JP7228826B2 - Video recording device - Google Patents

Description

The present disclosure relates to a video recording device.

As a video recording device, a drive recorder that records video data in a storage unit while changing the compression ratio and frame rate based on acceleration detected by an acceleration sensor is already known (see, for example, Patent Document 1).

JP 2010-146477 A

The inventor of the present invention intends to provide a drive recorder with a function of monitoring surroundings during parking as a countermeasure against crimes such as theft and hit-and-run. Specifically, the idea is to record the video taken while the vehicle is parked as video data in the storage unit of the drive recorder. However, it is difficult to constantly record high-quality captured images while the vehicle is parked for a relatively long time due to the storage capacity of the storage unit.

Therefore, according to one aspect of the present disclosure, it is desirable to be able to provide a technology that can advantageously record images captured by a camera while the vehicle is parked.

According to one aspect of the present disclosure, a video recording device mounted on a vehicle is provided. The video recording device comprises a generating unit, a video recording unit and a control unit. The generating unit is configured to generate video data for recording representing video captured by the camera, based on a video signal from the camera capturing the surroundings of the vehicle while the vehicle is parked. The video recording unit is configured to store the video data generated by the generating unit in the storage unit.

The control unit analyzes the image captured by the camera and controls the image quality of the image data generated by the generation unit based on changes in the image, thereby controlling the amount of image data stored in the storage unit by the image recording unit. configured to By controlling the video quality based on the video changes identified from the captured video, it is possible to advantageously utilize the limited storage area and record the video captured by the camera while the vehicle is parked.

According to one aspect of the present disclosure, the control unit may be configured to control video quality of the video data by controlling at least one of compression rate and frame rate of the video data generated by the generation unit. good.

According to one aspect of the present disclosure, the control unit changes the video quality of the video data generated by the generation unit from a first quality to a higher than the first quality on the condition that a video change that satisfies a predetermined condition occurs. The video quality of the video data may be controlled by temporarily changing to a second quality. By controlling the image quality in this way, it is possible to suppress unnecessary recording of motionless images with relatively simple processing, and it is possible to advantageously record images captured by the camera while the vehicle is parked. Temporarily changing can be changing the video quality of the video data to the second quality only for a predetermined period of time.

According to one aspect of the present disclosure, the video recording device may include an impact detection unit that detects impact. In this case, the control unit may control the video quality of the video data based on the video changes and the shocks detected by the shock detection unit. Specifically, the control unit may be configured to temporarily change the image quality of the image data from the first quality to the second quality on condition that an impact is detected. According to this example, it is possible to record a high-quality photographed image when an impact occurs while suppressing the amount of image recording while the vehicle is parked, and it is possible to meaningfully record a surveillance image around the vehicle.

The control unit changes the image quality of the image data to the second quality on the condition that an image change that satisfies a predetermined condition occurs, and then maintains the image quality of the image data at the second quality for a certain period of time. After the elapse of time, the image quality of the image data is returned to the first quality, and if an impact is detected before the elapse of a certain period of time, the image quality of the image data is returned to the second quality. It may be configured to extend the duration of maintenance.

According to one aspect of the present disclosure, a storage unit may have a first area and a second area. The control unit stores, among the image data generated by the generation unit, image data representing a captured image of a period related to the impact detected by the impact detection unit in the first area, and stores other image data in the first area. It may be configured to store in a second area. According to this method, videos of high importance can be recorded separately from videos of low importance. Therefore, it is possible to prevent the storage of high-importance video data from being hindered by, for example, low-importance video data, and to facilitate access to high-importance video data.

The control unit generates, among the video data generated by the generation unit, the video data generated with the second quality on the condition that the impact is detected, and the video that satisfies the predetermined condition before the shooting period of the video. and at least part of the video data representing the captured video from the time of occurrence of the change to the start point of the shooting period, as video data representing the captured video during the period related to the impact, in the first area. may According to this method, it is possible to appropriately store in the first area image data that may include images of actions related to the impact before the impact occurs.

