JP2004247817A - Image pickup and transmission system, method of controlling display recording apparatus, and method of controlling image pickup apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a superior image pickup and transmission system capable of preventing overlooking, and to provide a method of controlling a display recording apparatus and a method of controlling an image pickup apparatus. <P>SOLUTION: The image pickup apparatus 10 picks up an image, and encodes the picked-up image to transmit it. A decoding control apparatus 30 has a display unit 42, and decodes the image to be transmitted from the apparatus 10 and displays the decoded image. The apparatus 30 is provided with a data storing unit 44 serving as a storing means for temporarily storing the image. A CPU 32 controls a speed at which the image is read from the unit 44. Control is performed to lower the read-out speed from a predetermined standard read-out speed to a predetermined overlooking prevention read-out speed slower than the standard read-out speed. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a system for transmitting an image between an imaging device and a display device connected via a network, a display recording device and a control method of the imaging device therefor, and a technique for facilitating monitoring of a subject.
[0002]
[Prior art]
Conventionally, as a monitoring system, a system for connecting an imaging device and a display device via a network has been proposed. In this type of system, display and recording of an image on a display device are usually performed in real time.
[0003]
FIG. 5 shows a conventional monitoring system connected to a network. In the figure, LANs 100 and 102 are connected to a public network 106 via a relay device 104. Branch LANs 110, 112, 114, and 116 are connected to the LANs 100 and 102 via a relay device 108. LANs 100 and 102 are ATM, Ethernet (registered trademark), IEEE 1394, etc., relay device 104 is a router, a brouter, etc., public network 106 is ISDN, Ethernet (registered trademark), etc., and relay device 108 is a bridge or hub. The branch LANs 110, 112, 114, and 116 are Ethernet (registered trademark), IEEE 1394, or the like.
[0004]
On the branch LANs 110, 112, 114, and 116, a camera 118 and a camera control device 120 are provided. The camera control device 120 switches and controls the camera 118 via a network. For example, the camera 118 on the branch LAN 110 is selected by the camera control device 120 on the branch LAN 112. In the camera 118, the captured image is encoded using an image compression technique such as MPEG. The camera 118 sends the encoded image to the camera control device 120 via the branch line LAN 110, the LAN 100, and the branch line LAN 112. In the camera control device 120, the transmitted image is encoded, displayed, and recorded.
[0005]
This type of monitoring system is disclosed in, for example, Patent Document 1.
[0006]
[Patent Document 1]
JP-A-11-12929 (4th page, FIG. 1)
[0007]
[Problems to be solved by the invention]
In an image captured by the surveillance system, a short-time important image that should not be overlooked, such as an instant crime, is included in a part of the entire long image. On the other hand, in the conventional monitoring system, as described above, the display speed of an image is linear and constant in real time. Therefore, an image such as an instant crime, and other general images are displayed at a constant speed. Therefore, it may not be easy to keep important images from being missed.
[0008]
Here, the background of the present invention has been described with reference to the monitoring system. However, it is similarly desired that the image transmission system other than the monitoring system can surely confirm the image without missing the image.
[0009]
The present invention has been made under the above background, and an object of the present invention is to provide an excellent imaging transmission system, a display recording device control method, and an imaging device control method which can prevent the above-mentioned oversight. .
[0010]
[Means for Solving the Problems]
The imaging transmission system of the present invention includes an imaging device that captures an image, encodes the captured image, and transmits the image, and a display device that is connected to the imaging device via a network, decodes the transmitted image, and displays the decoded image. A storage unit for temporarily storing an image, and a reading speed of the image from the storage unit is reduced from a predetermined standard reading speed to a predetermined reading prevention speed lower than the standard reading speed. Oversight prevention control means for controlling the vehicle.
[0011]
With this configuration, since the image is temporarily stored and the reading speed is controlled to be low, it is possible to display the image which should not be overlooked at a low speed and more surely check the image. It is possible to effectively prevent an instantaneous crime image to be overlooked. The storage means is preferably provided in the display device, but may be provided in the imaging device.
[0012]
Further, the imaging transmission system of the present invention includes a recording unit that records an image read from the storage unit at the oversight prevention reading speed.
[0013]
With this configuration, an image with a low reading speed for preventing oversight is recorded, so that storage and reproduction can be performed and oversight can be prevented.
[0014]
Further, the imaging transmission system of the present invention has a detection unit for detecting the presence of a subject to be prevented from being overlooked, and the oversight prevention control unit is configured to detect an image from the storage unit according to a detection result of the detection unit. Control the reading speed.
