JP2009055560A - Mobile device, and method for recording imaged image data - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a mobile device capable of not only suppressing the current consumption of a rechargeable battery but also reducing the storage capacity that recorded imaged image data occupies in a recording medium. <P>SOLUTION: The mobile device is provided with: first encoding means; and second encoding means that, in comparison with the first encoding means, compresses data into a smaller amount of data consuming a larger amount of current to obtain an image of the same quality as the first encoding means does. At least when the remaining capacity of the battery is less than a predetermined value, imaged image data is compression-encoded by the first encoding means to be recorded in the recording medium by a recording means. When the battery is determined to be being charged, the imaged image data that has been compression-encoded by the first encoding means and recoded is re-encoded by the second encoding means to be re-recorded in the recording medium, and meanwhile the imaged image data that has been compression-encoded by the first encoding means and recoded is deleted from the recording medium. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a mobile device such as a mobile phone terminal with an imaging function and a method for recording captured image data in the mobile device.

  Recently, as mobile devices such as mobile phone terminals, not only a still image but also a moving image capturing function has appeared. In this type of portable device, captured image data is compressed and encoded by a predetermined compression encoding method so that as much captured image information as possible can be recorded on a recording medium having a finite storage capacity. To do.

  A conventional portable device uses a single type of compression encoding means, and when priority is given to the image quality of a captured image, recording is performed with a low compression rate and a high recording bit rate (high image quality mode). When attempting to record a captured image, recording (long-time mode) is performed by increasing the compression rate and decreasing the recording bit rate.

  For example, Patent Document 1 (Japanese Patent Laid-Open No. 2005-260838) discloses a technique in which a high-quality mode and a long-time mode can be switched by user operation during imaging and recording.

The above-mentioned patent documents are as follows.
JP 2005-260838 A

  In the case of the above-described conventional portable device, the compression encoding means uses one type and changes the compression ratio to switch between the high image quality mode and the long time mode. It is determined only by the compression ratio. Therefore, when recording so as to obtain an image of the same quality as a compression encoding means, a recording medium having a high compression rate and a small amount of data after compression is used. Can be reduced.

  However, when recording so that an image of the same quality can be obtained, a compression encoding means with a high compression rate and a small amount of data after compression generally requires a large amount of calculation for encoding. A large amount of current is required, and the current consumption of the rechargeable battery increases. For this reason, for example, in a mobile phone terminal with an imaging function, the battery consumption increases when the imaging function is used, and the telephone function is used when the standby time is shortened or telephone communication is attempted. There is a problem that it often causes situations that make it impossible.

  In view of the above points, the present invention provides a portable device capable of suppressing the consumption of a rechargeable battery as much as possible and reducing the recording capacity of recorded captured image data in a recording medium as much as possible. With the goal.

In order to solve the above problems, a portable device according to the present invention
Rechargeable batteries,
Imaging means;
First encoding means for compressing and encoding captured image data from the imaging means;
When the captured image data from the imaging unit is compression-encoded and an image having the same quality as the first encoding unit is obtained, the amount of data after compression is small, but the current consumption is the first encoding. More second encoding means than if using means;
Recording means for recording captured image data compressed and encoded by the first encoding means or the second encoding means on a recording medium;
At least when the remaining amount of the battery is less than a predetermined value, the captured image data from the imaging unit is compressed and encoded by the first encoding unit and recorded on the recording medium by the recording unit. Recording control means for controlling;
When the battery is being charged, the captured image data recorded by being compressed and encoded by the first encoding means is read from the recording medium and decoded, and the decoded captured image data is read by the second encoding means. Re-recording means for re-encoding and re-recording on the recording medium, and erasing the captured image data recorded after being compressed and encoded by the first encoding means from the recording medium;
It is characterized by providing.

  According to the portable device according to the present invention having the above-described configuration, when the remaining amount of the battery is less than the predetermined value by the recording control unit, the captured image data from the imaging unit is compressed and encoded by the first encoding unit. Then, it is recorded on the recording medium by the recording means. Therefore, the current consumption of the battery can be suppressed less than when the captured image data is recorded by compression encoding with the second encoding means.

  Then, when the battery is being charged, there is no concern about the remaining amount of the battery. Therefore, the captured image data that has been compressed and recorded by the first encoding means is read from the recording medium and decoded, and the decoding is performed. The captured image data that has been recorded is re-encoded by the second encoding means and re-recorded on the recording medium, and the captured image data that has been compressed and encoded by the first encoding means is erased from the recording medium.