The video recording device may comprise a camera as described above. The video recording device may include a camera that captures an image in front of the vehicle and may be configured to function as a drive recorder. The function as a video recording device may be incorporated in a drive recorder equipped with a camera that captures images in front of the vehicle.

It is a block diagram showing the structure of a drive recorder. 4 is a flowchart showing video change detection processing executed by a video analysis unit; FIG. 4 is a diagram showing divided regions within a frame; 4 is a flowchart showing mode switching processing executed by a video recording unit; 4 is a flowchart showing write control processing executed by a video recording unit; 6A-6C are diagrams illustrating mode switching manners and write areas.

Exemplary embodiments of the present disclosure are described below with reference to the drawings.
A drive recorder 1 according to the present embodiment shown in FIG. 1 is fixed in a vehicle interior and arranged so as to be able to photograph the surroundings of the vehicle, especially the front of the vehicle through the windshield. This drive recorder 1 includes a camera 10 , an acceleration sensor 20 , a control device 30 , a card slot 40 , a memory card 50 , an internal clock 60 , a user interface 70 and a work memory 80 .

The camera 10 is configured to capture an image in front of the vehicle and input a video signal representing the captured image to the control device 30 . The acceleration sensor 20 is configured to detect acceleration of the drive recorder 1 and input an acceleration signal representing the detected value to the control device 30 . The acceleration sensor 20 is, for example, a three-axis acceleration sensor 20, and is arranged so as to detect acceleration in the longitudinal, lateral, and vertical directions of the vehicle.

Based on the video signal from the camera 10, the control device 30 generates video data for recording representing a photographed video in front of the vehicle, and records the generated video data in the memory card 50 attached to the card slot 40. configured to Video data is temporarily stored in the work memory 80 until it is recorded in the memory card 50 . The memory card 50 is a small flash memory having the shape of a card, and an example of the memory card 50 includes an SD card (registered trademark). A memory card 50 is prepared to store video data and is loaded into the card slot 40 .

The user interface 70 includes key switches for accepting user operations, and speakers for outputting guidance voices and notification sounds to the user. The control device 30 is configured to perform an operation according to an instruction from a user based on an input signal from a key switch, and output guidance voice and notification sound to the user through a speaker.

As shown in FIG. 1, the control device 30 includes a data processing section 31, an impact detection section 35, and a video recording section 37. As shown in FIG. The control device 30 may include the data processing unit 31, the impact detection unit 35, and the video recording unit 37 as dedicated circuits, or the data processing unit 31, the impact detection unit 35, and the video recording unit 37. may be configured to be realized in software by executing a program by a general-purpose processor. The data processing unit 31, impact detection unit 35, and video recording unit 37 can be realized by a combination of hardware and software.

The data processing unit 31 compresses the video signal from the camera 10 to generate video data for recording, and analyzes the video captured by the camera 10 to detect a moving object in the video.

Specifically, the data processing section 31 includes an encoding section 32 and a video analysis section 33 . The encoding unit 32 is configured to encode the video signal from the camera 10 in a predetermined compression format to generate compressed video data for recording. According to this embodiment, the compression rate and frame rate of the video data generated by the encoding unit 32 are switched by the video recording unit 37 .

According to this embodiment, in order to reduce the amount of video data recorded on the memory card 50, less important video data has a lower video quality with high compression and a low frame rate. is generated as video data with less importance, and video data with high importance is generated as video data with a large amount of data per hour, which has higher video quality with lower compression and a higher frame rate than video data with lower importance. . In order to determine whether the degree of importance is high or low, the video analysis unit 33 analyzes the video captured by the camera 10, and the impact detection unit 35 detects the impact.

The video analysis unit 33 is configured to detect a moving object in the video by referring to the video signal from the camera 10 and detecting a video change that satisfies a predetermined condition. Various techniques are known as image change detection techniques for detecting a moving object appearing in an image. The video analysis unit 33 can detect a moving object appearing in the video using this technique.

