JP2010278614A - Image monitoring/recording device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image monitoring/recording device that achieves excellent imaging and recording without being affected by an imaging environment such as backlight. <P>SOLUTION: The image monitoring/recording device 1 includes: a digital image data generating part 10 that has an exposure control means and divides image signals into odd-numbered frames and even-numbered frames so as to generate first/second digital image data from the odd-numbered and even-numbered frames; a recording means 20 for recording each of the first/second digital image data; a motion detecting means 30 that detects a moving object from either one of the first/second digital image data, and detects the position and size of the moving object when detected; and an exposure control part 40 that divides one digital image data into a plurality of blocks so as to calculate an average luminance value for each block, calculates luminance information of each block from the average luminance value, and sets exposure conditions of the exposure control means in imaging the odd-numbered frames and those in imaging the even-numbered frames, on the basis of the luminance information and the detection result. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an image monitoring and recording apparatus that records an image obtained by imaging a monitoring area, and more particularly to an image monitoring and recording apparatus that records an image obtained by imaging a change in state when a change in the state of the monitoring area is detected.

  2. Description of the Related Art Conventionally, there is known an image monitoring and recording apparatus that compresses a captured image at a preset compression rate and records the compressed image on a recording unit. Further, in such an image monitoring and recording apparatus, for the purpose of recording for a long time, the state of the captured image is detected, and the captured image is compressed only when it is determined that the state change is not a steady state. An alarm recording technique for recording has already been disclosed (for example, see Patent Document 1 below).

  In the image recording apparatus described in Patent Document 1, when a motion of a person is detected from a captured image, the captured image is recorded on a hard disk for a predetermined time determined according to the degree of abnormality of the motion of the person. In this way, the recorded image is recorded only when the movement of the person is detected, and the recording time is adjusted according to the degree of abnormality, thereby eliminating unnecessary image recording while ensuring the necessary time. And the utilization efficiency of the recording medium can be greatly increased.

  In addition, in the image recording apparatus described in Patent Document 1, when an abnormality in the movement of a person in the monitoring area is detected, the person in the monitoring area is controlled by performing pan / tilt / zoom by controlling the camera device. Even if the positions of are different, the display of the person image on the display screen is enlarged at substantially the same position. In this way, by controlling the image to be captured, it is possible to easily confirm the person from whom an abnormality has been detected.

JP 2007-124526 A

  However, the image recording apparatus as described above is intended to improve the utilization efficiency of the recording medium and to control the position and size of the person image displayed on the display screen. The exposure of the image to be picked up was not controlled according to the above.

  Therefore, in the above-described image recording apparatus, when a moving body located in an environment such as backlight is photographed, the moving body is recorded as a black subject, and the intruder's face and clothes required for the monitoring recording apparatus are accurately recorded. There was a problem that could not be recorded.

  In addition, when multiple moving bodies are detected in areas with different shooting environments, such as areas with backlight and areas without backlight, images with optimum exposure for the multiple moving bodies are recorded. There was a problem that could not.

  Accordingly, the present invention has been made in view of the above problems, and an object thereof is to obtain an image monitoring and recording apparatus that enables good shooting and recording without being affected by a shooting environment such as backlight.

  The image monitoring and recording apparatus according to the embodiment of the present invention has an exposure control unit that controls exposure at the time of shooting, divides an image signal shot by controlling exposure into odd frames and even frames, and starts from the odd frames. A digital image data generation unit that generates second digital image data from even-numbered frames of the first digital image data; a recording unit that records the first digital image data and the second digital image data; The presence or absence of a moving body is detected from one digital image data of the first digital image data and the second digital image data, and when the moving body is detected, the position and size of the moving body are detected. The motion detection means and the one digital image data are divided into a plurality of blocks to calculate an average luminance value for each block, and from the average luminance value Exposure for calculating brightness information for each lock, and setting exposure conditions of the exposure control means when photographing the odd frame and the even frame based on the brightness information for each block and the detection result of the detection means A control unit.

  According to the image monitoring and recording apparatus of the present invention, even if a plurality of moving bodies are located in environments with different exposure conditions, it is possible to properly expose each moving body. Accurate shooting of faces and clothes is possible. Also, only when a moving object whose proper exposure condition is different from that during normal photographing is detected, a small-size image obtained by photographing the moving object under a special environment is recorded redundantly for a predetermined time, so that the recording capacity is increased redundantly. Therefore, it is possible to store an accurate photographed image such as an intruder's face and clothes required for the image monitoring and recording apparatus.