[0015]
With this configuration, it is possible to read out and display at a low speed an image having a high possibility that an object to be overlooked is captured, and to more reliably prevent the oversight.
[0016]
Further, in the imaging transmission system of the present invention, the oversight prevention control means, when the storage data amount (remaining data amount) of the storage means increases due to a low-speed reading process from the storage means, causes the storage means to perform an oversight. A process for preferentially discarding the stored inter-coded frames is performed.
[0017]
With this configuration, it is possible to effectively limit an increase in the amount of data in the storage unit without causing an unreproducible state due to lack of an intra-coded frame in a compressed image such as MPEG. More preferably, an increase in the amount of accumulated data is limited by performing a process of preferentially discarding frames that are not referred to by other frames during decoding, even in intra-coded frames, so as not to cause a reproduction impossible state. I do.
[0018]
Also, the imaging transmission system of the present invention may be configured such that, when an image is read from the storage means at the oversight prevention reading speed under the control of the oversight prevention control means, the imaging speed of the imaging device is changed to the oversight prevention reading speed. May be provided.
[0019]
According to this configuration, it is possible to effectively limit an increase in the amount of data stored in the storage unit when the reading speed is reduced due to a reduction in the imaging speed.
[0020]
An imaging transmission system according to another aspect of the present invention includes an imaging device that captures an image, encodes the captured image, and transmits the image, and a display that is connected to the imaging device via a network and decodes and displays the transmitted image. A storage device for temporarily storing images; and increasing the imaging speed of the imaging device from a predetermined standard imaging speed to a predetermined oversight prevention imaging speed higher than the standard imaging speed. And an image pickup speed control means for controlling the image pickup speed so as to reduce the display speed on the display device by accumulating the image picked up at the oversight prevention image pickup speed in the storage means.
[0021]
According to this configuration, the number of frames increases due to an increase in the imaging speed, and the display speed on the display device decreases accordingly, so that oversight can be effectively prevented.
[0022]
Further, the imaging transmission system of the present invention has a detection unit for detecting the presence of a subject to be prevented from being overlooked, and the imaging speed control unit controls an imaging speed of the imaging device according to a detection result of the detection unit. Control.
[0023]
With this configuration, it is possible to display an image having a high possibility that an object to be prevented from being missed is displayed at a low speed, and it is possible to more reliably prevent an oversight.
[0024]
Also, in the control method of the display recording apparatus according to the present invention, the image is temporarily stored in the storage unit, and the reading speed of the image from the storage unit is changed from the predetermined standard reading speed to a predetermined reading speed lower than the standard reading speed. The storage readout control for controlling the readout speed to the escape prevention readout speed is performed.
[0025]
With this configuration, as described above, the image is temporarily stored, and the reading speed is controlled so as to be low. Therefore, the image that should not be overlooked is displayed at low speed, and the image can be confirmed more reliably. It becomes possible.
[0026]
Further, in the control method of the display recording device of the present invention, an image read from the storage means at the oversight prevention reading speed is recorded in the recording means.
[0027]
According to this configuration, since an image at the readout prevention readout speed is recorded, storage and reproduction can be performed, and it is possible to prevent an oversight.
[0028]
Further, the control method of the display recording apparatus of the present invention controls the reading speed of the image from the storage means according to the detection result of the presence of the subject to be prevented from being overlooked.
[0029]
With this configuration, it is possible to read out and display at a low speed an image having a high possibility that an object to be overlooked is captured, and to more reliably prevent the oversight.
[0030]
The control method of the imaging device according to the present invention increases an imaging speed of the imaging device from a predetermined standard imaging speed to an oversight prevention imaging speed higher than the standard imaging speed, and increases a display speed of the display device. Control to lower.
[0031]
According to this configuration, the number of frames increases due to an increase in the imaging speed, and the display speed decreases accordingly, so that oversight can be effectively prevented.
[0032]
Further, in the control method of the imaging device according to the present invention, the imaging speed of the imaging device is controlled in accordance with a detection result of the presence of a subject to be prevented from being overlooked.
[0033]
With this configuration, it is possible to display an image having a high possibility that an object to be prevented from being missed is displayed at a low speed, and it is possible to more reliably prevent an oversight.
[0034]
The present invention is not limited to the above embodiments. Another embodiment of the present invention is, for example, an imaging device or a display recording device, and another embodiment is, for example, executed by a computer to realize the device or method of the present invention. And a medium on which such a program is recorded, for example.
[0035]
The present invention is suitably applied to a surveillance system using a so-called surveillance camera, but can also be applied to an imaging transmission system other than the surveillance system.
