JP6111595B2 - RECORDING CONTROL DEVICE, RECORDING CONTROL PROGRAM, AND RECORDING CONTROL METHOD - Google Patents

Description

  The present invention belongs to the technical fields of a recording control device, a recording control program, and a recording control method. More specifically, for example, a recording control apparatus and a recording control method for performing recording control when recording image data corresponding to an image captured by a camera such as a video camera on a recording medium, and a program technique for the recording control apparatus Belonging to the field.

  In a crime prevention system generally used for crime prevention in facilities, etc., desired monitoring or the like is performed using images captured by a plurality of video cameras, and image data corresponding to the captured images is recorded for a certain period of time. Is done.

  Here, when all the image data obtained from a plurality of video cameras are recorded, for example, a recorder (including a separate recording medium) must be connected to each video camera. There is a problem that it becomes expensive and operation / maintenance becomes complicated.

  Therefore, as a conventional technique considering this problem, for example, there is a technique disclosed in Patent Document 1 below. In the technique disclosed in Patent Document 1, a plurality of video signals obtained from a plurality of video cameras are alternatively switched sequentially and sent to the same recording apparatus and sequentially recorded on the same recording medium. ing. In this case, a configuration is also disclosed in which the identification signals of a plurality of video signal generators are recorded together with the video signals so as to be convenient for reproduction. According to the technique disclosed in Patent Document 1, image data output from a plurality of video cameras can be recorded on one recording medium as one image stream by alternately and sequentially switching image data. As a result, the cost of the entire crime prevention system can be reduced.

Japanese Patent Laid-Open No. Sho 62-14587 (FIG. 1 etc.)

  However, with the technique disclosed in Patent Document 1, image data from a video camera other than the image data recorded at that time cannot be recorded due to its principle. Therefore, as a result, depending on the switching timing of the video camera, there is a problem that image data important as a security system may not be recorded. This is a very big problem considering the purpose of the security system.

  Therefore, the present invention has been made in view of the above-described problems, and one example of the problem is a recording control apparatus and a recording control method that can prevent recording of important image data from being recorded as a crime prevention system, and the recording control method. The object is to provide a program for a recording control apparatus.

In order to solve the above-mentioned problem, the invention according to claim 1 is an acquisition of a switching unit or the like that acquires image information corresponding to images respectively captured by imaging means such as a plurality of cameras from each of the imaging means. And a compression means such as an encoder for compressing each image information, and sequentially switching each acquired image information to output to the compression means, and the compressed image information is less than the number of the imaging means. A recording unit such as a recording unit that sequentially records on a plurality of recording media, and the importance of each acquired image information is calculated for each imaging unit based on a quantization coefficient used for compression of each image information Based on the calculation means such as an importance calculation unit and the calculated importance, the recording is performed such that the image information having a higher importance has a longer imaging time in the image information recorded on the recording medium. And a control means of the switching controller for controlling the stage.

In order to solve the above-described problem, the invention according to claim 4 is an acquisition of a switching unit or the like that acquires image information corresponding to images captured by imaging units such as a plurality of cameras from each of the imaging units. A computer included in a recording control apparatus comprising: a compression unit that compresses each of the image information; and sequentially outputs the acquired image information to the computer that functions as the compression unit by switching the acquired image information. Recording means for sequentially recording information on a smaller number of recording media than the number of the imaging means, and the degree of importance of each acquired image information based on the quantization coefficient used for compression of each image information Based on the calculated importance calculated for each means, and the image information having a higher importance based on the calculated importance, the image information recorded on the recording medium Control means for controlling said recording means such that the image takes a long time, to function as a.

In order to solve the above-described problem, the invention according to claim 5 is to obtain a switching unit or the like that obtains image information corresponding to images respectively taken by imaging means such as a plurality of cameras from each imaging means. In a recording control method executed in a recording control apparatus comprising: a compression step for compressing each image information; and switching each acquired image information to sequentially output to the compression step, and each image information after compression and a recording step of sequentially recording the number of the recording medium less than the number of the imaging means, the imaging based on the importance of each of the acquired image information, the quantization coefficients used for the compression of each of the image information Based on the calculation step calculated for each means and the calculated importance, the image information having a higher importance has a longer imaging time in the image information recorded on the recording medium. Controlling the recording on the recording medium so as to include a control step.

According to the invention according to any one of claims 1, 4, and 5 , based on the importance of the image information calculated for each imaging unit, the higher the importance of the image information, the longer the imaging time. Since the recording is controlled so as to become longer, it is possible to effectively prevent omission of recording of highly important image information.
In addition, since the importance is calculated for each imaging unit based on the quantization coefficient used for compression of each image information, even when the image information is compressed and recorded, the quantization coefficient is used to appropriately store the image information. Importance can be calculated.

In order to solve the above problem, according to a second aspect of the present invention, there is provided the recording control apparatus according to the first aspect, wherein the calculation unit calculates a variance value in the quantization coefficient for each of the imaging units. A variance value calculation unit such as an importance level calculation unit that calculates each value, and the calculation unit calculates a ratio of each variance value to the total sum of the calculated variance values as the importance level for each imaging unit. Configured to do.

According to the invention described in claim 2, in addition to the operation of the invention described in claim 1, a variance value in the quantization coefficient is calculated for each imaging unit, and each variance corresponding to the total sum of the calculated variance values is calculated. Since the ratio of the values is calculated as the importance for each imaging unit, the importance of the image information can be calculated more appropriately.

In order to solve the above problem, the invention according to claim 3 is the recording control apparatus according to claim 1 or 2, wherein the number of the recording medium is one, and the recording unit is configured to acquire each of the acquisition units. The image information is switched in a time-series manner according to a preset order for each of the imaging means and sequentially output to the compression means, and the compressed image information is sequentially recorded on the recording medium. .

According to the invention described in claim 3, in addition to the operation of the invention described in claim 1 or 2, when there is one recording medium, each imaging unit is time-sequentially arranged in a predetermined order. Since each image information is sequentially recorded on the recording medium by switching, it is possible to effectively prevent omission of recording of image information having high importance even when there is only one recording medium.

According to the present invention, based on the importance level of image information calculated for each imaging unit, recording is controlled so that image information with higher importance level has a longer imaging time.
In addition, since the importance is calculated for each imaging unit based on the quantization coefficient used for compression of each image information, even when the image information is compressed and recorded, the quantization coefficient is used to appropriately store the image information. Importance can be calculated.