  Since the amount of data after being encoded by the second encoding means is smaller than the amount of data after being encoded by the first encoder means, this re-recording increases the remaining capacity of the recording medium.

  According to the present invention, the consumption of the rechargeable battery can be suppressed as much as possible, and the used recording capacity of the recorded captured image data in the recording medium can be reduced.

  Hereinafter, an embodiment of a mobile device according to the present invention will be described with reference to the drawings, taking as an example the case where the mobile device is a mobile phone terminal.

[Hardware Configuration Example of Mobile Phone Terminal 1 of Embodiment]
FIG. 1 is a block diagram illustrating a hardware configuration example of the mobile phone terminal 1 of this embodiment. That is, in the mobile phone terminal 1 of this embodiment, the control unit 11, the communication circuit 12, the display unit 13, the operation unit 14, and the memory 15 are connected to the system bus including the control bus 101 and the data bus 102. The speaker 16, the microphone 17, the imaging control unit 18, and the charging control unit 19 are connected.

  The control unit 11 is constituted by a microcomputer, and the microcomputer stores software programs for controlling various processes of the mobile phone terminal 1 of this embodiment. Various control processes are executed according to the software program.

  In this embodiment, the software program included in the control unit 11 includes two types of encoding applications that perform data compression encoding on captured moving image data. In this example, one is an MPEG4 encoder 111 that performs data compression coding of the MPEG (Moving Picture Experts Group) 4 standard, and the other is H.264. H.264 (AVC) standard data compression encoding. H.264 encoder 112.

  When the MPEG4 encoder 111 is played back, When a moving image is compression-encoded and encoded so as to ensure the same level of image quality and resolution as when the H.264 encoder 112 is used, H.264 is used. The amount of recorded data is larger than that of the H.264 encoder 112, but the battery current consumption is small. On the other hand, H. When the H.264 encoder 112 compresses and encodes the moving image so that the quality such as the image quality and the resolution can be secured at the same level as when the MPEG4 encoder 111 is used, The amount can be about ½ that of the MPEG4 encoder 111, but the battery current consumption increases.

  The communication circuit 12 is a wireless communication unit for mobile phone communication for performing telephone communication and other information communication through a base station and a mobile phone network, and transmits and receives communication data through an antenna 12AT.

  The display unit 13 includes a display element such as a liquid crystal display, and displays various display screens and displays captured moving images on a monitor while the display element is controlled by the control unit 11. It has a function.

  The operation unit 14 includes a numeric keypad and other keys. Since the cellular phone terminal 1 of this embodiment has a moving image capturing function, it also includes a key for switching to the moving image capturing mode, a key for controlling start and stop of moving image recording, and the like. The control unit 11 is configured to detect which key is operated through the operation unit 14 and execute a control processing operation corresponding to the operated key.

  In this embodiment, the memory 15 constitutes an example of a recording medium for captured image data. The memory 15 may be a memory built in the mobile phone terminal 1 made of a semiconductor memory such as a flash memory, or a removable memory that can be inserted into and removed from the mobile phone terminal 1 such as a card-type memory. Also good.

  In this embodiment, the control unit 11 always grasps and manages the free capacity of the memory 15.

  The memory 15 stores phonebook data, e-mail addresses, URL (Uniform Resource Locator), and other data stored in the mobile phone terminal 1 as well as stored data associated with the functions of the mobile phone terminal 1. It may be.

  The speaker 16 performs a function of reproducing a received voice in telephone communication, and is also used for acoustic reproduction of recorded voice data.

  The microphone 17 is used to pick up the transmitted voice of telephone communication, and is also used to pick up the peripheral voice that records the image data together when capturing a moving image.

  A camera 20 as an imaging unit is connected to the imaging control unit 18. When the user performs a key operation for selecting a camera mode (moving image captured image recording mode) on the mobile phone terminal 1 on the operation unit 14, the control unit 11 controls the image capturing control unit 18 to control the camera 20. Control is performed so that moving image captured image data from the image data is taken into the data bus 102. The captured moving image captured image data is converted into a display image signal (an application program for this conversion is also provided in the control unit 11), and the captured moving image is displayed on the display unit 13, which is a so-called electronic viewfinder. Function is realized.

  When the user performs a key operation to start moving image recording, the moving image captured data from the camera 20 captured through the imaging control unit 18 is encoded by the encoder 111 of the control unit 11 as described in detail later. Or, after 112 is used for compression encoding, it is recorded in the memory 15 and moving image recording is executed. When the user performs a key operation to stop moving image recording and recording, the moving image recording and recording is stopped.