[0036]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0037]
FIG. 1 shows an imaging transmission system according to a first embodiment of the present invention. An imaging device 10 having a camera is connected via a LAN 50 to a decoding control device 30 having a decoding display function. The configuration of FIG. 1 is obtained by extracting a part of the monitoring system shown in FIG.
[0038]
First, referring to FIG. 2, the LAN 50 is connected to branch LANs 56 and 58 via relay devices 52 and 54. The LAN 50 is an ATM, Ethernet (registered trademark), IEEE 1394, or the like. The relay devices 52, 54 are bridges, hubs, and the like, and the branch LANs 56, 58 are Ethernet (registered trademark), IEEE 1394, and the like.
[0039]
The imaging device 10 and the decode control device 30 are provided on the branch lines 56 and 58. The imaging device 10 has an imaging element such as a CCD, an imaging function related thereto, and a communication function using the LAN 50.
[0040]
The decoding control device 30 corresponds to a control device of the imaging device 10 and has a function of switching and controlling the imaging device 10. Further, the decode control device 30 further has a function of displaying and displaying a video, and corresponds to the display device of the present invention. The decoding control device 30 may be constituted by a personal computer. In this case, the personal computer executes a program for realizing the decoding control device according to the present invention. Then, the decoding control device 30 displays the image transmitted from the imaging device 10.
[0041]
For example, an image captured by the imaging device 10 of the branch line LAN 56 is transmitted to the decode control device 30 of the branch line LAN 58 through the branch line LAN 56, the relay device 52, the LAN 50, the relay device 54, and the branch line LAN 58.
[0042]
Returning to the description of FIG. 1, also in FIG. 1, the imaging device 10 on the branch LAN 56 is connected to the decode control device 30 on the branch LAN 58 via the LAN 50, as in the above example.
[0043]
As shown in FIG. 1, an imaging device 10 includes an imaging control unit 12 that controls an imaging element (not shown) to generate an image, an encoding unit 14 that compresses and codes the generated image, It has a communication processing unit 16 for transmitting encoded data, and the communication processing unit 16 is connected to the LAN 50 via the communication I / F unit 18. In the present embodiment, the encoding unit 14 is configured by a CPU that controls the entire apparatus, and compresses an image by a process based on MPEG.
[0044]
On the other hand, the decoding control device 30 includes a CPU 32 that controls the entire device, and a communication processing unit 34 for receiving transmitted images and other information. The communication processing unit 34 includes a communication I / F unit 36. It is connected to the LAN 50 through the LAN. Further, the decoding control device 30 is provided with a UI unit 38 that receives a user's instruction operation of a keyboard or the like, and an instruction of the user is transmitted to the CPU 32 via the UI unit 38. Further, the decoding control device 30 includes a decoder 40 for decoding the transmitted compressed image, and a display unit 42 for displaying the decoded image. The display unit 42 includes a display such as a CRT.
[0045]
Further, as shown in FIG. 1, the decoding control device 30 is provided with a data storage unit 44 for temporarily storing images transmitted from the imaging device 10. The data storage unit 44 is configured by a buffer memory. In accordance with an instruction from the CPU 32, accumulation of an image in the data accumulation unit 44 and reading of an image from the data accumulation unit 44 to the decoder 40 are controlled. As will be described later, the CPU 32 has a function of controlling the reading speed of the data storage unit 44. With this function, the display speed is reduced, and an oversight of an event such as an instant crime is effectively prevented.
[0046]
The decoding control device 30 is provided with a sensing unit 46. The sensing unit 46 is for detecting the presence or absence of a subject to be prevented from being overlooked. In the present embodiment, the sensing unit 46 performs image sensing. That is, a subject to be prevented from being overlooked is detected from the image by the image processing.
[0047]
Next, the operation of the system of FIG. 1 will be described. The user operates a keyboard, a pointing device, and the like (not shown) to perform an operation of selecting the imaging device 10 to be controlled by the decode control device 30. This operation is received by the CPU 32 via the UI unit 38. In the example shown in FIG. 1, the imaging device 10 on the branch LAN 56 has been selected by the decode control device 30 on the branch LAN 58, and the camera has already been switched to the imaging device 10 on the branch LAN 56 in accordance with this selection operation. ing.
[0048]
When the imaging device 10 and the decoding control device 30 are connected, monitoring is performed by transmitting an image captured by the imaging device 10 to the decoding control device 30 and displaying the image on the decoding control device 30 as described below.
