JP2016201781A - Image recording apparatus, image recording method, and imaging apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable image recording in which the capacity of a storage medium is more efficiently utilized.SOLUTION: An image recording apparatus includes: image acquisition means that obtains image data; image compression means that generates recording data including compressed image data which is obtained by compressing the image data; recording means that records the recording data in a storage medium; free space check means that checks the free space of the storage medium; and recording propriety determination means that compares the data amount of the generated recording data and the free space, and determines the propriety of recording the recording data in the recording medium.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an image recording apparatus, an image recording method, and an imaging apparatus including the image recording apparatus.

  The digital camera includes a drive device for a portable storage medium such as a memory card for recording captured images (moving image data or still image data). When recording a relatively large amount of data such as image data on a storage medium having a relatively small storage capacity such as a portable storage medium, it is important to manage the free capacity of the storage medium.

  In Patent Literature 1, when recording a moving image is started, a predicted value of the recordable recording time (predictable recordable time) is calculated from the free capacity of the storage medium, and immediately before the recordable time exceeds the predictable recordable time. Describes a technique for effectively using the storage capacity of a storage medium by automatically stopping the recording of moving images.

Japanese Patent No. 3779941

  The amount of compressed and encoded image data varies greatly depending on the correlation of image information in the spatial domain (correlation between neighboring pixels) and the correlation in the time domain (correlation between frames). Therefore, in the technique described in Patent Document 1, the length of a video that can actually be recorded (actual recording time) is longer than the predicted recording time, and recording is stopped while leaving a free space. There was a problem.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to enable image recording using the capacity of a storage medium more effectively than in the prior art.

  An image recording apparatus according to an embodiment of the present invention includes an image acquisition unit that acquires image data, an image compression unit that generates recording data including compressed image data obtained by compressing the image data, and stores the recording data The recording means for recording on the medium, the free capacity confirmation means for confirming the free capacity of the storage medium, the data amount of the generated recording data and the free capacity are compared, and the recording data is recorded on the storage medium. Recording availability determination means for determining availability.

In the above image recording apparatus, a compression degree setting means for setting a compression degree that defines the degree of data compression, and a compression ratio calculation means for calculating a representative value of the compression ratio of the compressed image data generated after the start of the image recording apparatus A recordable image amount predicting unit that calculates a predicted value of the number of still images or the length of a moving image that can be recorded in the recording unit based on the free space, a display unit that displays the predicted value,
And when the compressed image data is not generated after starting the image recording apparatus, the recordable image amount predicting means calculates a predicted value based on the free space and the degree of compression, and after starting the image recording apparatus When compressed image data is generated, a predicted value may be calculated based on representative values of free space and compression rate.

  Further, in the above image recording apparatus, the compression ratio calculation means calculates a representative value of the compression ratio based on the compression ratio of a predetermined number of compressed image data generated immediately after the image recording apparatus is activated. Also good.

  In the above image recording apparatus, the compression ratio calculation means calculates a representative value of the compression ratio based on the compression ratio of the compressed image data generated within a predetermined time immediately after the image recording apparatus is started. It is good.

  The image recording apparatus further includes a temporary storage unit that temporarily stores recording data, and the recording availability determination unit compares the data amount of the recording data stored in the temporary storage unit with the free space. Then, it may be configured to determine whether or not recording data can be recorded in the recording unit.

  In the image recording apparatus, the recording data is moving image data generated from a plurality of compressed image data stored in the temporary storage unit, and the recording unit stores the recording data in a reproducible unit. A configuration for recording on a medium may be adopted.

  In the above image recording apparatus, the image data may be frame data constituting moving image data, and the recording data may be a packet constituting a file in which moving image data is stored.

  Further, in the above image recording apparatus, when the recording unit determines that the recording possibility determination unit determines that recording is not possible, it indicates that the recording data last recorded on the storage medium is the last data unit (packet). It is good also as composition which adds a tag.