  The charging control unit 19 is connected to the charging terminal 22 while being connected to the rechargeable battery 21. The charging terminal 22 is connected to a terminal of a charging stand connected to a power plug connected to a commercial AC power outlet. Alternatively, the charging terminal includes a connector jack into which a connector plug connected to a commercial AC power outlet is inserted.

  When the charging terminal 22 is connected to the terminal of the charging stand connected to the commercial AC power outlet, or the connector plug connected to the commercial AC power outlet is inserted into the connector jack constituting the charging terminal. Then, the charging control unit 19 detects the connection of the charging terminal 22 to the charging stand or the insertion of the connector plug into the connector jack, and starts charging the rechargeable battery 21, and also starts a charging start signal. Is sent to the control unit 11 through the data bus 102 to notify the start of charging.

  The charge control unit 19 also has a function of detecting the remaining battery level of the rechargeable battery 21 and notifying the control unit 11 of the detected remaining battery level via the data bus 102.

  When detecting the connection to the charging base or the insertion of the connector plug into the connector jack, the control unit 11 encodes and records the imaged image data stored in the memory 15 by the MPEG4 encoder 111 as will be described later. The captured image data is encoded with the encoding method H.264. Change to the H.264 encoder 112 and perform necessary rewriting and re-recording.

[Operation of moving image recording of mobile phone terminal 1]
The cellular phone terminal 1 of this embodiment includes a high image quality mode and a long time mode as the imaging recording mode of the moving image imaging recording, and the operation unit 14 determines which imaging recording mode the user sets in advance. It can be set using.

  The high image quality mode is a mode in which the data compression rate is low and recording is performed so that the high image quality can be maintained when reproduced. The long-time mode is a mode that enables recording of moving image captured image data for a long time in the memory 15 by increasing the data compression rate and reducing the amount of recording data.

  In this embodiment, the MPEG4 encoder 111 and the H.264 are both in the high image quality mode and the long time mode. Any of H.264 encoding 112 is used. Therefore, the MPEG4 encoder 111 and the H.264 Both the H.264 encoding 112 and the H.264 encode 112 have a compression rate in the high image quality mode and a compression rate in the long time mode.

  In the high image quality mode, it is ensured that moving image captured image data is recorded with the same quality regardless of which encoder is used, and the compression rate CM1 of the high image quality mode in the MPEG4 encoder 111 is H., et al. Unlike the compression ratio CM2 in the high-quality mode in the H.264 encoder 112, CM1 <CM2 is satisfied. The H.264 encoder 112 has a higher compression rate.

  Also, in any long-time mode, it is ensured that moving image captured image data is recorded with the same quality regardless of which encoder is used. H., et al. Unlike the long-time mode compression rate CM4 in the H.264 encoder 112, CM3 <CM4 (CM1 <CM2 <CM3 <CM4) is set. The H.264 encoder 112 has a higher compression rate.

  In both the image-recording recording modes of the high image quality mode and the long-time mode, the control unit 11 determines that the remaining battery level of the rechargeable battery 21 is greater than a predetermined threshold and the remaining battery level is sufficient. When determined, the encoder The H.264 encoder 112 is used to reduce the amount of recording data and reduce the use capacity of the memory 15. However, in the long-time mode, the control unit 11 preferentially uses the MPEG4 encoder 111 in order to reduce the current consumption of the battery as much as possible when the free space of the memory is larger than a predetermined threshold free space. To control.

  Further, the control unit 11 uses the MPEG4 encoder 111 in order to reduce current consumption as much as possible when the remaining battery level of the rechargeable battery 21 becomes smaller than a predetermined threshold and the remaining battery level is reduced. To control.

  The moving image recording / recording operation in this embodiment will be described with reference to the flowcharts of FIGS. Each step of the flowcharts of FIGS. 2 and 3 is shown to be executed by the control unit 11.

  The flowcharts of FIGS. 2 and 3 start from the start of recording when the user selects the camera mode and performs a key operation for starting moving image recording.

  First, the control unit 11 determines what the set imaging recording mode is (step S101). When it is determined in this step S101 that the high image quality mode is set as the imaging recording mode, the control unit 11 checks the remaining battery level of the rechargeable battery 21 (step S102), and the remaining battery level is determined in advance. It is determined whether the remaining battery level is greater than the threshold value (step S103).