  Therefore, it is possible to effectively prevent a recording omission of image information having a high degree of importance.

It is a block diagram etc. which show schematic structure of the security camera system which concerns on 1st Embodiment, (a) is the said block diagram, (b) is a flowchart which shows the recording process in the said security camera system. It is a conceptual diagram which illustrates the recording process of the security camera system which concerns on 1st Embodiment. It is a block diagram etc. which show schematic structure of the security camera system which concerns on 2nd Embodiment, (a) is the said block diagram, (b) is a flowchart which shows the recording process in the said security camera system. It is a block diagram etc. which show schematic structure of the security camera system which concerns on 3rd Embodiment, (a) is a conceptual diagram explaining the optical flow which concerns on 3rd Embodiment, (b) is the said block diagram. It is a flowchart etc. which show the recording process in the security camera system which concerns on 3rd Embodiment, (a) is the said flowchart, (b) is a figure which illustrates the velocity vector in the said recording process.

  Next, modes for carrying out the present invention will be described based on the drawings. The embodiment described below is an embodiment when the present invention is applied to a security camera system that sequentially obtains and records image data captured by four cameras.

(I) First Embodiment First, a first embodiment according to the present invention will be described with reference to FIGS. 1 is a block diagram showing a schematic configuration of the security camera system according to the first embodiment, and FIG. 2 is a conceptual diagram illustrating recording processing in the security camera system.

  As shown in FIG. 1A, a security camera system S1 according to the first embodiment captures each imaging range and outputs image data Sp1 to image data Sp4 which are analog signals, and a camera 1A to a camera 4A. An A / D (Analog / Digital) converter 1B to A / D converter 4B, a switching unit 5, an encoder 6 that performs an encoding process including, for example, a JPEG (Joint Photographic Experts Group) system, and a recording unit 7 A non-volatile recording medium 8 made of, for example, a hard disk or a card-type solid memory, an importance calculation unit 9, a memory 10 including a volatile area and a non-volatile area (not shown), and a switching control unit 11, respectively. Part 12. At this time, the camera 1A and the A / D converter 1B constitute the first channel CH1, and the camera 2A and the A / D converter 2B constitute the second channel CH2. The camera 3A and the A / D converter 3B constitute a third channel CH3, and the camera 4A and the A / D converter 4B constitute a fourth channel CH4. Of the above configurations, the cameras 1A to 4A correspond to an example of “imaging means” according to the present invention, and the switching unit 5 corresponds to an example of “acquisition means” and an example of “recording means” according to the present invention. To do. The importance calculation unit 9 corresponds to an example of “calculation unit”, an example of “dispersion value calculation unit”, an example of “vector detection unit”, and an example of “summation unit” according to the present invention. Further, the switching control unit 11 corresponds to an example of “control means” according to the present invention, and the encoder 6 corresponds to an example of “compression means” according to the present invention.

  In this configuration, for example, the camera 1A and the camera 4A are installed outdoors in a building that is a crime prevention target, and for example, the entrance, the entrance, and the like are used as the respective imaging ranges. On the other hand, the camera 2A and the camera 3A are installed so that, for example, any room inside the building is in the imaging range.

  Here, the image data Sp1 to image data Sp4 output from each of the cameras 1A to 4A are respectively composed of a plurality of frame images. The output timing of each frame image from each camera 1A to camera 4A is synchronized with respect to each camera 1A to camera 4A by a synchronization signal Ssy output from the synchronization unit 12. Next, the A / D converter 1B to A / D converter 4B digitize each of the image data Sp1 to image data Sp4 for each frame image to generate digital image data Sp1d to digital image data Sp4d, and to the switching unit 5 respectively. Output. At this time, the output timing of the digital image data Sp1d to digital image data Sp4d is also synchronized with respect to each digital image data by the synchronization signal Ssy.

  In the following description, when items common to the image data Sp1 to the image data Sp4 are described, they are collectively referred to as “image data Sp” as appropriate. Similarly, when the matters common to the digital image data Sp1d to Sp4d are described, these are collectively referred to as “digital image data Spd” as appropriate.

  Next, the switching unit 5 selects any of the digital image data Sp1d to Sp4d from the first channel CH1 to the fourth channel CH4 based on the switching control signal Sc generated by the switching control unit 11 based on the synchronization signal Ssy. One of them is sequentially selected and switched to it and output to the encoder 6 as switching image data Ssw. At this time, the selection / switching order in the switching unit 5 is, for example, the order of the first channel CH1, the second channel CH2, the third channel CH3, the fourth channel CH4, the first channel CH1, the second channel CH2, and so on. The

  Thus, the encoder 6 performs the above-described compression processing on the switching image data Ssw output from the switching unit 5 (in other words, any one of the digital image data Sp1d to Sp4d that are sequentially switched and output). The compressed image data Sen is generated and output to the recording unit 7. In parallel with this, the encoder 6 uses the quantization coefficient (specifically, for example, a so-called Q value) used for the compression processing applied to the switching image data Ssw as the quantization coefficient data Sq. Output to the importance calculator 9. The quantized coefficient data Sq is a quantized coefficient used for the compression processing and the like applied to each of the digital image data Sp1d to digital image data Sp4d output to the encoder 6 as the switching image data Ssw. is there. Then, the recording unit 7 performs a predetermined formatting process or the like on the output compressed image data Sen, generates recording data Sr, and records it on the recording medium 8.

  On the other hand, the importance calculation unit 9 is based on the quantization coefficient output from the switching unit 5 as the quantization coefficient data Sq, and the importance according to the first embodiment for each of the digital image data Sp1d to digital image data Sp4d. Is calculated. These calculated importance levels are output to the memory 10 as importance level data Simp. Thus, the memory 10 stores the output importance data Simp so as to be identifiable for each of the digital image data Sp1d to digital image data Sp4d, in other words, for each of the first channel CH1 to the fourth channel CH4, and necessary timing. Is output to the switching control unit 11.

  The switching control unit 11 then converts the digital image data Sp1d to the digital image data Sp4d based on the importance level data Simp for each of the first channel CH1 to the fourth channel CH4 output from the memory 10 and the synchronization signal Ssy. The switching control signal Sc for controlling the switching timing is generated and output to the switching unit 5. The importance calculation unit 9 calculates the importance for each of the first channel CH1 to the fourth channel CH4 and the switching control unit 11 generates the switching control signal Sc later using FIGS. 1B and 2. Detailed explanation.