For example, the video analysis unit 33 can detect a moving object appearing in the video by calculating the correlation coefficient R regarding the luminance distribution between frames in time series. Specifically, the video analysis unit 33 can execute the video change detection process shown in FIG. 2 each time a video signal of a new frame is input.

In the video change detection process, the video analysis unit 33 selects one of the four divided regions R1 to R4 in the latest frame according to a predetermined rule (S110). The four regions within the frame are shown in FIG. As indicated by the arrows in FIG. 3, the predetermined rule is to repeatedly select the regions R1 to R4 in order, such as region R1, region R2, region R3, region R4, region R1, region R2, region R3, region R4. Corresponds to the rule that Only one region is selected for one frame.

After selecting one of the regions R1 to R4 in S110, the video analysis unit 33 evaluates the luminance distribution of the selected region (S120). In this embodiment, the captured image is expressed in the YCaCb color space. The video analysis unit 33 calculates the average value YA of the luminance value Y of each pixel in the selected region as the luminance distribution evaluation value, and further calculates the difference (Y−YA) between the luminance value Y of each pixel and the average value YA. is calculated, and furthermore, the variance D of the brightness Y in the selected region is calculated.

After that, the video analysis unit 33 performs a non-linear image analysis with respect to the selected region based on the evaluation value calculated in S120 and the evaluation value of the previous frame (specifically, the frame four frames before) calculated for the same region. The level of video change is evaluated (S130). Specifically, the video analysis unit 33 can calculate the correlation coefficient R between the luminance distribution of the latest frame and the luminance distribution of the previous frame as the level of video change. As is well known, the correlation coefficient R is calculated using the covariance of the brightness value Y between the latest frame and the previous frame, the variance of the brightness value Y of the latest frame, and the variance of the brightness value Y of the previous frame. can do.

After that, the image analysis unit 33 determines whether or not the image change is large by comparing the level of the image change evaluated in S130, specifically the correlation coefficient R, with a threshold value (S140). As is well known, the correlation coefficient R indicates a high value when the linearity of the luminance distribution between two frames is strong, and indicates a low value when the nonlinearity is strong. The non-linearity of the luminance distribution implies the presence of moving objects in the corresponding images.

Therefore, when the correlation coefficient R is less than the threshold value, the image analysis unit 33 determines that the image change is large (Yes in S140), and when the correlation coefficient R is the threshold value or more, the image analysis unit 33 determines that the image change is small. (No in S140). When the image analysis unit 33 determines that the image change is large in this way, it turns on the image change occurrence flag (S150), and when it determines that the image change is small, it turns off the image change occurrence flag (S160). ). The image change occurrence flag is referred to by the image recording unit 37 as an analysis result of the captured image by the image analysis unit 33 .

The image analysis unit 33 repeatedly executes the above-described processing of S110 to S160 to evaluate the image change in a partial area within the latest frame for each input of the image signal of the latest frame.

Further, the impact detection unit 35 is configured to determine whether or not an impact has occurred to the drive recorder 1 based on the acceleration signal from the acceleration sensor 20, and to turn on/off an impact occurrence flag. be. The impact of the drive recorder 1 basically corresponds to the impact acting on the vehicle. The impact generation flag is referred to by the video recording unit 37 as the impact detection result of the impact detection unit 35 .

Specifically, when the absolute value of the acceleration indicated by the acceleration signal is equal to or greater than a predetermined threshold value, the impact detection unit 35 detects that an impact has occurred, sets the impact occurrence flag to ON, and detects the occurrence of the impact. Otherwise, the impact occurrence flag can be reset to off.

The image recording unit 37 refers to the impact occurrence flag to determine that an impact has been detected by the impact detection unit 35, and refers to the image change occurrence flag to detect an image change that satisfies a predetermined condition. The occurrence is determined, and the compression rate and frame rate of the video data generated by the encoding unit 32 are controlled according to the occurrence of impact and video change.

The drive recorder 1 of this embodiment has a function of monitoring surroundings during parking. This perimeter monitoring function is realized by storing the image captured by the camera 10 in the memory card 50 as reproducible image data while the vehicle is parked. By attaching a sticker or the like to the vehicle indicating that the drive recorder 1 has a surroundings monitoring function, the presence of the surroundings monitoring function can be appealed and used to deter crime.