  When it is determined in this step S103 that the remaining battery level is sufficient, the control unit 11 uses H.264 as an encoder. The H.264 encoder 112 is selected, and the compression rate is set to a low compression rate CM2 for the high image quality mode, and writing (recording) of the moving image captured image data to the memory 15 is executed (step S104). At this time, as additional information, the compression encoding method is H.264. H.264 and the high image quality mode are recorded in the memory 15 in correspondence with the written moving image captured image data. Note that the moving image captured image data is recorded as one file from the start of recording to the stop of recording.

  Then, the control unit 11 determines whether or not the user has performed a key operation for moving image capturing / recording stop (step S105), and when determining that the key operation for moving image capturing / recording stop has not been performed, the control unit 11 returns to step S104. H. The recording of the moving image captured image data encoded by the H.264 encoder 112 in the memory 15 is continued.

  If it is determined in step S105 that the moving image capturing / recording stop key operation has been performed, the control unit 11 stops writing the captured moving image data to the memory 15 and performs an end processing of the imaging / recording mode (step S105). S106), this processing routine is terminated.

  If it is determined in step S103 that the remaining battery level is not sufficient, the control unit 11 selects the MPEG4 encoder 112 as an encoder, and sets the compression rate as a low compression rate CM1 for the high image quality mode. Writing (recording) of moving image captured image data to the memory 15 is executed (step S107). At this time, as additional information, the fact that the compression encoding encoding method is MPEG4 and the high image quality mode are recorded in the memory 15 in association with the written moving image captured image data.

  Then, the control unit 11 determines whether or not the user has performed a key operation for moving image capturing / recording stop (step S108). When determining that the key operation for moving image capturing / recording stop has not been performed, the control unit 11 returns to step S107. Thus, the recording of the moving image captured image data encoded by the MPEG4 encoder 111 in the memory 15 is continued in the high image quality mode.

  When it is determined in step S108 that the key operation for moving image capturing / recording stop has been performed, the control unit 11 stops the writing of the moving image captured image data to the memory 15 and performs the end processing of the imaging / recording mode (step S108). S106), this processing routine is terminated.

  When it is determined in step S101 that the long-time mode is set as the imaging recording mode, the control unit 11 confirms the remaining battery level of the rechargeable battery 21 (step S111 in FIG. 3), and the remaining battery level. Is larger than a predetermined threshold value, and it is determined whether or not the remaining battery level is sufficient (step S112).

  When it is determined in this step S112 that the remaining battery level is sufficient, the control unit 11 checks the free space (memory remaining amount) of the memory 15 (step S113), and the confirmed free space is determined in advance. It is determined whether or not it is less than the threshold free space (step S114).

  When it is determined in step S114 that the free space in the memory 15 is smaller than the predetermined threshold free space, the control unit 11 uses H.264 as an encoder. The H.264 encoder 112 is selected, and the compression rate is set to the compression rate CM4 for the long-time mode, and writing (recording) of the moving image captured image data to the memory 15 is executed (step S115). At this time, as additional information, the compression encoding method is H.264. H.264 and the long-time mode are recorded in the memory 15 in correspondence with the written moving image captured image data.

  Then, the control unit 11 determines whether or not the user has performed a key operation for stopping moving image recording / recording (step S116). When determining that the key operation for stopping moving image recording / recording has not been performed, the control unit 11 returns to step S115. H. The long-time mode recording of the moving image captured image data encoded by the H.264 encoder 112 to the memory 15 is continued.

  When it is determined in step S116 that the key operation for moving image capturing / recording stop has been performed, the control unit 11 stops the writing of the moving image captured image data to the memory 15 and performs the end processing of the imaging / recording mode (step S116). S117), this processing routine is terminated.

  If it is determined in step S112 that the remaining battery level is not sufficient, or if it is determined in step S114 that the remaining memory capacity of the memory 15 is larger than the threshold free capacity, the control unit 11 As a result, the MPEG4 encoder 111 is selected, and the compression rate is set to the high compression rate CM3 for the long-time mode, and writing (recording) of the moving image captured image data to the memory 15 is executed (step S118). At this time, as additional information, the fact that the compression encoding method is MPEG4 and the long-time mode are recorded in the memory 15 in association with the written moving image captured image data.

  Then, the control unit 11 determines whether or not the user has performed a key operation for moving image capturing / recording stop (step S119). When determining that the key operation for moving image capturing / recording stop has not been performed, the control unit 11 returns to step S118. Thus, the long-time mode recording of the moving image captured image data encoded by the MPEG4 encoder 111 to the memory 15 is continued.