  In addition, an imaging apparatus according to an embodiment of the present invention includes an imaging unit that captures an image of a subject and generates image data, and the above-described image recording apparatus.

  An image recording method according to an embodiment of the present invention includes an image acquisition step of acquiring image data, an image compression step of generating recording data including compressed image data obtained by compressing the image data, and a free space of a storage medium A free space confirmation step for confirming recording, a recording availability determination step for comparing the data amount of the generated recording data with the free space, and determining whether or not recording data can be recorded on the storage medium, and a recording availability determination A recording step of recording data for recording on a storage medium when it is determined that recording is possible in the step.

  According to an embodiment of the present invention, it is possible to record an image using the storage medium capacity more efficiently.

It is a block diagram which shows schematic structure of the imaging device which concerns on embodiment of this invention. It is a flowchart which shows the procedure of the moving image recording process which concerns on embodiment of this invention. It is a flowchart which shows the procedure of the process performed during recording of a moving image.

  Hereinafter, a photographing apparatus according to an embodiment of the present invention will be described with reference to the drawings. In the following, a digital single lens reflex camera will be described as an embodiment of the present invention. Note that the photographing apparatus is not limited to a digital single lens reflex camera, but includes, for example, a mirrorless single lens camera, a compact digital camera, a video camera, a camcorder, a tablet terminal, a PHS (Personal Handy phone System), a smartphone, a feature phone, a portable game machine, and the like. Alternatively, another type of apparatus having a photographing function, a system combining these apparatuses, or a system having functions equivalent to these apparatuses may be used.

[Configuration of the photographing apparatus 1]
FIG. 1 is a block diagram illustrating a schematic configuration of a photographing apparatus 1 according to the present embodiment. As illustrated in FIG. 1, the photographing apparatus 1 includes a system control unit 10, a ROM (Read Only Memory) 11, a RAM (Random-Access Memory) 12, an imaging unit 20, an optical control unit 31, a photographing lens 32, and a diaphragm 33. A shutter 34, an image processing unit 40, a memory card interface 61, a memory card 61a, a flash memory 62, a display device 71, a video output unit 72, a power supply unit 91, and an operation unit 92. Note that the photographing lens 32 is symbolically shown by one lens in FIG. 1, but actually includes a plurality of optical lenses, optical filters, and the like.

  The operation unit 92 includes various switches necessary for the user to operate the photographing apparatus 1, such as a power switch, a release switch, and a photographing mode switch. When the user operates the power switch, power is supplied from a power supply unit 91 including a battery to various circuits of the photographing apparatus 1 through a power supply line (not shown).

  The system control unit 10 is a functional unit that manages the operation of the entire photographing apparatus 1 and includes a processor such as a CPU (Central Processing Unit) and a DSP (Digital Signal Processor). After supplying power, the system control unit 10 accesses the ROM 11, reads out a control program, loads it into a work area (RAM 12 or the like), and executes the loaded control program, thereby controlling the entire photographing apparatus 1.

  When the release switch is operated, the system control unit 10 is measured by, for example, a photometric value calculated based on an image captured by the imaging unit 20 or an exposure meter (not shown) built in the imaging apparatus 1. The diaphragm 33 and the shutter 34 are driven and controlled via the optical control unit 31 so that appropriate exposure can be obtained based on the photometric values. More specifically, drive control of the aperture 33 and the shutter 34 is performed based on an AE function specified by the shooting mode switch, such as a program AE (Automatic Exposure), shutter priority AE, aperture priority AE, or the like. Further, the system control unit 10 performs AF (Autofocus) control together with AE control. An active method, a phase difference detection method, a contrast detection method, or the like is applied to the AF control. The AF mode includes a central single-point ranging mode using a single central ranging area, a multi-point ranging mode using a plurality of ranging areas, and the like. The system control unit 10 drives and controls the photographing lens 32 via the optical control unit 31 based on the result of the AF control, and adjusts the focus of the photographing lens 32. Since the configuration and control of this type of AE and AF are well known, detailed description thereof is omitted here.