  Through the series of processes described above, the image data from the four cameras 1A to 4A are sequentially switched in time series by the switching unit 5 and recorded on the recording medium 8 as one image stream.

  Next, the recording process according to the first embodiment in the security camera system S1 having the above-described configuration will be described more specifically with reference to FIGS. In the following description, when items common to the first channel CH1 to the fourth channel CH4 are described, these are collectively referred to as “channel CH” as appropriate.

  As shown in FIG. 1B, in the recording process according to the first embodiment, first, the switching control unit 11 initially sets the switching timing of the digital image data Sp1d to Sp4d from each channel CH. Setting is executed (step S1). In the initial setting related to step S1, for each channel CH, for example, the first channel CH1, the second channel CH2, the third channel CH3, the fourth channel CH4, the first channel CH1, and so on are switched every four frame images. These switching timings are set.

  Next, when the switching unit 5 is switched to the first first channel CH1 by the switching control unit 11 in accordance with the initial setting, the digital image data Sp1d from the first channel CH1 is stored on the basis of the synchronization signal Ssy. Each frame image is acquired via the switching unit 5 (step S2). As a result, the encoder 6 performs the above-described compression processing on the digital image data Sp1d output from the switching unit 5 as the switching image data Ssw, generates compressed image data Sen, and outputs it to the recording unit 7 (step S1). S3). In parallel with this, the encoder 6 outputs the quantization coefficient used for the compression processing or the like to the importance calculation unit 9 as quantization coefficient data Sq, and the importance calculation unit 9 acquires this (step S4). . On the other hand, the recording unit 7 performs the predetermined formatting process on the compressed image data Sen output from the encoder 6 and records it as the recording data Sr on the recording medium 8 (step S5).

  Next, the switching control unit 11 determines whether or not the timing for switching to the next second channel CH2 has come after the compression processing and the recording processing for four frame images have been completed for the digital image data Sp1d from the first channel CH1. Determination is made (step S6). If it is determined in step S6 that the digital image data Sp1d from the first channel CH1 has not been compressed for four frame images (step S6; NO), then, for example, the switching control unit 11 Then, it is determined whether or not the power switch of the entire security camera system S1 is turned off (step S11). When the power switch is turned off in the determination in step S11 (step S11; YES), the switching control unit 11, the recording unit 7 and the like end the recording process according to the first embodiment. On the other hand, if the power switch is not turned off in the determination in step S11 (step S11; NO), the digital image data Sp1d of the next frame image from the first channel CH1 is continuously acquired via the switching unit 5 (step S11). S2) The above-described compression processing, recording processing, and quantization coefficient acquisition processing are executed on the acquired digital image data Sp1d.

  On the other hand, when it is determined in step S6 that the digital image data Sp1d from the first channel CH1 has been compressed for four frame images (step S6; YES), the switching control unit 11 then The switching unit 5 is switched from the first channel CH1 to the second channel CH2 in accordance with the initial setting (step S7). Furthermore, the switching control unit 11 determines whether or not all the sample data (that is, the quantization coefficient) necessary for calculating the importance according to the first embodiment has been acquired for the channel CH (step S8). Here, at the present time when the first channel CH1 is just switched to the second channel CH2 according to the initial setting, sample data for all the channels CH cannot be acquired (step S8; NO). Therefore, for example, the switching control unit 11 returns to step S2 via step S11, and continues acquiring sampling data for all channels CH in parallel with the compression processing and the like for each channel CH.

  On the other hand, if it is determined in step S8 that acquisition of all sampling data is completed, that is, the quantization coefficients used for compression processing and the like for all channels CH can be acquired for each of four frame images (step S8; Next, the importance calculation unit 9 calculates the importance for each channel CH using the obtained quantization coefficient, and performs processing for storing the result in the memory 10 for each channel CH (step S9). .

  Here, the importance calculation processing according to step S9 will be specifically described.

The importance level according to the first embodiment is calculated by the importance level calculation unit 9 for each of the digital image data Sp1d to Sp4d based on the quantization coefficient for each channel CH described above. That is, first, the importance level calculation unit 9 calculates the variance value σ _CH of the quantization coefficient for each frame image for each of the digital image data Sp1d to Sp4d. The variance value σ _{CH in} this case is calculated by the importance calculation unit 9 for each channel CH using the following formulas (1) and (2). In Equation (1) and Equation (2), “CH” indicates the channel CH number, and “Q _{CH, t} ” indicates the quantization coefficient of one frame image (t-th frame image) in each channel CH. “N _CH ” indicates the number of frame images of the digital image data Sp1d to Sp4d used in the importance calculation processing (“4” in the case of the initial setting).

Next, the importance calculation unit 9 calculates the variance value of each channel CH with respect to the calculated sum of the variance values σ _CH for each channel CH (in the case of the first embodiment, the sum of variance values σ _CH for four channel CHs). The ratio of σ _CH is calculated by the following equation (3), and the calculated value is set as the importance V _CH of each channel CH. In the following formula (3), σ _total represents the _total sum of the variance values σ _CH .

By the above processing of the importance calculation section 9, if the security camera system S1 according to the first embodiment, the importance _{V 1} of the first channel CH1, the importance _{V 2} of the second channel CH2, the third channel CH3 severity _{V 4} severity _{V 3} and the fourth channel CH4 is calculated. As a result, the importance V _{CH in} this case has a higher (higher) value as the importance V _CH , for example, as the channel CH in which the “movement” of the imaging target in the imaging range of each camera 1 is larger. Thereafter, the importance V _CH of each channel CH calculated by the process of step S9 is temporarily stored in the memory 10 as importance data Simp, and is read out at the time of setting the switching timing, which will be described later, to set the switching timing. Used.

Next, the switching control unit 11 reads the calculated importance V _CH of each channel CH from the memory 10 as the importance data Simp, and resets the subsequent switching timing of each channel CH based on this (Step) S10). In other words, the switching control unit 11 uses the digital image data Sp1d through the digital image data in the switching unit 5 so that the imaging time at the stage where the calculated importance V _CH is larger (higher) is recorded on the recording medium 8 becomes longer. Reset the switching timing of the image data Sp4d.