However, the normal parking time is much longer than the time the vehicle is driven, and it is difficult to store high-quality video data with low compression and high frame rate in the memory card 50 while the vehicle is parked. It is difficult because of memory capacity.

If high-quality video data is constantly generated while the vehicle is parked and written to the memory card 50, the memory capacity of the memory card 50 will soon run out, making it impossible to store the video data or overwriting the old video data. It becomes necessary to write new video data to the memory card 50 like this. In this case, there is a high possibility that video data of high importance during parking, especially video data showing acts such as theft and hit-and-run that occur while parking, cannot be properly stored.

In the present embodiment, in order to appropriately record such video data to the memory card 50 while parking, the video recording unit 37 controls the compression ratio and Control frame rate. Specifically, the video recording unit 37 changes the operation mode of the encoding unit 32 from a normal mode in which video data is generated with high compression and a low frame rate to a low compression and high frame rate mode temporarily as necessary. It operates to switch to a high quality mode where video data is generated at a rate.

The video recording unit 37 is configured to repeatedly execute the mode switching process shown in FIG. 4 while the vehicle is parked, and to repeatedly execute the writing control process shown in FIG. The drive recorder 1 is wired so as to receive a parking signal from the vehicle. The video recording unit 37 determines whether the vehicle is parked according to the parking signal, and determines whether the vehicle is parked. repeats the processes shown in FIGS.

When the video recording unit 37 starts the mode switching process shown in FIG. 4 while the vehicle is parked, the video recording unit 37 determines whether or not the encoding unit 32 is set to the normal mode (S210). The operation modes of the encoding unit 32 during parking include the normal mode and the high quality mode, as described above. The operation mode at the start of the perimeter monitoring function that operates with the start of parking is the normal mode. The normal mode is an operation mode in which the encoding unit 32 generates video data for recording with high compression and a low frame rate. The high quality mode is an operation mode in which the encoding unit 32 generates video data for recording with low compression and a high frame rate. The compression rate and frame rate of each mode are determined in advance at the design stage.

When the video recording unit 37 determines that the operation mode is the normal mode (Yes at S210), it proceeds to S220, and when it determines that the operation mode is the high quality mode (No at S210), it proceeds to S250.

In S<b>220 , the video recording unit 37 refers to the video change occurrence flag in the video analysis unit 33 to determine whether or not a video change that satisfies a predetermined condition has occurred. If it is determined that a video change has occurred (Yes at S220), the process proceeds to S240 and sets the operation mode of the encoding unit 32 to the high quality mode.

If it is determined that no image change has occurred (No in S220), the image recording unit 37 refers to the impact occurrence flag in the impact detection unit 35 to determine whether or not an impact has occurred (S230). . When it is determined that an impact has occurred (Yes in S230), the process proceeds to S240 and sets the operation mode of the encoding unit 32 to the high quality mode.

That is, when the operation mode of the encoding unit 32 is in the normal mode, the image recording unit 37 switches the operation mode to the high quality mode when an image change satisfying a predetermined condition occurs or when an impact occurs ( S240). After that, the video recording unit 37 sets the switching timing from the high quality mode to the normal mode (S245). For example, the video recording unit 37 sets the switching timing to the normal mode to a predetermined time TA from now. An example of the predetermined time TA includes 1 minute. The video recording unit 37 can operate to set the switching timing by setting the value of the countdown timer to a value corresponding to the predetermined time TA. After setting the switching timing, the video recording unit 37 temporarily terminates the mode switching process.

In the normal mode, if neither image change nor impact has occurred (No in S220 and No in S230), the video recording unit 37 maintains the operation mode of the encoding unit 32 in the normal mode, and performs mode switching processing. is terminated once.