  The imaging unit 20 includes a solid-state imaging device 21, a drive circuit 22 that generates a drive signal for the solid-state imaging device 21, and an AFE (Analog Front) that processes the analog imaging signal generated by the solid-state imaging device 21 to generate a digital imaging signal. -End) 23.

  The light flux from the subject passes through the photographic lens 32, the diaphragm 33, and the shutter 34 and forms an image on the light receiving surface of the solid-state imaging device 21. The solid-state imaging device 21 is a single-plate CMOS (Complementary Metal Oxide Semiconductor) color image sensor having a Bayer pixel arrangement. The solid-state imaging device 21 accumulates an optical image formed by each pixel on the light receiving surface as a charge corresponding to the amount of light, and generates analog imaging signals of R (Red), G (Green), and B (Blue). Output. The solid-state imaging device 21 is not limited to a CMOS image sensor, and may be replaced with a CCD (Charge Coupled Device) image sensor or other types of imaging devices. The solid-state image sensor 21 may also be one having a complementary color filter.

  The AFE 23 performs processing such as reset noise removal by CDS (Correlated Double Sampling), automatic gain control, and analog-digital conversion on the analog imaging signal output from the solid-state imaging device 21 to generate a digital imaging signal. Output.

  The image processing unit 40 performs signal processing such as clamping, defect correction, demosaicing, linear matrix, white balance, contour correction, gamma correction, Y / C separation, and color difference correction on the digital imaging signal output from the AFE 23. Thus, the luminance signal Y and the color difference signals Cb and Cr are generated.

  The image processing unit 40 includes a frame memory 41, a buffer memory 42, and a general-purpose memory 43. The image processing unit 40 stores the captured image data before compression in the frame memory 41 sequentially in units of frames. The image processing unit 40 sweeps the captured image data stored in the frame memory 41 at a predetermined timing, converts it into a video signal of a predetermined format, and outputs it to the display device 71 and the video output unit 72.

  The display device 71 is an image display device such as a liquid crystal display (LCD) or an organic EL display (OELD). The display device 71 displays the captured image of the subject on the display screen based on the video signal output from the image processing unit 40. The user can visually recognize a real-time through image (live view) captured in an appropriate exposure and in-focus state based on the AE control and AF control through the display screen of the display device 71 during shooting.

  The video output unit 72 is connected to an external display device or video equipment by wire or wirelessly, and outputs a video signal output from the image processing unit 40 to an external display device or the like.

  Further, the image processing unit 40 reads out the captured image data stored in the frame memory 41 and, for example, JPEG (Joint Photographic Experts Group) format or ITU-T (International Telecommunication Union Telecommunication Standardization Sector) recommendation H.264. The image data is compressed in a predetermined format such as H.264 (MPEG [Moving Picture Experts Group] -4 AVC). The captured image data after compression is a basic unit of data constituting a file (for example, in the case of moving image data in the H.264 format or the like, a unit such as a PES [Packetized Elementary Stream] packet or movie fragment), or JPEG In the case of still image data in the format, it is stored in the buffer memory 42 in units of files) or in units of a predetermined number of captured images (frames).

  A memory card 61 a is detachably inserted into the card slot of the memory card interface 61. The memory card interface 61 is an auxiliary storage device that writes and reads captured image data and the like to and from the memory card 61a inserted into the card slot.

  The image processing unit 40 accesses the memory card 61 a via the memory card interface 61 or directly to the flash memory 62, and stores the captured image data compressed and converted into a predetermined format in the memory card 61 a or the flash memory 62. . The format of the captured image data to be saved is JPEG format or H.264 format. The RAW format is not limited to the H.264 format, and may be, for example, a RAW format in which only minimum image processing (for example, correction processing such as clamping) is performed.