  Thereafter, the switching control unit 11 returns to step S2 through the process of step S11, and switches the switching unit 5 so as to switch each channel CH in accordance with the switching timing reset by the process of the immediately preceding step S10. While controlling, the digital image data Sp1d to the digital image data Sp4d are continuously executed in the compression process and the recording process.

  Here, the recording mode in the recording medium 8 when the processing by the quantization calculation unit 9 and the switching control unit 11 in the recording processing according to the first embodiment described above is executed will be specifically described with reference to FIG. This will be described with reference to examples.

In FIG. 2, the horizontal direction is the time axis, and from the top of FIG. 2, digital image data Sp1d, digital image data Sp2d, digital image data Sp3d, and digital image data Sp4d each composed of a frame image F are shown. . 2 illustrates the recording data Sr recorded on the recording medium 8. Further, a period T _{0 to a} period T ₄ indicate periods in which the digital image data Sp1d to the digital image data Sp4d are recorded in a round. In FIG. 2, the input timing of each frame image F to the switching unit 5 is synchronized with respect to the digital image data Sp1d to Sp4d based on the synchronization signal Ssy. As a result, the input timing is recorded data. Sr is also synchronized.

In FIG. 2, a period T ₀ corresponds to a period immediately after the start of the recording process according to the first embodiment. In this period T ₀ , the switching timing of the digital image data Sp1d to digital image data Sp4d is the initial setting. Each of the four-frame images (see step S1 in FIG. 1B). Then, the digital image data Sp1d to digital image data Sp4d four frame image of the period T ₀ is outputted from each channel CH is recorded on the recording medium 8 as respective recording data Sr (FIG 1 (b) steps S5 and Referring downward black arrow in FIG. 2 period _{T 0).} Whereas in Figure 2, the period T ₀ to calculated by the importance calculation section 9 on the basis of the digital image data Sp1d to digital image data Sp4d output from each channel CH (refer to FIG. 1 (b) step S9) the importance V _CH is shown as importance V _{10 to} importance V ₄₀ for each channel CH.

In the case exemplified herein in FIG. 2, the relationship between the importance V ₁₀ to importance V ₄₀ each magnitude, it was as exemplified below.

Importance V ₁₀ = Importance V ₃₀ > Importance V ₂₀ > Importance V ₄₀
In this case, the imaging time in the digital image data Sp1d to digital image data Sp4d constituting the recording data Sr in the next period T _1,
Digital image data Sp1d imaging time = imaging time of the digital image data SP3D> imaging time of the digital image data SP2D> so that the imaging time of the digital image data Sp4d, digital image data for the period T ₁ Sp1d to digital image data Sp4d The switching timing in the switching unit 5 is reset by the switching control unit 11 (see step S10 in FIG. 1B). And the switching timing, the digital Specifically, in the period T _1, switching timing from the digital image data Sp1d to digital image data SP2D, switching timing from the digital image data SP2D into digital image data SP3D, from the digital image data SP3D respectively of switching timing to the digital image data Sp1d switching timing of the image data Sp4d, and the digital image data Sp4d in the next period T _2. These are illustrated by white arrows in FIG. When the compression processing in the encoder 6 is executed by the JPEG method, the correlation between the length of the imaging time of each image data Sp and the length of the actual recording time on the recording medium 8 is obtained through the compression processing. Will be maintained.

On the other hand, in the period T ₁ in which switching timing is re-set based on the quantization factor for the digital image data Sp1d like in the period T _0, by using the switching timing that is set back relative to the digital image data Sp1d etc. The above-described compression processing and the accompanying output processing of the quantized coefficient data Sq to the importance calculating unit 9, recording processing, importance V _CH calculating processing in the importance calculating unit 9, and the like are continuously performed ( (Refer FIG.1 (b) step S3 thru | or step S9). Note the number of frame images F severity V _CH respective digital image data Sp1d to digital image data Sp4d used for calculation processing of the respective channels CH in the period T ₁ is "7" in order from the digital image data Sp1d, "2 ”,“ 7 ”and“ 1 ”. The number of these frame images F correspond respectively to the switching timing which is re-set based on the quantization coefficient in the period T _0.

Here, the importance degree V _CH which is calculated by the importance calculating unit 9 on the basis of the respective digital image data Sp1d to digital image data Sp4d output from each channel CH period T ₁ is exemplified, for example, in FIG important It is assumed that the degree V _{11 is the} importance degree V ₄₁ . The relationship between the severity V ₁₁ to importance V ₄₁ each magnitude, and were as exemplified below.

Importance V ₁₁ > Importance V ₄₁ > Importance V ₂₁ > Importance V ₃₁
In this case, the imaging time in the digital image data Sp1d to digital image data Sp4d constituting the recording data Sr in the next period T _2,
Digital image data Sp1d imaging time of> digital image data Sp4d imaging time of> digital image data Sp2d imaging time of> so that the imaging time of the digital image data SP3D, the period T ₂ of the digital image data Sp1d to digital image data Sp4d The switching timing in the switching unit 5 is reset by the switching control unit 11 (see step S10 in FIG. 1B). And the switching timing, specifically, the period switching timing, and the digital image data Sp4d the following from the digital image data Sp1d to digital image data Sp3d period T ₂ to the respective digital image data Sp2d to digital image data Sp4d T ₃ is the switching timing to the digital image data Sp1d. Also these things illustrates the same as Figure 2, a white arrow in the case of the period T _1.

Further, even in the period T ₂ the switching timing is re-set based on the quantization factor for the digital image data Sp1d like in the period T _1, similarly to the period T ₀ and time T ₁ of the past, the set straight The above-described compression processing for the digital image data Sp1d and the like, the output processing of the quantized coefficient data Sq to the importance calculation unit 9, the recording process, and the importance V in the importance calculation unit 9 are performed using the switched timing. _CH calculation processing and the like are continuously executed (see step S3 to step S9 in FIG. 1B). Note the number of frame images F severity V _CH respective digital image data Sp1d to digital image data Sp4d used for calculation processing of the respective channels CH in the period T ₂ are, "11" in order from the digital image data Sp1d "4 ”,“ 3 ”and“ 5 ”. The number of these frame images F correspond respectively to the switching timing which is re-set based on the quantization coefficient in the period T _1.

Here, the importance degree V _CH which is calculated by the importance calculating unit 9 on the basis of the respective digital image data Sp1d to digital image data Sp4d output from each channel CH during T ₂ is illustrated, for example, in FIG important and it was degree _{V 12} to importance _{V 42.} The relationship between the severity V ₁₂ to importance V ₄₂ each magnitude, and were as exemplified below.