Since the operation mode of the encoding unit 32 is in the high quality mode, the video recording unit 37 refers to the impact generation flag in the impact detection unit 35 to determine whether or not a new impact has occurred when the process proceeds to S250. to judge whether If a negative determination is made here (No in S250), the video recording unit 37 proceeds to S260.

On the other hand, when the video recording unit 37 determines that a new impact has occurred (Yes in S250), it executes processing for extending the switching timing to the normal mode (S255), and then proceeds to S260.

According to the first example, in S255, the video recording unit 37 executes processing for delaying the switching timing by a predetermined time TB by updating the value of the countdown timer to a value corresponding to the predetermined time TB. can be done. The predetermined time TB may be 1 minute, which is the same as the predetermined time TA described above.

According to the second example, in S255, the video recording unit 37 returns the value of the countdown timer that is decremented with the passage of time to the value set in S245 (the value corresponding to the predetermined time TA), thereby returning to the normal mode. can be extended from the present to a predetermined time TA later.

In addition, the video recording unit 37 makes an affirmative determination in S250 only for the first impact that occurred during the high-quality mode, makes a negative determination in S250 for the second and subsequent impacts, and performs the processing of S255 to determine whether the impact occurred. It may be configured not to repeat every time.

After shifting to S260, the video recording unit 37 determines whether or not the timing for switching to the normal mode has arrived. For example, it determines whether the countdown timer value has reached zero. When it is determined that the switching timing has arrived (Yes in S260), the video recording unit 37 refers to the video change occurrence flag in the video analysis unit 33 to determine whether a video change that satisfies a predetermined condition has occurred at the present time. (S270).

If it is determined that no video change has occurred (No in S270), the video recording section 37 proceeds to S280 and returns the operation mode of the encoding section 32 to the normal mode. After that, the video recording unit 37 once terminates the mode switching process. On the other hand, if it is determined that an image change has occurred (Yes in S270), the image recording unit 37 executes the processing for extending the switching timing in the same manner as the processing in S255 (S290). Terminate the process once.

By executing the mode switching process in this manner, the image recording unit 37, for example, when an image change that satisfies a predetermined condition occurs during parking, the encoding unit 32 changes the is changed from the normal mode to the high quality mode, and after a predetermined time TA has passed, the operation mode is changed to the normal mode. As a result, the video recording unit 37 temporarily changes the operation mode of the encoding unit 32 to the high-quality mode on the condition that the video changes, so that the encoding unit 32 generates high-quality video data. . Similarly, as shown in FIG. 6C, when an impact is detected during parking, the video recording unit 37 temporarily changes the operation mode of the encoding unit 32 from the normal mode to the high-quality mode, The conversion unit 32 is configured to generate high-quality video data.

Further, as shown in FIG. 6B, after the encoding unit 32 starts operating in the high-quality mode due to a video change, if an impact is detected before the predetermined time TA elapses, the video recording unit 37 selects the high-quality mode. It operates to extend the mode for a predetermined time TB.

The video recording unit 37 writes the video data generated by the encoding unit 32 to the memory card 50 in the write control process executed in parallel with the mode switching process as follows. When the writing control process shown in FIG. 5 is started, the video recording unit 37 refers to the impact occurrence flag in the impact detection unit 35 to determine whether or not an impact has occurred (S310). When it is determined that an impact has not occurred (No in S310), the process proceeds to S320, and when it is determined that an impact has occurred (Yes in S310), the event flag is set to ON (S315), and the process proceeds to S320. do. The event flag is initialized off at the start of the perimeter watch function.

In S320, the video recording unit 37 determines whether or not the operation mode of the encoding unit 32 is the normal mode. Then, when it is determined that the mode is the high quality mode (No in S320), the write control process is terminated. On the other hand, if it is determined that the operation mode of the encoding unit 32 is the normal mode (Yes in S320), the video recording unit 37 waits for a certain period of time after the operation mode of the encoding unit 32 switches from the high quality mode to the normal mode. It is determined whether or not it has passed (S330). When it is determined that the predetermined time has not elapsed (No in S330), the write control process is once terminated.