  When it is determined in step S119 that the moving image capturing / recording stop key operation has been performed, the control unit 11 stops writing the captured moving image data to the memory 15 and performs the end processing of the imaging / recording mode (step S119). S117), this processing routine is terminated.

  As described above, in this embodiment, two types of image compression encoding encoders are used to record moving images in the high image quality mode and the long time mode, the remaining battery level of the rechargeable battery 21, and the memory 15. This can be realized in a state where the remaining battery capacity of the rechargeable battery 21 and the free capacity of the memory 15 are efficiently used while taking the free capacity into consideration.

[Encoder conversion re-recording of moving image data]
Furthermore, in this embodiment, the moving image captured image data encoded by the MPEG4 encoder 111 and recorded in the memory 15 during charging, in which the current consumption of the battery need not be taken into consideration, is stored in the H.264 format. By converting the data encoded by the H.264 encoder 112 and re-recording, the free space of the memory 15 can be secured.

  The re-recording process during charging in this embodiment will be described with reference to the flowchart of FIG. The processing of each step shown in the flowchart of FIG. 4 is also executed by the control unit 11.

  First, the control unit 11 monitors the charging start signal from the charging control unit 19 to determine whether or not charging of the rechargeable battery 21 has started (step S121). When determining that charging has not started, The control unit 11 performs other normal processing (step S122).

  When it is determined in step S121 that charging of the rechargeable battery 21 is started, the control unit 11 determines whether or not there is a moving image captured image data file in the memory 15 (step S123). When it is determined that the data does not exist, this processing routine is terminated.

  When it is determined in step S123 that the moving image captured image file exists, the control unit 11 analyzes the additional information additionally recorded in the moving image captured image file (step S124), and the compression encoding method is MPEG4. It is determined whether or not a certain moving image captured image file exists, whether or not conversion re-recording is necessary (step S125), and there exists a moving image captured image file whose compression encoding encoding method is MPEG4. If it is determined not to do so, this processing routine is terminated.

  When it is determined in step S125 that there is a moving image captured image file whose compression encoding encoding method is MPEG4, the control unit 11 identifies from the additional information whether the imaging recording mode is the high image quality mode or the long time mode. (Step S126).

  Then, the control unit 11 decodes the moving image captured image file encoded in MPEG4 (step S127), and converts the decoded moving image captured image data into H.264. Re-encoding is performed by the H.264 encoder 112 (step S128). At the time of this re-encoding, the compression rate corresponding to the image recording mode of the high image quality mode and the long time mode identified in step S126 is H.264. H.264 encoder 112 is used. Then, the control unit 11 re-records the re-encoded moving image captured image data file in the memory 15 together with additional information for identifying the original imaging recording mode (step S129).

  Then, the control unit 11 deletes the MPEG4 moving image captured image file that has been converted and re-recorded from the memory 15 (step S130).

  Next, the control unit 11 determines whether or not there is a moving image captured image file that has not been checked (step S131). When determining that there is an unchecked moving image captured image file, the control unit 11 returns to step S123. Then, the additional information of the moving image captured image file is analyzed, and the processes after step S123 described above are repeated. When it is determined in step S131 that there is no moving image captured image file not checked, the control unit 11 ends this processing routine.

  As described above, according to this embodiment, while using a rechargeable battery, moving image captured image data encoded by the MPEG4 encoder 111 can be converted into H.264 format during charging so that current consumption can be reduced. Since it can be re-recorded in the moving image captured image data re-encoded by the H.264 encoder 112, an encoder capable of reducing the amount of recording data can be used while taking into account current consumption. Moreover, in this embodiment, the quality of the moving image captured image can be maintained even after conversion re-recording.

[Other Embodiments and Modifications]
The above embodiment is a case where the portable device of the present invention is applied to a mobile phone terminal. However, the portable device of the present invention is any portable device that has a camera function and uses a rechargeable battery as a power source. Even if it is a thing, it is applicable.

  In the above description, the captured image data has been described as moving image data. However, the present invention can also be applied to still image data.

  The encoders are MPEG4 and H.264. The relationship between the amount of recorded data after compression and the current consumption is not limited to H.264. Any encoding method may be used as long as the relationship with H.264 is the same.

  In the above-described embodiment, the encoder is mounted on the portable device as a software program application, but either or both may be mounted as hardware.