  When the user performs a reproduction operation of the captured image, the image processing unit 40 reads the captured image data designated by the operation from the memory card 61a or the flash memory 62, converts the data into a video signal of a predetermined format, and displays the display device 71. Output to. The display device 71 displays a captured image of the subject on the display screen based on the image signal input from the image processing unit 40.

[Movie recording process]
Next, the moving image recording process according to the embodiment of the present invention, which is executed in the photographing apparatus 1 described above, will be described.

  FIG. 2 is a flowchart showing the procedure of the moving image recording process. The moving image recording process is started when a request to start recording a moving image is received by a user operation on the operation unit 92 (specifically, a pressing operation of a recording button (not shown)).

[Remaining capacity confirmation processing S1]
In the moving image recording process, first, the free capacity (hereinafter “remaining capacity”) of the auxiliary storage device (memory card 61a or flash memory 62) set as the storage destination of moving image captured image data (hereinafter referred to as “moving image data”). ”) Is performed (remaining capacity confirmation process S1). Here, a case where the memory card 61a is set as a moving image data storage destination will be described as an example. In this case, the system control unit 10 inquires of the memory card interface 61 about the remaining capacity of the memory card 61a. Then, the memory card interface 61 accesses the memory card 61a, acquires information on the remaining capacity of the memory card 61a, and transfers the information on the remaining capacity to the system control unit 10.

  The system control unit 10 calculates a predicted value of the time that can be recorded in the memory card 61a from the remaining capacity (in the case of a still image, the number of images that can be stored in the memory card 61a), and displays it on the display device 71.

  In the present embodiment, the degree of image compression (hereinafter referred to as “compression degree”) is preset in three stages of “high”, “medium”, and “low” by a user operation on the operation unit 92. . In an image compression process S43, which will be described later, image compression (high-efficiency encoding) is performed using a quantization parameter set in association with the degree of compression. In the remaining capacity confirmation processing S1, a predicted value of the recordable time is calculated based on a standard compression rate (predicted compression rate) when an image is compressed with a quantization parameter corresponding to the set compression level.

[Remaining capacity determination S2]
Next, it is determined whether or not the remaining capacity of the memory card 61a confirmed in the remaining capacity confirmation processing S1 is equal to or larger than the minimum capacity suitable for moving image recording (hereinafter referred to as “moving image recording start permitted capacity”). A remaining capacity determination S2 is performed. The moving image recording start permission capacity is a reference value set in advance for determining whether or not to record moving image data. The movie recording start permission capacity is set based on the reference data amount of moving image data (captured image data) per frame, the reference data amount of a packet (described later) that is a basic unit of data constituting the moving image file, and the like. The Here, the reference data amount is a standard data amount of each data.

  When the remaining capacity of the memory card 61a acquired in the remaining capacity confirmation processing S1 is smaller than the moving image recording start permission capacity, it is determined that there is no remaining capacity (S2: NO), and moving image recording (recording) is executed. The moving image recording process ends. At this time, a process of notifying the user of a shortage of the remaining capacity of the memory card 61a is also performed.

[Movie recording start process S3]
If the remaining capacity of the memory card 61a is equal to or larger than the moving image recording start permission capacity, it is determined that there is remaining capacity (S2: YES), and moving image recording is started (S3). At this time, a recording start command is transmitted from the system control unit 10 to the image processing unit 40. Receiving the recording start command, the image processing unit 40 creates a moving image file in a predetermined format (for example, H.264 format) in the memory card 61a, and writes management information such as the file creation time to the moving image file.

[Movie recording process S4]
FIG. 3 is a flowchart showing the procedure of the process S4 performed during recording of a moving image.

[Image Import S41]
In the process S4, first, captured image data of a frame constituting the moving image is acquired (S41). Specifically, the solid-state imaging device 21 captures an optical image of a subject based on a drive signal periodically output from the drive circuit 22 of the imaging unit 20, and a digital imaging signal output from the AFE 23 is an image processing unit 40. The captured image of the frame is captured.