When the video recording unit 37 determines that the predetermined time has passed in S330 (Yes in S330), it determines whether or not the predetermined time has passed (S340). Then, if it is determined that a certain period of time has just elapsed since the operation mode of the encoding unit 32 was switched to the normal mode (Yes in S340), the video recording unit 37 proceeds to S350, and if it determines that it is not immediately after (No in S340), the process proceeds to S380.

In S350, the video recording unit 37 determines whether or not the event flag is set to ON. Then, when it is determined that the event flag is set to ON (Yes in S350), the continuous operation period of the high quality mode ending at the end point of the high quality mode which ended before the certain period of time is specified and specified. The video data representing the captured video from the start point to the end of the continuous operation period is written as one recording file in the event area prepared in advance in the memory card 50 (S360).

The continuous operation period referred to here is a period in which one or more operation periods exist in the high-quality mode, and the operation period in the normal mode between adjacent operation periods in the high-quality mode is less than a predetermined time TC. is the period. Predetermined time TC may be, for example, one minute, which is the same as predetermined times TA and TB described above.

According to one example, the continuous operation period corresponds to a period during which the encoder 32 continuously operates in the high quality mode from its beginning to its end.
According to one example, the period of continuous operation, whose starting point is the time of switching from normal mode to high quality mode and whose end is the time of switching from high quality mode to normal mode, has a period of high This is a period that includes two or more quality mode operation periods and includes normal mode operation periods that are less than the predetermined time TC, one less than the high quality mode operation period. In this case, one recording file contains low-quality and high-quality video data corresponding to the captured video during the continuous operation period.

As shown in FIG. 6C, the encoding unit 32 operates in the high quality mode due to the video change, and then the encoding unit 32 temporarily operates in the normal mode. 32 operates in the high-quality mode again, the period of operation in the normal mode extends from the beginning of the period of operation in the high-quality mode caused by the video change to the end of the period of operation in the high-quality mode caused by the shock. is included. At S360, all the video data in the continuous operation period including the normal mode operation period are written in the event area as one recording file.

Note that the continuous operation period corresponding to the video data written as one recording file in the event area in S360 always includes a period during which the encoding unit 32 operates in the high quality mode due to the impact.

After completing the processing in S360, the video recording unit 37 sets the event flag to OFF (S365), and then temporarily terminates the writing control processing.
On the other hand, if the video recording unit 37 determines that the event flag is set to OFF in S350 (No in S350), the video recording unit 37 continues recording in the high quality mode ending at the end point of the high quality mode that ended a certain period of time ago. An operation period is specified, and video data representing a photographed image from the start point to the end of the specified continuous operation period is written as one recording file in a non-event area prepared in advance in the memory card 50 (S370). After that, the video recording unit 37 temporarily terminates the write control process.

In this embodiment, when the memory card 50 is formatted, an event area and a non-event area are secured within the memory area of the memory card 50 . Here, at least the event area is secured as a fixed size area.

The continuous operation period corresponding to the video data written as one recording file in the non-event area in S370 includes the period during which the encoding unit 32 operates in the high quality mode due to the occurrence of video changes. The period during which the encoding unit 32 operates in the high quality mode due to the occurrence of is not included. In this respect, the recorded file written to the non-event area at S370 differs from the recorded file written to the event area at S360.

In addition, when making a negative determination in S340 and proceeding to S380, the video recording unit 37 determines whether or not the conditions for writing the video data to the memory card 50 are satisfied. Here, the image recording unit 37 determines that the write condition is satisfied when the amount of unwritten image data in the memory card 50 exceeds a predetermined amount, and writes when the amount is equal to or less than the predetermined amount. It can be determined that the condition is not satisfied.

Alternatively, the video recording unit 37 determines that the write condition is satisfied when a predetermined time TD has passed since the video data was last written to the memory card 50, and if the predetermined time TD has not passed, , it can be determined that the write condition is not satisfied.