It is a block diagram which shows the structural example of embodiment of the portable apparatus by this invention. It is a part of flowchart for demonstrating the example of an imaging recording operation in embodiment of the portable apparatus by this invention. It is a part of flowchart for demonstrating the example of an imaging recording operation in embodiment of the portable apparatus by this invention. It is a flowchart for demonstrating the operation example of the principal part in embodiment of the portable apparatus by this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 11 ... Control part, 15 ... Memory (recording medium), 19 ... Charge control part, 20 ... Camera, 21 ... Rechargeable battery, 22 ... Charge terminal, 111 ... MPEG4 encoder, 112 ... H. H.264 encoder

Claims (6)

Rechargeable batteries,
Imaging means;
First encoding means for compressing and encoding captured image data from the imaging means;
When the captured image data from the imaging unit is compression-encoded and an image having the same quality as the first encoding unit is obtained, the amount of data after compression is small, but the current consumption is the first encoding. More second encoding means than if using means;
Recording means for recording captured image data compressed and encoded by the first encoding means or the second encoding means on a recording medium;
At least when the remaining amount of the battery is less than a predetermined value, the captured image data from the imaging unit is compressed and encoded by the first encoding unit and recorded on the recording medium by the recording unit. Recording control means for controlling;
When the battery is being charged, the captured image data recorded by being compressed and encoded by the first encoding means is read out from the recording medium and decoded, and the decoded captured image data is converted into the second encoding. Re-encoding means, re-recording on the recording medium, and re-recording means for erasing the captured image data recorded after being compressed and encoded by the first encoding means from the recording medium;
A portable device comprising: The mobile device according to claim 1,
A high image quality mode for recording captured image data from the imaging means on the recording medium with a higher image quality than that of other imaging modes,
In the high image quality mode, the recording means is
When the remaining amount of the battery is larger than a predetermined first value, the captured image data compression-encoded at the first compression rate in the second encoding means is recorded on a recording medium,
When the remaining amount of the battery is less than the predetermined first value, additional information indicating that the captured image data compression-encoded at the second compression rate in the first encoding unit is in a high image quality mode is provided. Add and record,
The re-recording unit recognizes the high-quality mode based on the additional information, re-encodes the decoded captured image data at the first compression rate by the second encoding unit, and re-records on the recording medium. A portable device characterized by that. The portable device according to claim 1 or 2,
A long-time mode for recording captured image data from the imaging unit on the recording medium for a longer time than other imaging modes,
In the long time mode, the recording means is
When the remaining amount of the battery is larger than a predetermined first value and the free capacity of the recording medium is larger than a predetermined second value, the second encoding means compresses at a third compression rate. Record the encoded captured image data on a recording medium,
When the remaining amount of the battery is smaller than the predetermined first value, or when the free capacity of the recording medium is smaller than the second value, the first encoding means uses the fourth compression rate. Record the compression-encoded captured image data with additional information indicating the long-time mode,
The re-recording unit recognizes the long-time mode based on the additional information, re-encodes the decoded captured image data at the third compression rate by the second encoding unit, and re-records the data on the recording medium. A portable device characterized by that.   The mobile device according to any one of claims 1 to 3, wherein the mobile device is a mobile phone terminal. In the portable apparatus in any one of Claims 1-4,
A portable device characterized in that at least the second encoding means is a software application. Rechargeable batteries,
Imaging means;
First encoding means for compressing and encoding captured image data from the imaging means;
When the captured image data from the imaging unit is compression-encoded and an image having the same quality as the first encoding unit is obtained, the amount of data after compression is small, but the current consumption is the first encoding. More second encoding means than if using means;
Recording means for recording captured image data compressed and encoded by the first encoding means or the second encoding means on a recording medium;
A method for recording image data in a portable device comprising:
At least when the remaining amount of the battery is less than a predetermined value, the captured image data from the imaging unit is compressed and encoded by the first encoding unit and recorded on the recording medium by the recording unit. Recording control process to control;
A determination step of determining whether or not the battery is being charged;
When it is determined that the battery is being charged in the determining step, the captured image data compressed and encoded by the first encoding unit and recorded by the recording unit is read from the recording medium and decoded;
The decoded captured image data is re-encoded by the second encoding unit and re-recorded on the recording medium, and the captured image data recorded by being compressed and encoded by the first encoding unit is recorded on the recording medium. A re-recording process to erase from the medium;
A method of recording captured image data, comprising:

Images