Importance V ₄₂ > Importance V ₂₂ > Importance V ₁₂ > Importance V ₃₂
In this case, the imaging time in the digital image data Sp1d to digital image data Sp4d constituting the recording data Sr in the next period T _3,
Digital image data Sp4d imaging time of> digital image data Sp2d imaging time of> imaging time of the digital image data Sp1d> so that the imaging time of the digital image data SP3D, digital image data Sp1d to digital image data in the period T ₃ Sp4d The switching timing in the switching unit 5 is reset by the switching control unit 11 (see step S10 in FIG. 1B). And the switching timing, specifically, the period switching timing, and the digital image data Sp4d the following from the digital image data Sp1d to digital image data Sp3d in period T ₃ to the respective digital image data Sp2d to digital image data Sp4d T ₄ is the switching timing to the digital image data Sp1d. Also these things illustrates the same as Figure 2, a white arrow and if the period T ₁ or period T _2.

Finally, in the period T ₃ in which switching timing is re-set based on the quantization factor for the digital image data Sp1d like in the period T _2, as well as the period T ₀ to time T ₂ of the past, set Using the corrected switching timing, the above-described compression processing for the digital image data Sp1d and the like, the output processing of the quantization coefficient data Sq to the importance calculation unit 9, the recording process, and the importance in the importance calculation unit 9 are performed. The _VCH calculation process and the like are continuously executed (see step S3 to step S9 in FIG. 1B). Note the number of frame images F severity V _CH respective digital image data Sp1d to digital image data Sp4d used for calculation processing of the respective channels CH in the period T ₃ is "3" in order from the digital image data Sp1d, "6 ”,“ 1 ”and“ 7 ”. The number of these frame images F correspond respectively to the switching timing which is re-set based on the quantization coefficient in the period T _2.

Here, the importance degree V _CH which is calculated by the importance calculating unit 9 on the basis of the respective output digital image data Sp1d to digital image data Sp4d from each channel CH in the period T ₃ is illustrated, for example, in FIG important and it was degree _{V 13} to importance _{V 43.} The relationship between the severity V ₁₃ to importance V ₄₃ each magnitude, and were as exemplified below.

Importance V ₁₃ > Importance V ₄₃ > Importance V ₃₃ > Importance V ₂₃
In this case, the imaging time in the digital image data Sp1d to digital image data Sp4d constituting the recording data Sr in the next period T _4,
Digital image data Sp1d imaging time of> digital image data Sp4d imaging time of> imaging time of the digital image data SP3D> so that the imaging time of the digital image data SP2D, digital image data Sp1d to digital image data in the period T ₄ Sp4d The switching timing in the switching unit 5 is reset by the switching control unit 11 (see step S10 in FIG. 1B). The A switching timing, specifically, the period switching timing, and the digital image data Sp4d the following from the digital image data Sp1d to digital image data Sp3d in period T ₄ to the respective digital image data Sp2d to digital image data Sp4d ( This is the switching timing to the digital image data Sp1d (not shown in FIG. 2). Also these things illustrates the same as Figure 2, a white arrow and if the period T ₁ to time T _3.

As described above, according to the recording process in the security camera system S1 according to the first embodiment, each camera 1A-camera 4A (i.e. per channel CH) more importance V _CH higher image data Sp calculated in, since the switching unit 5 so that the imaging time of the recording data Sr is increased is controlled by the switching control unit 11, it is possible to prevent the recording leakage severity V _CH higher image data Sp effectively.

Further, when there is only one recording medium 8, since each image data Sp is sequentially recorded in the recording medium 8 by switching in time series for each channel CH in a predetermined order, there is only one recording medium 8. However, it is possible to effectively prevent the recording omission of the image data Sp having a high importance level V _CH .

Further, since the importance V _CH is calculated for each channel CH based on the quantization coefficient used for compression of each image data Sp, even when the image data Sp is compressed and recorded, the quantization coefficient is used appropriately. The importance V _CH of the image data Sp can be calculated.

Furthermore, the variance sigma _CH in the quantization coefficient is calculated for each channel CH, the proportion of the respective dispersion values sigma _CH to the sum sigma _total of the calculated variance value sigma _CH as severity V _CH of each channel CH Since it is calculated, the importance V _CH of the image data Sp can be calculated more appropriately.

  In the first embodiment described above, the case where the JPEG method is used as the compression method in the encoder 6 has been described. However, in addition to this, compression in which different compression parameters are used corresponding to the movement of the imaging object in the frame image F. If it is a system, the present invention can be applied when another compression system is used.

(II) Second Embodiment Next, a second embodiment which is another embodiment of the present invention will be described with reference to FIG. FIG. 3 is a block diagram showing a schematic configuration of the security camera system according to the second embodiment. In FIG. 3A, the same components as those in the security camera system S1 according to the first embodiment described with reference to FIG. . Further, in FIG. 3B, the same processing steps as the recording processing in the security camera system S1 according to the first embodiment described with reference to FIG. Omitted.

When the security camera system according to the second embodiment described below and the security camera system S1 according to the first embodiment described above are compared, the calculation method of the importance V _CH for each image data Sp is different. Yes. That the security camera system S1 according to the first embodiment, is calculated on the basis of the quantization coefficients in the compression process performed importance V _CH to the image data Sp. The security camera system according to the second embodiment described below with respect to this, the importance V _CH, calculated based on the difference between the frame image F of the image data Sp from each channel CH.

As shown in FIG. 3A, the security camera system S2 according to the second embodiment is similar to the security camera system S1 according to the first embodiment in the first channel CH1 to the fourth channel CH4, the switching unit 5, and the encoder. 6. In addition to the recording unit 7, the recording medium 8, the memory 10, the switching control unit 11, and the synchronization unit 12, an importance calculation unit 20 is used instead of the importance calculation unit 9 in the security camera system S1 according to the first embodiment. I have. Further, the switching image data Ssw output from the switching unit 5 is directly output to the importance calculation unit 20 in parallel with the output to the encoder 6. Thereby, the importance calculation unit 20 of the security camera system S2 according to the second embodiment calculates the difference between the frame images F in any one of the digital image data Sp1d to digital image data Sp4d input as the switching image data Ssw. Based on this, the importance level V _CH according to the second embodiment is calculated, and importance level data Simp indicating it is generated and output to the memory 10.