It is the figure which showed schematically the structure of the image monitoring recording device which concerns on embodiment of this invention. It is a figure explaining the state of the captured image when normal exposure control is performed. It is the flowchart which showed the process which the image monitoring recording device which concerns on embodiment of this invention produces | generates a 1st image data stream and a 2nd image data stream. It is the figure which showed a mode that the image monitoring recording device which concerns on embodiment of this invention produces | generates the 1st image data stream and the 2nd image data stream. It is the flowchart which showed the process in which the image monitoring recording device which concerns on embodiment of this invention detects a moving body. It is the flowchart which showed the exposure process which the image monitoring recording device which concerns on embodiment of this invention performs with respect to a to-be-photographed object. 5 is a flowchart showing operations until the image monitoring recording apparatus according to the embodiment of the present invention records the first image data stream and the second image data stream in the image recording unit. It is the figure which showed a mode that the image monitoring recording device which concerns on embodiment of this invention compresses the 1st data stream and the 2nd data stream.

<1. Configuration of image monitoring and recording apparatus>
FIG. 1 is a diagram schematically showing a configuration of an image monitoring and recording apparatus 1 according to an embodiment of the present invention. As shown in FIG. 1, the image monitoring and recording apparatus 1 includes a digital image data generating unit 10 that acquires digital image data from an image in a monitoring area, a recording unit 20 that compresses and records digital image data, and a digital image. Conditions for the motion detection processing unit 30 that detects whether or not a moving object is present in the monitoring area from the data, the exposure control unit 40 that controls the exposure at the time of shooting, and the processing units of the image monitoring recording apparatus 1 And a main control unit 50 such as a CPU for performing setting, processing command transmission, less pump processing and the like.

  The digital image data generation unit 10 includes a lens 11 that forms a subject image in a monitoring area, an imaging unit 12 that photoelectrically converts an optical image into an electrical signal using a CCD or CMOS sensor, and the like. AGC (Automatic Gain Control) circuit 13 that automatically controls the gain (sensitivity) so as to obtain an appropriate exposure amount, AD converter 14 that converts the analog signal output from AGC circuit 13 into a digital signal, and AD converter 14 And a camera image processing unit 15 that generates digital image data in the luminance (Y) and color difference (Cb, Cr) format based on the video signal generated in step (b).

  The recording unit 20 includes an image compression / decompression unit 21 that compresses the digital image data output from the camera image processing unit 15 using JPEG or MPEG4, and an image recording unit 22 that records the compressed digital image data.

  The exposure control unit 40 divides the digital luminance data for one screen generated by the camera image processing unit 15 into a plurality of blocks, and calculates a luminance average value for each of the divided blocks. An integration processing unit 42 for integrating the luminance average value of each block calculated by the block luminance average value calculating unit 41 in the time axis direction in the frame period, and the average luminance value of each block integrated in the time axis direction and the current An AE (Auto Exposure) control unit 43 that controls the exposure at the time of imaging based on the comparison result of the average luminance value of each block and the result of the motion detection processing unit 30 is provided. As will be described later, such an exposure control unit 40 is employed to obtain a good shot image even under a shooting environment such as backlight. The exposure control may be controlled by an electronic shutter that the image sensor has as a function, a mechanical shutter that is mechanically controlled, or other methods.

<2. Operation of Pixel Monitoring and Recording Device>
Next, the operation of the pixel monitoring recording apparatus will be described.

<2-1. Operation to perform normal exposure processing>
First, with reference to FIG. 1, an operation for performing a normal exposure process (for example, a process in which the average luminance of the entire screen becomes about 50% gray) will be described.