[0049]
In the imaging device 10, an image is generated by the imaging control device 12 using an imaging device such as a CCD. The generated image is compression-encoded by the MPEG unit in the encoding unit 14. The encoded image is transmitted from the communication processing unit 16 to the LAN 50 via the communication I / F unit 18.
[0050]
In the decoding control device 30, the communication processing unit 32 receives an image from the LAN 50 via the communication I / F unit. The received image is temporarily stored in the data storage unit 44 under the control of the CPU 30. Further, under the control of the CPU 30, an image is read from the data storage unit 44 and sent to the decoder 40. Then, the image is decoded by the decoder 40, and the decoded image is displayed on the display unit 42. The image is recorded on a recording unit such as a hard disk (not shown).
[0051]
During normal monitoring, the image transmitted to the decoding control device 30 is stored in the data storage unit 44 and is immediately read. The storage and reading speeds are controlled to be the same, and the decoding control device 30 performs display in real time. The reading speed from the data storage unit 44 at this time is a predetermined standard reading speed. On the other hand, in the present embodiment, the reading speed is controlled in the following situations.
[0052]
The sensing unit 46 performs image sensing to detect the presence or absence of a subject to be prevented from being overlooked in the image. For example, the presence or absence of a moving subject is detected. The detection result of the sensing unit 46 is sent to the CPU 32. When the information indicating the existence of the subject to be prevented from being overlooked is acquired, the CPU 32 controls the reading speed from the data storage unit 14 and changes the reading speed to the predetermined oversight preventing reading speed. The oversight prevention reading speed is a value lower than the standard reading speed for real-time display, and is set in advance to an appropriate speed for preventing the subject from being overlooked, for example, half the standard reading speed. I have.
[0053]
By the speed control described above, the image is read from the data storage unit 44 at the readout prevention read speed. Then, the read image is decoded by the decoder 40 and displayed on the display unit 42. As the reading speed decreases, the speed at which an image is sent to the decoder 40 also decreases. Then, the image is temporarily displayed at a speed lower than the real-time display speed, whereby an easy-to-view image is displayed. The low-speed image is recorded on a recording unit such as a hard disk (not shown).
[0054]
In the above description, the image reading speed from the data storage unit 44 is changed in response to the sensing, but the image reading speed is also changed by a user operation. That is, when the user looks at the display unit 42 and thinks that an image to be prevented from being missed is captured, the user performs a predetermined operation on an operation device such as a keyboard. This operation is received by the CPU 32 via the UI unit 38 of the decoding control device 30. Then, the CPU 32 reduces the reading speed of the image from the data storage unit 44. Also at this time, the reading speed is changed to the above-described oversight prevention reading speed. Therefore, the display unit 42 displays an image at a speed lower than the normal real-time display speed.
[0055]
FIG. 3 is a flowchart showing a preferred operation example of the decoding control device 30. As will be described later, FIG. 3 shows an appropriate process in consideration of the overflow of the data storage unit 44.
[0056]
As shown in the drawing, when the UI unit 38 of the decoding control device 30 acquires a user operation, the imaging device 10 is selected (S10), and monitoring by displaying an image transmitted from the imaging device 10 is started (S12). . At this time, in the decoding control device 30, the image is read from the data storage unit 44 at the standard reading speed, and the image is displayed in real time.
[0057]
After the start of the monitoring, the CPU 32 of the decoding control device 30 determines whether there is any sensing or a predetermined user operation (S14). When the sensing unit 18 detects a subject to be prevented from being overlooked, or when an operation for changing the speed is received by the UI unit 38, the determination in S14 is YES. Then, under the control of the CPU 32, the reading speed of the data storage unit 44 is changed from the standard reading speed to the oversight prevention reading speed, and low-speed reading is performed (S16).
[0058]
When the low-speed reading is performed, the storage speed of the data storage unit 42 exceeds the read speed, and the amount of stored data (remaining data amount) of the data storage unit 42 increases. Therefore, the CPU 32 refers to the amount of data stored in the data storage unit 46 and determines whether or not the data storage unit 46 is full (full) based on whether or not the stored data amount has reached a predetermined full reference value. (S18).
[0059]
If the data storage unit 46 is not full (NO in S18), the process returns to S16 and low-speed reading is performed. When the data storage unit 46 is full (the determination in S18 is YES), the data in the data storage unit 46 is skipped, and the data is discarded (S20).
[0060]
In the idle reading process according to the present embodiment, a process of changing a pointer to a frame in the data storage unit 46 is performed. As a result, a frame that has not been read yet is treated as having already been read. Therefore, some frames end without being displayed, that is, are discarded.