  Next, the recording process according to the second embodiment in the security camera system S2 having the above-described configuration will be described more specifically with reference to FIG.

  As shown in FIG. 3B, in the recording process according to the second embodiment, first, the processes of steps S1 to S3 similar to the recording process according to the first embodiment are executed.

  In parallel with these, the switching unit 5 outputs the switching image data Ssw to the importance calculation unit 20. As a result, the importance calculation unit 20 detects a difference between the frame images F in any of the digital image data Sp1d to Sp4d input as the switching image data Ssw (step S20). More specifically, the importance calculation unit 20 compares, for example, luminances of corresponding pixels in two consecutive frame images F in one digital image data Spd, and detects the difference for each pixel. The entire frame image F is performed. Next, the importance calculation unit 20 acquires the number of pixels for which the detected difference is equal to or greater than a preset threshold difference for each frame image F, and for example, this is not illustrated in the importance calculation unit 20 It is temporarily stored in the memory (step S21). In the following description, the number of pixels in one frame image F in which the detected difference is equal to or greater than the threshold difference is simply referred to as “the number of pixels in the difference area”. The threshold difference may be set in advance experimentally or experimentally. Alternatively, a so-called histogram of the frame image F may be detected / accumulated and used, for example, using a so-called discriminant analysis method, or the average value or median value of the histogram may be set as the threshold difference. Good. In the case of these two methods, the threshold difference changes for each frame image F. After that, the same processes of step S5 to step S8 and step S11 as the recording process according to the first embodiment are executed.

Next, in the determination of step S8, when acquisition of all sampling data is completed, that is, the number of pixels in the difference area in the four frame images F as the initial setting can be acquired for all channels CH (step S8). S8; YES), the importance level calculation unit 20 calculates the importance level V _CH for each channel CH using the acquired number of pixels in the difference area, and stores the result in the memory 10 for each channel CH. Is performed (step S22).

Here, the calculation process of the importance V _{CH according} to step S22 will be specifically described.

The importance V _{CH according} to the second embodiment is determined by the importance calculation unit 20 for each of the digital image data Sp1d to Sp4d based on the number of pixels in the difference area for each frame image F of each channel CH described above. Calculated. That is, first, the importance calculation unit 20 calculates the total P _CH for each channel CH of the number of pixels in the difference area for each frame image F for each of the digital image data Sp1d to Sp4d. The total P _{CH in} this case is calculated for each channel CH using the following equation (4). In equation (4), “CH” indicates the channel CH number, “P _t ” indicates the number of pixels in the difference area of one frame image F (t-th frame image F) in each channel CH, and “ “P _CH ” indicates the sum of the number of pixels in the difference area in each channel CH (sum of the number of pixels in the difference area for each frame image F), and “N _CH ” indicates the digital image data Sp1d to Sp1d used for the importance calculation processing. The number of frame images F of the digital image data Sp4d (“4” in the case of the initial setting) is shown.

Then the importance calculation section 20, to the sum P _total sum P _CH of each channel CH that have been calculated (i.e. in the case of the second embodiment, the sum P _total of the four channels of the sum P _CH of each channel CH) The ratio of the total P _CH of each channel CH is calculated by the following equation (5), and the calculated value is set as the importance V _CH of each channel CH.

By the above processing of the importance calculation section 20, even if the security camera system S2, according to the second embodiment, the importance of the first channel CH1 V ₁ to fourth channel CH4 importance V ₄ is calculated. Similarly to the case of the first embodiment, the importance V _{CH in} this case is also higher (higher) as the importance V _CH, for example, as the channel CH in which the “movement” of the imaging object within the imaging range of each camera 1 is larger. Value. Thereafter, the importance level V _CH of each channel CH calculated by the processing of step S22 is temporarily stored in the memory 10 as importance level data Simp, and is read when the switching timing is set as step S10 according to the second embodiment. And used for setting the switching timing.

That is, the switching control unit 11 according to the second embodiment reads the calculated importance V _CH of each channel CH from the memory 10 as the importance data Simp, and based on this, the switching timing of each subsequent channel CH is read out. The setting is reset (step S10). Specifically, similarly to the recording process according to the first embodiment, the switching control unit 11 takes an imaging time at a stage where the calculated channel V having a larger (higher) importance V _CH is recorded on the recording medium 8. Is set again so that the switching timing of the digital image data Sp1d to Sp4d in the switching unit 5 is set.

Thereafter, as in the case of the recording process according to the first embodiment, the importance V _{CH according} to the second embodiment is determined for the continuous period T ₀ , period T ₁ , period T ₂ ,... (See FIG. 2). Calculation and setting of the switching timing of the digital image data Sp1d to Sp4d based on the calculation are repeated.

As described above, according to the recording process in the security camera system S2 according to the second embodiment, similarly to the recording process according to the first embodiment, the image data having a high importance level V _CH calculated for each channel CH. As Sp is controlled so that the imaging time in the recording data Sr becomes longer, and each image data Sp is sequentially recorded on the recording medium 8 by switching in time sequence for each channel CH in a predetermined order. It is possible to effectively prevent recording omission of image data Sp having a high degree V _CH .

In addition, according to the recording process in the security camera system S2, according to the second embodiment, based on the difference for each pixel between the frame images F constituting the image data Sp importance degrees V _CH per channel CH Therefore, the importance V _CH of the image data Sp can be calculated appropriately using the difference between the frame images F in the image data Sp.

(III) Third Embodiment Finally, a third embodiment, which is still another embodiment according to the present invention, will be described with reference to FIGS. FIG. 4 is a block diagram showing a schematic configuration of the security camera system according to the third embodiment, and FIG. 5 is a flowchart showing recording processing in the security camera system. In FIG. 4A, the same components as those in the security camera system S1 according to the first embodiment described with reference to FIG. . Further, in FIG. 5A, the same step number is assigned to the same process as the recording process in the security camera system S1 according to the first embodiment described with reference to FIG. Omitted.

When the security camera system according to the third embodiment described below is compared with the security camera system S1 according to the first embodiment described above, the above-mentioned important information about each image data Sp is the same as in the second embodiment. The calculation method of degree V _CH is different. That is, in the security camera system according to the third embodiment described below, the importance V _CH for each image data Sp corresponds to the movement of the imaging target for each frame image F in the image data Sp from each channel CH. It calculates based on the vector to do. In the case of the third embodiment described below, the vector is calculated by a so-called optical flow method.