  First, the monitoring recording apparatus 1 forms an image of a subject in the monitoring area with the lens 11 and photoelectrically converts the optical image into an image signal by the imaging unit 12. Here, the imaging unit 12 is configured by arraying semiconductor sensors such as CCD and CMOS in units of pixels. Due to the recent progress in semiconductor densification technology and the demand for high-definition images in image monitoring systems, for example, a megapixel semiconductor sensor such as 1280 × 960 pixels is used. Further, when photoelectric conversion is performed by the imaging unit 12, for example, an 8-bit 256-gradation image from the moonlight of 1 lux (hereinafter referred to as “lx”) or less to the brightness of the clear sky reaching 10000 lx or more. In order to convert it into data, exposure control is performed by adjusting the amount of light with a mechanical shutter attached in front of the imaging unit 12, an electronic shutter of the imaging unit 12, or the like. Further, the AGC circuit 13 performs gain adjustment for the amount that cannot be absorbed only by the shutter control. Hereinafter, such a mechanical shutter, electronic shutter, AGC circuit 13 and the like are also referred to as exposure control means.

  Further, although not shown, a circuit for performing processing such as γ correction may be provided, and in order to adjust the output from the AGC circuit 13 to a screen that is easier to view in consideration of the characteristics of the display device, Processing such as nonlinear γ correction is performed in the signal state.

  Next, the analog signal output from the AGC circuit 13 is converted into a digital signal by the AD converter 14 and converted into digital image data by the camera image processing unit 15. Note that the quantization of the AD converter 14 is not necessarily 8 bits. For example, the AD converter 14 converts the signal to 10 to 12 bits and performs non-linear processing in the camera image processing unit 15 in the subsequent stage to obtain luminance. When generating data of (Y) and color difference (Cb, Cr) signals, they may be converted into final 8-bit data.

  Digital image data generated by performing such normal backlight correction is greatly affected by the installation environment (imaging environment) of the image monitoring and recording apparatus 1. Hereinafter, with reference to FIG. 2, a captured image when the above-described normal exposure control is performed will be described.

  FIG. 2 is a diagram illustrating the state of a captured image when normal exposure control is performed. FIG. 2A is a diagram illustrating a state in which the daytime monitoring area is imaged by the image monitoring recording apparatus 1 installed indoors. FIG. 2B is a diagram illustrating a captured image obtained by capturing the monitoring area illustrated in FIG. As shown in FIG. 2, when the image monitoring and recording apparatus 1 installed indoors is photographed toward the glass door 2, the light of the sun 3 is incident in the daytime, so the vicinity of the glass door 2 is locally bright. Become.

  In such a shooting environment, when there is a person 4 entering the room indoors from the glass door 2 and a person 5 standing indoors away from the glass door 2, a normal camera image is shown in FIG. The captured image is as shown in FIG. That is, due to backlight, the face and appearance of the person 4 entering the room through the glass door 2 appear black, and the face and clothes cannot be accurately projected. On the other hand, the person 5 standing at a place away from the glass door is not affected by the backlight, and thus can accurately project his face and clothes.

  Such a captured image is obtained by performing exposure adjustment by setting a luminance target so that the average luminance of the entire screen is about 50% gray in the normal camera exposure control as described above. That is, in FIG. 2, the exposure through the glass door 2 is extremely bright and the exposure is narrowed down even though the front surface (face) of the moving body 4 in a position that blocks sunlight is shaded and dark. It is necessary to shoot with the exposure narrowed down.

  On the other hand, since the person 5 standing away from the glass door 2 is not affected by backlight, it can be accurately projected by performing normal exposure control. That is, if the exposure is adjusted so that the person 4 entering from the glass door 2 is accurately projected, the person 5 standing away from the glass door 2 may not be accurately captured. As described above, in the shooting area where the subject is located in an environment where the optimal exposure conditions are different, if the exposure is adjusted to one person, the other person may not be accurately captured.

  Therefore, in the present embodiment, optimal exposure processing is performed on subjects located in environments with different optimal exposure conditions to generate different image data streams. That is, under the shooting environment shown in FIG. 2, first, for a person 5 standing away from the glass door 2, an image taken under normal exposure conditions is generated as a first image data stream. . For the person 4 entering through the glass door, an image obtained by adjusting the exposure by setting the person 4 entering through the door as a luminance target and generating a second image data stream is generated.

<2-2. Operation for generating first and second image data streams>
Next, an operation for generating the first image data stream and the second image data stream will be described.

  FIG. 3 is a flowchart showing a process for generating the first image data stream and the second image data stream. FIG. 4 is a diagram showing how the first image data stream and the second image data stream are generated.