When the video recording unit 37 determines that the writing condition is not satisfied (No in S380), the writing control process is once terminated. On the other hand, when the video recording unit 37 determines that the write condition is satisfied (Yes in S380), it writes the video data that has not yet been written to the memory card 50 as one recording file in the non-event area of the memory card 50 ( S390), after which the write control process is terminated.

In S360, S370, and S390, when writing a recorded file to the memory card 50, if there is no free space in the area to be written, the video recording unit 37 overwrites the oldest recorded file in the area to be written. You can write a new recording file just like you do.

When the video recording unit 37 executes the write control process in this way, as illustrated in FIGS. 6A to 6C, only the video in the continuous operation period of the high quality mode including the impact occurrence event is recorded in the event area. Images in other periods are recorded in the non-event area.

If the drive recorder 1 receives an impact while the vehicle is parked, there is a high possibility that the vehicle has been stolen or hit and run. Therefore, according to the present embodiment, important video data, which is highly likely to contain video of theft or hit-and-run, is distinguished from other video data so as not to be overwritten by unimportant video data. can be recorded in the memory card 50 at any time.

The drive recorder 1 of the present embodiment has been described above. According to the present embodiment, the camera 10 of the drive recorder 1 can be effectively used to realize monitoring of the surroundings during parking. In particular, according to the present embodiment, the image quality of the image data for recording, specifically the compression rate and frame rate, is controlled depending on whether or not the image of the camera 10 changes. Furthermore, the image quality of the image data is controlled depending on the presence or absence of impact. Therefore, while it is possible to store high-importance video that meets the purpose of monitoring in the memory card 50 as high-quality video data, the data amount of low-importance video data can be suppressed and these video data can be stored in the memory. It can be efficiently stored in the card 50.

In particular, according to this embodiment, as shown in FIG. 3, a frame is divided into a plurality of regions R1 to R4, video analysis is performed only on selected regions for each frame, and video changes are detected. Therefore, according to the present embodiment, it is possible to efficiently detect image changes in the entire imaging area while suppressing the load of image analysis.

Furthermore, according to this embodiment, the captured image when the impact is detected is recorded in the event area. Record in the event area as one recording file. Therefore, according to the present embodiment, while the camera 10 that captures only a limited area in front of the vehicle surroundings is used for monitoring the surroundings of the vehicle, high-quality images related to the impact can be captured from before the impact. can be properly recorded as

It goes without saying that the present disclosure is not limited to the above-described embodiments and can take various forms. The technology of the present disclosure can be applied to video recording devices other than drive recorders. The technology of the present disclosure may be applied to a video recording device that records video around the vehicle using a camera mounted on the vehicle for driving assistance or automatic driving.

In addition, in the above embodiment, in S360, the video data of the continuous operation period in the high-quality mode is stored in the event area as a recording file containing high-quality video data and low-quality video data. Data, ie, data relating to images captured in normal mode, may be recorded in the non-event area separately from high-quality image data during continuous operation.

A function possessed by one component in the above embodiment may be distributed to a plurality of components. Functions possessed by multiple components may be integrated into one component. A part of the configuration of the above embodiment may be omitted. At least part of the configurations of the above embodiments may be added or replaced with respect to the configurations of other above embodiments. All aspects included in the technical ideas specified by the language in the claims are embodiments of the present disclosure.

Finally, the correspondence between terms will be explained. The memory card 50 corresponds to an example of a storage unit, the encoding section 32 corresponds to an example of a generation unit, and the shock detection section 35 corresponds to an example of a shock detection unit. In addition, the function realized by the write control process executed by the video recording unit 37 corresponds to an example of the function realized by the video recording unit. A function realized by the mode switching process to be executed corresponds to an example of a function realized by the control unit.

Reference Signs List 1 drive recorder 10 camera 20 acceleration sensor 30 control device 31 data processing unit 32 encoding unit 33 video analysis unit 35 shock detection unit 37 video recording unit 50 …Memory card.