Here, the optical flow method according to the third embodiment is an analysis of “movement” of an imaging target in a pixel from luminance data indicating, for example, luminance of each pixel in the frame image F. This is a method for calculating a vector (for example, a velocity vector indicating the motion). More specifically, in the optical flow method, a vector sum of pixel vectors (having components in the x direction and the y direction) in a predetermined range in the frame image F is calculated for the predetermined range, Is a vector as the entire predetermined range. Since the “vector” is calculated in this case, not only the “amount” as the motion but also the “direction” can be considered. That is, for example, in each of the twelve pixels PX _{11 to} PX ₁₅ , the pixels PX _{21 to} PX _25, and the pixels PX _{31 to} PX ₃₅ constituting a certain frame image F illustrated in FIG. Is detected as indicated by an open solid arrow. If the optical flow method is used in this case, for example, a vector of a region including the pixel PX ₁₂ , the pixel PX ₁₃ , the pixel PX ₂₂ , the pixel PX ₂₃ , the pixel PX _32, and the pixel PX ₃₃ near the center of the frame pixel F is This corresponds to the downward arrow indicated by the alternate long and short dash line in 4 (a). On the other hand, for example, the vector for the entire frame pixel F corresponds to a rightward arrow indicated by a broken line in FIG. If such an optical flow method is used, the importance V _CH can be calculated in consideration of the direction in which the imaging target is moving in the upper, lower, left and right directions of the entire frame image F.

  Next, the security camera system according to the third embodiment will be specifically described.

As shown in FIG. 4B, the security camera system S3 according to the third embodiment is similar to the security camera system S1 according to the first embodiment in the first channel CH1 to the fourth channel CH4, the switching unit 5, and the encoder. 6, in addition to the recording unit 7, the recording medium 8, the memory 10, the switching control unit 11, and the synchronization unit 12, an importance calculation unit 30 is used instead of the importance calculation unit 9 in the security camera system S1 according to the first embodiment. I have. Further, the switching image data Ssw output from the switching unit 5 is directly output to the importance calculating unit 30 in parallel with the output to the encoder 6 as in the case of the second embodiment. Thereby, the importance calculation unit 30 of the security camera system S3 according to the third embodiment, based on the frame image F in one of the digital image data Sp1d to digital image data Sp4d input as the switching image data Ssw, using an optical flow method calculates the vector in the frame image F, and calculates the importance V _CH of the third embodiment on the basis thereof. The importance level data Simp indicating the importance level V _CH is output from the importance level calculation unit 30 and stored in the memory 10.

  Next, the recording process according to the third embodiment in the security camera system S3 having the above-described configuration will be described more specifically with reference to FIG.

  As shown in FIG. 5A, in the recording process according to the third embodiment, first, the process of step S1 similar to the recording process according to the first embodiment is executed.

  Next, in the importance calculation unit 30, a direction that is considered to be important for the movement of the imaging target within the imaging range of each channel CH (in other words, each camera 1A to camera 4A) (hereinafter, this direction is referred to as “important direction”). Is set) (step S30). This important direction may be set in advance for each channel CH by the user of the security camera system S3 and stored in the importance calculation unit 30, or the importance calculation unit 30 based on the past history or the like. May be automatically set for each channel CH.

  When the important direction for each channel CH according to the third embodiment is set, the processes of step S2 and step S3 similar to the recording process according to the first embodiment are executed next.

In parallel with these, the switching unit 5 outputs the switching image data Ssw to the importance calculation unit 30. As a result, the importance calculation unit 30 calculates the vector for each frame image F in the digital image data Sp1d to Sp4d input as the switching image data Ssw (step S31). More specifically, the importance calculation unit 30 calculates a vector (v _x , v _y ) for one frame image F in one digital image data Spd by the above-described optical flow method, and uses this as an importance calculation unit, for example. The information is temporarily stored in a memory 30 (not shown). These vectors are, for example, velocity vectors. Next, the importance calculation unit 30 adds the calculated vector for each frame image F by the amount of the frame image F in one continuous channel CH, and adds the sum vector (OF _{x, CH} , OF _y for each channel CH). _{, CH} ) are calculated and temporarily stored in a memory (not shown) (step S32). Here, the sum vector (OF _{x, CH} , OF _{y, CH} ) is calculated by the importance calculation unit 30 for each channel CH using the following equations (6) and (7). In Equations (6) and (7), “CH” indicates the channel CH number, and “v _{x, t} ” is a vector of one frame image F (t-th frame image F) in each channel CH. It is a component in the x direction, and “v _{y, t} ” is a component in the y direction of the vector of the one frame image F. Further, “N _CH ” indicates the number of frame images F of the digital image data Sp1d to Sp4d used for importance calculation processing (“4” in the case of the initial setting).

When the sum vector _{(OF x, CH, OF y} , CH) can be calculated for each channel CH, then the importance calculation section 30, the sum vector for each channel CH calculated (OF _{x, CH,} OF _{y, CH 2} ), the component vector in the important direction set by the processing of step S30 for the channel CH is calculated (step S33). And that is important direction in a channel CH is a direction indicated by a vector V _i illustrated in FIG. 5 (b), the sum vector V _M calculated for that channel CH were vector exemplified in FIG. 5 (b) To do. The magnitude of the sum vector V _M in this case, a size shown in the following equation (8).

In this case the importance calculation section 30, as the process of step S33, calculates the component vector _{V Mi} illustrated in FIG. 5 (b) as the vector _{V i-direction} component of the sum vector _{V M.} The calculated component vector V _Mi is temporarily stored in the memory (not shown) so as to be identifiable for each channel CH. After that, the same processes of step S5 to step S8 and step S11 as the recording process according to the first embodiment are executed.

Next, in the determination in step S8, when acquisition of all sampling data is completed, that is, the above component vectors V _Mi in the four frame images F as the initial settings can be calculated for all channels CH (step S8). S8; YES), the importance level calculation unit 30 calculates the importance level V _CH for each channel CH in the order of the calculated component vector V _Mi and stores the result in the memory 10 for each channel CH. Is performed (step S34). More specifically the importance calculation section 30 calculates the importance V _CH as severity V _CH higher channel CH larger component vector V _Mi is increased, the result as important data Simp per channel CH Store in the memory 10. The importance V _{CH in} this case is also the importance V _CH as the channel CH in which the “movement” of the imaging target in the imaging range of each camera 1 is larger, for example, as in the first embodiment and the second embodiment. _CH is a large (high) value. Thereafter, the stored importance V _CH of each channel CH is read out at the time of setting the switching timing as step S10 according to the third embodiment, and is used for setting the switching timing.