  First, the imaging unit 12 captures images in the monitoring area at predetermined time intervals. Here, since a normal camera generally generates an image at 30 frames per second, the following description will be made assuming that shooting is performed at 30 frames per second in the present embodiment. However, the frame rate is not limited to this, and other frame rates may be used. Also, surveillance cameras (image recording devices) such as banks that monitor intruders are required to record for a long time as much as possible within the limited recording capacity. It is desirable to record while keeping the frame rate as low as possible, and 15 frames per second is sufficient.

  Next, the AD converter 14 acquires a frame image and converts an analog signal into a digital signal D1. Then, the camera image processing unit 15 generates digital image data D2 in the luminance (Y) and color difference (Cb, Cr) format from the digital signal D1 (S11).

  Next, the camera image processing unit 15 distributes the digital image data D2 into odd frame data D2a and even frame data D2b (FIG. 4A). Then, the camera image processing unit 15 generates a first image data stream D3a that is composed of luminance and color difference data and is used for display and normal recording from the odd-numbered frame data D2a (S12, FIG. 4B).

  On the other hand, the camera processing unit 15 generates a second image data stream D3b composed of luminance and chrominance data from the even-numbered frame data D2b for a predetermined time only when it is determined to be “present” in the backlight moving object detection described later. Only generate. Note that the second image data stream D3b is not all the 1280 × 960 pixels described above, but has a size obtained by cutting out the position and size of the moving object in the captured image obtained by the motion detection processing unit 30 described later. Use image data. On the other hand, if it is determined as “no” in the backlight moving body detection determination, the image data size is set to 0 and the second image data stream D3b is generated (S13, FIG. 4B).

  Through the above processing, the first image data stream D3a and the second image data stream D3b are generated from the image obtained by capturing the monitoring area.

<2-3. Operation to detect moving objects>
Next, an operation for detecting a moving body used as information when determining whether or not to detect backlit moving body will be described. In the present embodiment, a background difference method is used in which a moving object is detected based on a difference in image data with respect to a background image serving as reference image data.

  FIG. 5 is a flowchart showing a process for detecting a moving object. First, the motion detection processing unit 30 receives the first image data stream D3a that is the output of the camera processing unit 15, and generates RGB image data D4 obtained by RGB conversion of this data (S21). Then, background image data D5 is generated by integrating the RGB image data D4 in the time axis direction (S22). Then, the background image data D5 is stored in a background image data storage area (not shown) of the motion detection processing unit 30 (S23).

  Next, the motion detection processing unit 30 sequentially receives the first image data stream D3a, and generates RGB image data D4 obtained by performing RGB conversion on this data (S24). Then, the RGB image data D4 and the background image data D5 are compared, and based on the comparison result, it is determined whether or not a state change has occurred in the monitoring area. Specifically, each pixel is compared, and it is determined whether or not a state change has occurred in the monitoring area based on whether or not there is a change greater than a predetermined value. When it is determined that a state change has occurred, a portion where the change is greater than or equal to a predetermined value is enclosed by a square, and the position and size of the moving body are extracted.

  For example, when it is determined that no state change has occurred in the monitoring area (S25), background image data D5 is generated by integrating the RGB-converted RGB image data D4 in the time axis direction (S26). Then, the background image data is updated as the current background image data D5 and stored in the background image data storage area (S27). The background image data D5 only needs to follow the background such as morning, noon, evening, and nighttime, and can be updated and saved as a background image that reflects changes in the shooting environment if the time constant is set in minutes. .

  In addition, when it is determined that the RGB image data D4 has a change of a predetermined value or more with respect to the background image data D5, and the state change continues for a predetermined number of frames or more, the motion detection processing unit 30 It is determined that there is motion) (S25), and this determination information is set in the motion detection register (S28). On the other hand, if it is equal to or less than the predetermined number of frames, it is determined that there is no moving object (S25).

  If it is determined that there is a moving object, the main control unit 50 does not perform integration processing for generating the background image data D5, and extracts the position and size of the moving object in the captured image and stores them in the same motion detection register. save.

  In this way, it is possible to detect the presence or absence of a moving object in the monitoring area being photographed, extract the position and size of the moving object, and update the background image data D5 as needed to move more accurately. Detection of the presence or absence of a body and the position and size of a moving body can be extracted.