Claims (6)

A video recording device mounted on a vehicle,
a generation unit configured to generate, based on a video signal from a camera that captures the surroundings of the vehicle while the vehicle is parked, video data for recording representing a video captured by the camera;
a video recording unit configured to store the video data generated by the generating unit in a storage unit;
an impact detection unit that detects an impact;
a control unit configured to analyze an image captured by the camera and control image quality of the image data generated by the generation unit based on changes in the image;
with
The control unit changes the video quality of the video data generated by the generation unit from a first quality to a second quality higher than the first quality on condition that a video change that satisfies a predetermined condition occurs. temporarily changing the image quality of the image data generated by the generation unit to the image quality of the image data generated by the generation unit on the condition that the impact is detected when the image change that satisfies the predetermined condition does not occur; controlling the video quality of the video data by temporarily changing from quality to the second quality ;
The video recording unit is
In the first case where the impact is detected after the occurrence of the image change satisfying the predetermined condition, the image data generated with the second quality on the condition that the image change satisfying the predetermined condition occurs. storing the video data including the captured video at the time when the impact was detected in a specific area of the storage unit as video data representing the captured video during a period related to the impact ;
In a second case where the impact is detected without occurrence of an image change that satisfies the predetermined condition, the video data generated with the second quality on the condition that the impact is detected is transferred to the Stored in the specific area as video data representing a captured video of a period related to the impact,
In the first case, the starting point of the period related to the impact corresponds to the point in time when the image change satisfying the predetermined condition occurs, and in the second case, corresponds to the point in time when the impact is detected,
A video recording device in which video data representing a captured video from the starting point is stored in the specific area . A video recording device mounted on a vehicle,
a generation unit configured to generate, based on a video signal from a camera that captures the surroundings of the vehicle while the vehicle is parked, video data for recording representing a video captured by the camera;
a video recording unit configured to store the video data generated by the generating unit in a storage unit;
an impact detection unit that detects an impact;
a control unit configured to analyze an image captured by the camera and control image quality of the image data generated by the generation unit based on changes in the image;
with
The control unit changes the video quality of the video data generated by the generation unit from a first quality to a second quality higher than the first quality on condition that a video change that satisfies a predetermined condition occurs. temporarily changing the image quality of the image data generated by the generation unit to the image quality of the image data generated by the generation unit on the condition that the impact is detected when the image change that satisfies the predetermined condition does not occur; configured to temporarily change from quality to said second quality;
The storage unit has a first area and a second area,
The video recording unit is
Among the image data generated by the generation unit, image data representing a captured image during a period related to the impact detected by the impact detection unit is stored in the first area, and other image data is stored. is configured to be stored in the second area,
When the impact is detected without the occurrence of an image change that satisfies the predetermined condition, the image data representing the captured image during the period related to the impact is set to the second quality after the impact is detected. storing the generated video data in the first area;
When the impact is detected after the occurrence of the image change that satisfies the predetermined condition, the image data representing the captured image during the period related to the impact is set to the second quality after the impact is detected. The generated image data and the image data representing the captured image from the time of occurrence of the image change that satisfies the predetermined condition before the image capturing period to the start point of the image capturing period are combined into the first area. Video recording device to store in. The storage unit has a first area and a second area,
The image recording unit stores, among the image data generated by the generation unit, image data representing a captured image of a period related to the impact in the first area as the specific area, and stores the other image data. 2. The video recording apparatus according to claim 1 , wherein video data is stored in said second area. The control unit changes the video quality of the video data generated by the generation unit to the second quality on the condition that a video change satisfying the predetermined condition occurs, and then changes the video quality of the video data. The second quality is maintained for a certain period of time, and after the certain period of time has passed, the video quality of the video data is returned to the first quality, and the impact occurs before the certain period of time has passed. 4. The video recording apparatus according to any one of claims 1 to 3, wherein, when detected, the time for maintaining the video quality of the video data at the second quality is extended. 5. The control unit controls the image quality of the image data by controlling at least one of a compression rate and a frame rate of the image data generated by the generation unit. 3. A video recording device according to claim 1. 6. The video recording apparatus according to any one of claims 1 to 5 , comprising a camera for photographing the front of the vehicle as the camera, and configured to function as a drive recorder.

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