That is, the switching control unit 11 according to the third embodiment reads the calculated importance V _CH of each channel CH from the memory 10 as importance data Simp, and based on this, the switching timing of each subsequent channel CH is read out. The setting is reset (step S10). Specifically, similarly to the recording process according to each of the first embodiment and the second embodiment, the switching control unit 11 records a channel CH having a higher (higher) calculated importance level V _{CH on the} recording medium 8. The switching timing of the digital image data Sp1d to digital image data Sp4d in the switching unit 5 is reset so that the imaging time at the stage becomes longer.

Thereafter, as in the case of the recording process according to each of the first and second embodiments, the continuous period T ₀ , the period T ₁ , the period T ₂ ,. severity V _CH calculates the digital image data Sp1d to set the switching timing of the digital image data Sp4d based thereon according is repeated.

As described above, according to the recording process in the security camera system S3 according to the third embodiment, the importance calculated for each channel CH is the same as the recording process according to each of the first embodiment and the second embodiment. The image data Sp with higher V _CH is controlled so that the imaging time in the recording data Sr becomes longer, and the image data Sp is sequentially transferred to the recording medium 8 by switching in time series for each channel CH in a predetermined order. since the recording, it is possible to prevent the recording leakage severity V _CH higher image data Sp effectively.

In addition to this, according to the recording process in the security camera system S3 according to the third embodiment, the importance level V _CH is calculated for each channel CH based on the sum vector (OF _{x, CH} , OF _{y, CH} ). The importance V _CH of the image data Sp can be calculated appropriately using the sum vector (OF _{x, CH} , OF _{y, CH} ).

Further, based on the sum vector (OF _{x, CH} , OF _{y, CH} ) and the vector V _i in the important direction for each channel CH, the component (component vector) in the important direction of the sum vector (OF _{x, CH} , OF _{y, CH} ). since calculating the importance degree V _CH for each channel CH based on the magnitude of V _Mi), it is possible to calculate the importance of V _CH of better image data Sp.

  In each of the embodiments described above, the case where the present invention is applied to a security camera system has been described. However, in addition to this, a plurality of cameras are provided, and image data from each camera is obtained from the number of cameras. The present invention can also be applied when recording on a small number of recording media.

  In addition, a program corresponding to the flowchart described in FIG. 1B, FIG. 3B, or FIG. 4B is recorded on a recording medium such as an optical disk or acquired via a network such as the Internet. It is also possible to use the computer as the switching control unit 11 according to each embodiment by recording the program and reading and executing the program with a general-purpose computer such as a microcomputer.

  As described above, the present invention can be used in the field of camera systems, and particularly in the field of camera systems that record image data captured by a plurality of cameras on a smaller number of recording media than the number of cameras. When applied to, particularly remarkable effects can be obtained.

1A, 2A, 3A, 4A Camera 1B, 2B, 3B, 4B A / D converter 5 Switching unit 6 Encoder 7 Recording unit 8 Recording medium 9, 20, 30 Importance calculation unit 10 Memory 11 Switching control unit 12 Synchronization unit F Frame Image S1, S2, S3 Security camera system CH1 1st channel CH2 2nd channel CH3 3rd channel CH4 4th channel PX ₁₁ , PX ₁₂ , PX ₁₃ , PX ₁₄ , PX ₁₅ , PX ₂₁ , PX ₂₂ , PX ₂₃ , PX ₂₄ , PX ₂₅ , PX ₃₁ , PX ₃₂ , PX ₃₃ , PX ₃₄ , PX ₃₅ pixels

Claims (5)

Acquisition means for acquiring image information corresponding to images respectively captured by a plurality of imaging means from the imaging means;
Compression means for compressing each of the image information;
Recording means for switching each acquired image information and sequentially outputting the compressed image information to the compression means, and sequentially recording the compressed image information on a smaller number of recording media than the number of the imaging means;
Calculation means for calculating the importance of each acquired image information for each of the imaging means based on the quantization coefficient used for compression of each of the image information ;
Based on the calculated importance, the control means for controlling the recording means so that the image information having a higher importance has a longer imaging time in the image information recorded on the recording medium;
A recording control apparatus comprising: The recording control apparatus according to claim 1,
The calculation means includes a variance value calculation means for calculating a variance value in the quantization coefficient for each imaging means for each imaging means,
The recording control apparatus , wherein the calculation unit calculates a ratio of each variance value to a total sum of the calculated variance values as the importance for each imaging unit . In the recording control apparatus according to claim 1 or 2,
The recording medium is one,
The recording means switches the acquired image information in a time-series manner according to a preset order for the imaging means and sequentially outputs the compressed image information to the recording medium. A recording control apparatus for sequentially recording . A computer included in a recording control apparatus including an acquisition unit that acquires image information corresponding to images captured by a plurality of imaging units from each of the imaging units,
Compression means for compressing each image information;
Recording means for switching each acquired image information and sequentially outputting the information to the computer functioning as the compression means, and sequentially recording the compressed image information on a number of recording media smaller than the number of the imaging means,
Calculating means for calculating the importance of each acquired image information for each imaging means based on a quantization coefficient used for compression of each of the image information; and
Control means for controlling the recording means so that the image information with higher importance is based on the calculated importance, and the imaging time in the image information recorded on the recording medium is longer.
A program for recording control , which is made to function as: In a recording control method executed in a recording control apparatus including an acquisition unit that acquires image information corresponding to images captured by a plurality of imaging units from each of the imaging units,
A compression step of compressing each of the image information;
A recording step of switching each acquired image information and sequentially outputting the compressed image information to the compression step, and sequentially recording the compressed image information on a number of recording media smaller than the number of the imaging means;
A calculation step of calculating the importance of each acquired image information for each imaging unit based on a quantization coefficient used for compression of each of the image information;
Based on the calculated importance, a control step for controlling recording on the recording medium such that the higher the importance of the image information, the longer the imaging time in the image information recorded on the recording medium;
Including a recording control method .