<2-4. Operation to perform exposure processing on subjects with different optimal exposure conditions>
Next, an operation for performing an optimum exposure process on a plurality of subjects having different optimum exposure conditions will be described.

  FIG. 6 is a flowchart showing an exposure process performed on a plurality of subjects having different optimal exposure conditions. First, the block luminance average value calculation unit 41 periodically inputs the luminance data D6a of the odd frame data D2a generated by the camera image processing unit 15 at 15 frames per second. Also, the luminance data D6b of the even frame data D2b is set and inputted as image data only when it is determined that a moving body is detected during backlight as described later (S31).

  Then, the block luminance average value calculating unit 41 divides the screen into 4 × 4 horizontal by 4 with respect to the luminance data D6a of the odd-numbered frame data D2a, and calculates a divided average luminance value by averaging the luminance signal for each divided block. To do. Then, the divided average luminance value for each block is stored in a map register (not shown) for 16 divisions. For the brightness data D6b of the even frame D2b, an overall average brightness value obtained by averaging the brightness signals of the entire screen is calculated, and the overall average brightness value is stored in a backlight moving body brightness register (not shown). (S32).

  Next, the integration processing unit 42 inputs the division average luminance value of each block stored in the map register for 16 divisions, and the “presence / absence” information of the motion detection register set in the register of the main control unit 19. Is checked (S33). When the motion detection register is set to “none”, the divided average luminance value of each block is integrated in the time axis direction in the map state to generate a luminance map of the background image. Then, the brightness map of the background image in a state in which the moving object has not entered is updated and stored (S34).

  Since it is detected that there is no moving body in this way, the AE control unit 22 sets the backlight moving body detection register to “none” by a microcomputer (not shown). Then, the AE control unit 22 obtains an average luminance value of the luminance map of the background image so that the average luminance value becomes a target value (generally a 50% gray value) at both the odd-numbered frame and even-numbered frame imaging timings. Then, the exposure conditions of the exposure control means (the shutter speed of the imaging unit 11, the gain of the AGC circuit 12, etc.) are set (S35).

  In this way, by performing the above-described control on the luminance data D6a and D6b input to the exposure control unit 40, the mobile object in the normal environment area is optimally exposed (target value) when shooting odd frames. 50% gray). Even frames are photographed under the same exposure conditions as the odd frames, but since no moving object is detected, the image data size of the second image data stream D3b generated by the camera image processing unit 15 is zero. There is no need to take unnecessary images.

  On the other hand, when the motion detection register is set to “present”, the AE control unit 43 determines whether or not desired exposure is performed on the moving body (for example, whether or not it is in backlight). Specifically, the AE control unit 43 calculates a deviation value (luminance information for each block) that is a luminance difference between the luminance map data of the background image and the luminance map data of the odd-numbered frame stored in the integration processing unit 42 by the microcomputer. To do. If the deviation value is equal to or greater than a predetermined value, it is determined that the desired exposure is not performed on the moving body by photographing under a backlight environment or the like. Then, the position and size of the moving object stored in the detection register are read and associated with the position of the 16-division background image luminance map stored in the integration processing unit 42. As a result of the association, if the center of gravity of the moving object is within the block area determined to be in the backlight environment of the luminance map of the background image, the backlight moving object detection register is set to “present” and the backlight moving object detection “present” Along with the information, the camera image processing unit 15 is notified of the position and size of the read moving body (S36).

  Next, the AE control unit 43 reads the divided average luminance value of the block containing the center of gravity of the moving object at the timing for setting the exposure of even frames, and the luminance value is the target value (usually 50% gray). The exposure control means is set so that Specifically, the shutter speed of the imaging unit 11 and the gain of the AGC circuit 12 when shooting an even frame are set under conditions obtained by adding the exposure correction calculated for the exposure condition corresponding to shooting of the odd frame D2a. Shooting corresponding to the frame is performed (S37).

  Further, when an image of an even frame has already been generated immediately before, that is, when it is determined that there is a continuous moving body detection process and it is determined that the moving body is continuously in a backlight state, The brightness value stored in the backlight moving body brightness register is compared with the target value, and secondary correction is performed in the direction of reducing the difference with respect to the exposure condition corresponding to the odd-numbered frame shooting (S38).