[Image signal processing S42]
Next, various image processing such as demosaicing by the image processing unit 40 is performed on the captured image data of the acquired frame, and the captured image data including the luminance signal Y and the color difference signals Cb and Cr is generated. It is stored in the frame memory 41 (S42).

[Image compression processing S43]
Next, the image processing unit 40 reads the photographed image data from the frame memory 41, compresses it with a predetermined encoding method (for example, H.264 format), and then compresses the photographed image data (compressed image data). The buffer memory 42 is temporarily stored (S43).

  In the present embodiment, in order to efficiently use hardware resources such as the image processing unit 40, the recording of moving image data in the auxiliary storage device such as the memory card 61a is not performed in units of frames, but a plurality of frames. Done in units. Specifically, when captured image data of a predetermined number of frames is stored in the buffer memory 42 (or when captured image data is stored for a predetermined period), the image processing unit 40 stores the stored captured image. The management information (header) is added to the data to generate a packet (data block), and the captured image data is recorded in an auxiliary storage device such as the memory card 61a in units of packets.

[Write Size Update S5]
Next, the image processing unit 40 confirms the data amount of the captured image data stored in the buffer memory 42 and adds a packet header size (a representative value if the value is not a fixed value) to the provisional image data. The write size (packet size) is calculated and recorded (overwrite updated) in the general-purpose memory 43 (S5).

[File writing determination S6]
Next, the image processing unit 40 confirms the number of frames of the captured image data stored in the buffer memory 42, and based on the stored number of frames, the image processing unit 40 adds the captured image data to the moving image file created on the memory card 61a. It is determined whether or not writing should be performed (S6). Specifically, if the number of photographed image data (frames) accumulated in the buffer memory 42 has reached a predetermined number, the image processing unit 40 determines that writing should be executed. On the other hand, if the number of frames has not reached the predetermined number, the image processing unit 40 determines that accumulation of the captured image should be continued without writing (S6: NO), and the moving image recording in-process S4 is performed again.

[Remaining capacity excess determination S7]
If it is determined in the file writing determination S6 that writing of the captured image data to the moving image file should be executed (S6: YES), then the writing size calculated in the processing S5 is compared with the remaining capacity of the memory card 61a. Then, the remaining capacity excess determination S7 for determining whether the write size exceeds the remaining capacity of the memory card 61a is performed.

[File writing S8]
If the writing size is less than or equal to the remaining capacity of the memory card 61a (S7: NO), a packet is generated based on the photographed image data of a predetermined number of frames stored in the buffer memory 42, and a moving image file on the memory card 61a. (S12).

[Compression rate representative value calculation S9]
Next, a representative value of the compression rate of the compressed image data stored in the buffer memory 42 is calculated. The representative value of the compression rate is used for updating the recordable time. The representative value of the compression ratio is calculated by, for example, an arithmetic average, a geometric average, a harmonic average, a moving average, a weighted moving average (for example, a larger weight is set for a new value) of the compression ratio of the compressed image data. Alternatively, the median value, mode value, or minimum value of the compression ratio may be used as the representative value. By setting the minimum value of the compression rate as the representative value, the remaining recordable time that can be reliably estimated is obtained. The representative value may be calculated from the compression ratios of all the compressed image data stored in the buffer memory 42, or a predetermined number (for example, the most recently stored in the buffer memory 42 after the photographing apparatus 1 is activated). It may be calculated from the compression rate of the compressed image data of the latest three frames). Alternatively, the representative value may be calculated from the compression rate of the compressed image data stored in the buffer memory 42 within the predetermined time immediately before. Alternatively, the representative value may be calculated from the compression rate of a predetermined number of compressed image data stored most recently among the compressed image data stored in the buffer memory 42 within the predetermined time immediately before.

