image data in the storage means, the storage position of the image data in the external recording medium, the data size of the image data, the presence or absence of execution of processing of the control means, and the processing result The digital camera according to claim 1, wherein a flag is stored in the storage unit in association with the image data.   2. The digital camera according to claim 1, wherein when the digital camera is in the standby state, the control unit causes the comparison unit and the image data restoration unit to repeatedly execute processing.   3. The digital according to claim 2, wherein the comparison unit performs the comparison process based on a storage position of the image data in the storage unit and a storage position of the image data in the external recording medium. camera.   The digital camera according to claim 1, wherein the image data recording unit transmits dummy data together with the image data to the external recording medium.

Images