  In this way, by performing the above-described control on the luminance data D6a and D6b input to the exposure control unit 40, the optimal exposure (target value) can be obtained when the moving body is in backlight when photographing even frames. It is possible to shoot with a setting of 50% gray. Even when the backlight moving object detection is “present”, the shutter speed of the imaging unit 11 and the gain of the AGC circuit 12 are set so that the overall average luminance value of the integration processing unit 42 becomes the target value at the timing of shooting odd frames. Set.

<2-5. Operation for Recording First and Second Image Data Streams>
Next, an operation of recording the first image data stream D3a and the second image data stream D3b generated by performing the exposure control described above in the image recording unit 22 will be described. FIG. 7 is a flowchart showing an operation until the first image data stream and the second image data stream are recorded in the image recording unit 22. FIG. 8 is a diagram illustrating a state in which the first data stream D3a and the second data stream D3b are compressed.

  First, the camera image processing unit 15 multi-streams the first image data stream D3a and the second image data stream D3b subjected to exposure control as described above by time division multiplexing (S41). The multi-stream data D7 is output to the image compression / decompression unit 21 (S42).

  Then, the image compression / decompression unit 17 performs image compression on the multi-stream data D7 under a condition that matches each stream. For example, first, the first image stream for normal recording is compressed by the MPEG4 system of the standard image size (S43), and then the second image stream obtained by photographing the moving body in the backlight with the appropriate exposure is determined in advance. The image is compressed according to the JPEG method according to the image size (S44).

  Note that the image compression / decompression unit 21 does not perform JPEG compression during normal time when there is no moving object during backlighting, because the image size of the second image data stream is zero, and MPEG4 single image compression. become. That is, MPEG4 and JPEG multi-stream image compression is performed only when a moving object is detected during backlighting.

  Next, the image data of the first image data stream compressed by the MPEG4 system is associated with management information such as time information and motion detection under the control of the main control unit 50, and is constantly recorded in the image recording unit 22. (S45). On the other hand, for the image data of the second image data stream, compressed image data is generated only for a predetermined time when the moving object is detected during backlighting, and is associated with the management information of the first image data stream generated at the same time. Then, it is stored in the backlight recording area of the image recording unit 22 (S46).

  As described above, the image monitoring and recording apparatus 1 according to the present embodiment compresses the first image data stream composed of odd-numbered frames using the MPEG4 method and records it in the constant recording area (first recording area) of the recording medium. However, only when a moving body is detected during backlighting, the second image data stream is compressed in the JPEG format and recorded in the backlight recording area (second recording area) of the recording medium.

  As described above, according to the image monitoring and recording apparatus 1 of the present invention, even if there are a plurality of moving bodies in an environment with different optimum exposure conditions, it is possible to perform appropriate exposure on each moving body. As a result, it is possible to accurately capture the intruder's face and clothes. Also, only when a moving object whose proper exposure condition is different from that during normal photographing is detected, a small-size image obtained by photographing the moving object under a special environment is recorded redundantly for a predetermined time, so that the recording capacity is increased redundantly. Therefore, it is possible to store an accurate photographed image such as an intruder's face and clothes required for the image monitoring and recording apparatus.

<Modification>
In the above-described embodiment, the image compression of the first image data stream D3a has been described using the MPEG4 system, and the image compression of the second image data stream D3b is performed using the JPEG system. However, the present invention is not limited to this. Both streams may be unified with MPEG4 or JPEG, and the same effect as in the above-described embodiment can be obtained by combining with other image compression methods. Further, the compressed image data of the first image data stream composed of odd frames is always recorded, but the event recording may be performed only for a predetermined time with the motion detection as a trigger. By performing such event recording, it is possible to record for a long time.

  In the image monitoring and recording apparatus, a live image and a reproduced image can be output to a display device by a display output processing unit (not shown), as in the conventional image monitoring and recording apparatus. Specifically, first, the live image is selectively input to the display output processing unit, and the first image data stream D3a output from the camera image processing unit 15 is output to the external display. The reproduced image is controlled by the main control unit 50 as one or both of the compressed image data of the first image data stream D3a and the compressed image data of the second image data stream D3b stored in the image recording unit 22. Thus, the data is input to the image compression / decompression unit 21, decoded into the original image data, input to the display output processing unit, and output to the external display.