[Remaining capacity confirmation S10]
Since the remaining capacity of the memory card 61a is changed by the file writing process S8, the remaining capacity is confirmed again (S10).

  Further, the system control unit 10 calculates an estimated value of the remaining time that can be recorded on the memory card 61a (the number of images that can be stored in the memory card 61a when recording a still image) based on the confirmed remaining capacity. The predicted value displayed on the display device 71 is updated by calculation.

  In the remaining capacity confirmation processing S1 performed before the start of moving image recording, a predicted value of the recordable time is calculated based on the predicted compression rate corresponding to the quantization parameter used for image compression. In the remaining capacity confirmation process S11 to be performed, a predicted value of the recordable time is calculated based on the actual measurement value of the compression ratio calculated in the compression ratio representative value calculation S9. Therefore, in the process S9, the predicted value of the recordable time is calculated with higher accuracy than the remaining capacity confirmation process S1.

[Remaining capacity determination S11]
Next, it is determined whether or not the remaining capacity of the memory card 61a confirmed in the remaining capacity confirmation processing S10 is equal to or greater than the minimum capacity suitable for recording the next packet (hereinafter referred to as “movie recording continuation permission capacity”). The remaining capacity determination S11 to be performed is performed. The moving image recording continuation permission capacity is a reference value set in advance for determining whether or not to continue recording of moving image data. In this embodiment, the moving image recording start capacity used in the remaining capacity determination S2 described above is used. The same value as the permitted capacity is applied.

  When the remaining capacity of the memory card 61a is equal to or larger than the moving image recording continuation permission capacity, it is determined that there is a remaining capacity (S11: YES), and the moving image recording in-process S4 is executed again.

[Termination Tag Write S12]
If the remaining capacity of the memory card 61a is smaller than the permitted moving image recording continuation capacity, it is determined that there is no remaining capacity (S11: NO), and the last packet written in the moving image file is the last packet of the stream. An end tag (end code) indicating this is written.

  Further, when it is determined in the remaining capacity excess determination S7 that the write size exceeds the remaining capacity of the memory card 61a (S7: YES), the terminal tag is written.

[Movie recording end process S13]
Next, after updating management information such as the file size included in the header of the moving image file, the moving image file is closed and the moving image recording process is terminated.

  In the moving image recording process according to the embodiment of the present invention described above, a memory card or the like is based on the actual data amount of compressed image data (more precisely, a packet that is a recording unit of moving image data). Therefore, recording of moving image data using the remaining capacity more effectively than the conventional method using the predicted value of the compressed data amount (that is, the same remaining capacity, It is possible to record moving image data for a longer time without increasing the compression rate of the image data and lowering the image quality.

  The above is the description of the exemplary embodiments of the present invention. Embodiments of the present invention are not limited to those described above, and various modifications are possible within the scope of the technical idea of the present invention. For example, the embodiment of the present invention also includes contents appropriately combined with embodiments or the like clearly shown in the specification or obvious embodiments.

  In the above embodiment, image data for one write (one packet) is recorded in the buffer memory 42 in the memory card 61a, but image data for a plurality of writes (for example, two packets) is recorded in the buffer memory 42. It is good also as composition to do. With this configuration, while writing to one packet on the buffer memory 42, other packets can be read and written to the memory card 61a, and packet generation and movement to the memory card 61a can be performed. It becomes possible to carry out efficiently.

  In the above embodiment, one packet is temporarily recorded in the buffer memory 42. However, a plurality of continuous packets are temporarily recorded (accumulated) in the buffer memory 42, and a plurality of continuous packets are stored at a time (or sequentially). It is good also as a structure which writes in auxiliary storage devices, such as a card | curd. Also,

  In the above-described embodiment, information on a plurality of frames in which a packet is continuous (a plurality of captured image data) is included. However, the packet may include information on a single frame. Further, the packet may be obtained by multiplexing voice and other data and captured image data.