  In addition, the image monitoring and recording apparatus can be used as a remote monitoring terminal through a network, like the conventional image monitoring and recording apparatus. More specifically, when transmitting a live image, MPEG4 compressed data obtained by compressing the first image data stream compressed by the image compression / decompression unit 21 is normally transmitted. Also, only when a moving object is detected during backlighting and the second image data is JPEG compressed, MPEG4 and JPEG are converted into a multi-stream and distributed to a network distribution such as Ethernet (registered trademark). The reproduced image is distributed over the network by using one or both of the first image data stored in the image recording unit 22 and the compressed image data of the second image data stream as a network protocol such as Ethernet (registered trademark). Deliver to.

  In the above-described embodiment, the method for generating and recording the image data of two systems has been described. However, the present invention is not limited to this, and the image data of three or more systems is generated and recorded. Also good. For example, when generating three systems of image data, the recording medium is divided into three, normal recording for the first image frame, backlight-corrected recording for the second image, and dark recording for the third image. If too much, record the exposure control. As described above, even when three or more systems of image data that are repeatedly recorded in the order of normal recording, backlight correction recording, and darkness correction recording are generated, the same effect as the above-described embodiment can be obtained.

  DESCRIPTION OF SYMBOLS 1 Image monitoring recording apparatus, 10 Digital image data generation part, 11 Lens, 12 Imaging part, 13 AGC circuit, 14 AD conversion part, 15 Camera image processing part, 20 Recording part, 21 Image expansion part, 22 Image recording part, 30 Motion detection processing unit, 40 exposure control unit, 41 luminance average value calculation unit, 42 integration processing unit, 43 AE control unit.

Claims (8)

Exposure control means for controlling exposure at the time of shooting, dividing an image signal shot by controlling exposure into an odd frame and an even frame, and the first digital image data from the odd frame to the second from the even frame; A digital image data generator for generating digital image data;
Recording means for recording each of the first digital image data and the second digital image data;
The presence or absence of a moving body is detected from one digital image data of the first digital image data and the second digital image data, and when the moving body is detected, the position and size of the moving body are detected. Motion detection means;
The one digital image data is divided into a plurality of blocks, an average luminance value is calculated for each block, luminance information for each block is calculated from the average luminance value, luminance information for each block and the motion detection unit An image monitoring and recording apparatus, comprising: an exposure control unit that sets an exposure condition of the exposure control unit when shooting the odd frame and the even frame based on a detection result. When it is detected by the motion detection means that the moving body is present,
The exposure control unit determines whether or not desired exposure is performed on the moving body from the luminance information for each block and the detection result of the motion detection unit, and is determined not to be desired exposure. 2. The image monitoring recording according to claim 1, wherein when the frame corresponding to the other digital image data is captured, an exposure condition of the exposure control unit is set so that the moving body has a desired exposure. apparatus.   The exposure control unit calculates a difference between an average luminance value for each block of a background image generated from the one digital image data and an average luminance value for each block of the one digital image data sequentially input. The image monitoring and recording apparatus according to claim 2, wherein the image monitoring and recording apparatus calculates the information and determines that the desired exposure is not obtained when the luminance information is a predetermined value or more. When it is detected by the motion detection means that there is no moving body,
The image monitoring and recording apparatus according to claim 3, wherein the exposure control unit updates an average luminance value for each block of the one digital image data as an average luminance value for each block of the background image.   The recording means compresses the one digital image data and records it in the first area. If it is determined that the exposure is not the desired exposure, the recording means compresses the other digital image data and compresses the second digital image data. The image monitoring recording apparatus according to claim 2, wherein the image monitoring recording apparatus records in an area. The digital image data generation unit multistreams the first digital image data and the second digital image data and outputs the multistream;
The recording means compresses the one digital image data and records it in the first area in association with management information such as time information and motion detection, and compresses the other digital image data to perform the management. The image monitoring recording apparatus according to claim 5, wherein the image monitoring recording apparatus records information in the second area in association with information. When the exposure control unit determines that it is not the desired exposure,
The digital image data generation unit generates the other digital image data including an area obtained by cutting out the position and size of the moving body detected by the motion detection unit. The image monitoring recording apparatus described in 1.   The said exposure control part determines whether the said moving body exists in a backlight environment from the luminance information for every said block, and the detection result of the said detection means, The one in any one of Claims 2-7 Image monitoring and recording device.

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