  The above embodiment is an example in which the present invention is applied to recording of moving image data. However, the present invention can also be applied to recording of still image data (for example, a compressed image file such as a JPEG format). The present invention can also be applied to recording of other indefinite length data such as audio data and waveform data.

  In addition, the above embodiment is an example of a photographing apparatus in which the image recording apparatus and the imaging apparatus (imaging unit) according to an embodiment of the present invention are integrated, but the image recording apparatus and the imaging apparatus are separated. Alternatively, a wired or wireless connection may be employed. Further, instead of the imaging device, the image recording device of the present invention is connected to a broadcast receiver or a communication device (for example, a node of a computer network) to record image data acquired by data broadcasting or data communication. You can also. Further, the image recording apparatus of the present invention may be connected to a computer to record image data of a computer graphics image created by the computer.

DESCRIPTION OF SYMBOLS 1 Imaging device 10 System control part 20 Imaging part 40 Image processing part 61 Memory card interface 61a Memory card 62 Flash memory 92 Operation part

Claims (10)

Image acquisition means for acquiring image data;
Image compression means for generating recording data including compressed image data obtained by compressing the image data;
Recording means for recording the recording data in a storage medium;
Free space confirmation means for confirming the free space of the storage medium;
A record enable / disable determining means for comparing the data amount of the generated record data with the free capacity to determine whether the record data can be recorded on the storage medium;
An image recording apparatus comprising: A degree-of-compression setting means for setting a degree of compression that defines the degree of data compression;
Compression rate calculation means for calculating a representative value of the compression rate of the compressed image data generated after the image recording device is activated;
Recordable image amount prediction means for calculating a predicted value of the number of still images or the length of a moving image that can be recorded in the recording means based on the free space;
Display means for displaying the predicted value;
Further comprising
The recordable image amount predicting means,
If the compressed image data has not been generated after the image recording device is activated, the predicted value is calculated based on the free space and the compression degree,
When the compressed image data is generated after the image recording device is activated, the predicted value is calculated based on the free capacity and a representative value of the compression rate.
The image recording apparatus according to claim 1. The compression rate calculation means
Calculating a representative value of the compression rate based on a compression rate of a predetermined number of the compressed image data generated most recently after starting the image recording apparatus;
The image recording apparatus according to claim 2. The compression rate calculation means
Calculating a representative value of the compression ratio based on the compression ratio of the compressed image data generated within a predetermined time immediately after the image recording apparatus is activated;
The image recording apparatus according to claim 2. Temporary storage means for temporarily storing the recording data,
The record availability determination means is
Comparing the data amount of the recording data stored in the temporary storage means and the free capacity to determine whether the recording data can be recorded in the recording means;
The image recording apparatus according to any one of claims 1 to 4. The recording data is moving image data generated from a plurality of the compressed image data stored in the temporary storage means;
The recording means records the recording data on the storage medium in a reproducible unit;
The image recording apparatus according to claim 5. The image data is frame data constituting moving image data,
The recording data is a packet constituting a file in which the moving image data is stored.
The image recording apparatus according to claim 5. The recording means is
A tag indicating that it is the last data unit is added to the recording data recorded last on the storage medium when the recording permission determination unit determines that recording is impossible;
The image recording apparatus according to claim 6 or 7. Imaging means for imaging a subject and generating the image data;
The image recording apparatus according to any one of claims 1 to 8,
An imaging apparatus comprising: An image acquisition step for acquiring image data;
An image compression step of generating recording data including compressed image data obtained by compressing the image data;
A free space confirmation step for confirming the free space of the storage medium;
A recordability determination step of comparing the data amount of the generated recording data and the free space to determine whether the recording data can be recorded on the storage medium;
A recording step of recording the recording data in a storage medium when it is determined that recording is possible in the recording possibility determination step;
An image recording method comprising:

Images