[0061]
Further, in the blank reading process of the present embodiment, as described below, a process of performing blank reading with priority on the inter-coded frame is performed. As is well known, MPEG data is composed of an intra-coded frame called an I-picture and an inter-coded frame called a P-picture and a B-picture. Among them, in the present embodiment, the inter-coded frames are preferentially skip-read, and, in particular, frames that are not referred to by other frames in the decoding process are preferentially skip-read. For example, the frame immediately before the I picture is preferentially skipped.
[0062]
As described above, in the present embodiment, the inter-coded frames are preferentially discarded, and in particular, discarded sequentially from a frame that is not referred to by other frames. Conventionally, processing for discarding a part of frames forming a GOP of MPEG data has not been seen, but in the present embodiment, by performing such processing, the amount of data stored in the data storage unit 46 can be reduced. Can be effectively limited.
[0063]
As shown in the drawing, the CPU 32 further determines whether or not a predetermined set time has elapsed with reference to the elapsed time since the data storage unit 46 became full (S22). The set time is set to an appropriate value that does not cause the data storage unit 46 to further increase and overflow. If the set time has not elapsed, the process returns to S16, where low-speed reading from the data storage unit 46 and accompanying low-speed display are performed. After the elapse of the set time, the process returns to S14, where the image is read again from the data storage unit 46 at the standard reading speed, and the real-time display of the image is restarted. Then, the CPU 32 waits for the next sensing or operation.
[0064]
As described above, according to the present embodiment, an image is temporarily stored, and the reading speed is controlled so as to be low, so that an image that is more easily viewable is obtained.
[0065]
Conventionally, the speed of imaging, transmission and display during imaging is constant in real time, and even if a situation requiring attention occurs, it may not be easy to reliably monitor such a situation. . On the other hand, according to the present embodiment, since the low-speed readout control using the above-described temporary storage unit is performed, it is easy to perform monitoring without overlooking a cautionary image.
[0066]
Further, in the above-described embodiment, since the image read from the storage means at the oversight prevention reading speed is recorded in the recording means, the image can be saved and played back, so that the oversight can be prevented. .
[0067]
In the above-described embodiment, the presence of the subject to be prevented from being overlooked is detected, and the reading speed of the image from the storage unit is controlled according to the detection result. An image with a high possibility can be displayed at a low speed, and oversight can be prevented more reliably.
[0068]
In the above-described embodiment, when the amount of stored data increases due to the low-speed reading process from the data storage unit serving as the storage unit, the process of preferentially discarding the stored inter-frame encoded frames is performed. . As a result, when a compressed image such as MPEG is transmitted, an increase in the amount of data in the storage means can be effectively limited without causing a reproduction impossible state due to lack of an intra-frame.
[0069]
In the above-described embodiment, as shown in FIG. 1, the configuration in which the imaging devices and the decoding control devices of different branch LANs are connected via the LAN has been described. However, the imaging device may be controlled by the decode control device on the same branch LAN within the scope of the present invention. Further, the imaging device may be controlled by the decode control device via another network such as a public network (see FIG. 5).
[0070]
Further, in the above-described embodiment, as shown in FIG. 1, a data storage unit as a buffer is provided in the decode control device. However, within the scope of the present invention, a data storage unit performing a similar function may be provided on the imaging device side and controlled through a network.
[0071]
In the above-described embodiment, the sensing unit performs image sensing. However, the sensing unit is not limited to one that performs image sensing. The sensing unit may be a sensor attached to the outside, for example, a sensor provided at the installation location of the imaging device. A so-called motion sensor may be provided. Further, the sensing unit may be provided in the imaging device, and a detection result may be sent from the imaging device to the decoding control device.
[0072]
In the above-described embodiment, when the amount of data stored in the data storage unit is increased, the data is discarded by the idle reading, and an overflow is avoided by checking the progress of the time setting value. On the other hand, when the data storage unit is about to overflow, decoding may be performed at a speed higher than the normal decode display speed, thereby reducing the amount of data stored in the data storage unit. That is, the amount of data stored in the data storage unit is referred to, it is determined whether or not the data value has reached a predetermined value. When the data value reaches the predetermined value, the reading speed from the data storage unit is increased. According to this processing, the amount of accumulated data can be reduced without discarding the data.
[0073]
Further, as another process in consideration of the overflow of the data storage unit, the imaging speed of the imaging device may be reduced. According to this configuration, it is possible to effectively limit an increase in the amount of data stored in the storage unit when the reading speed is reduced due to a reduction in the imaging speed.
[0074]
As a more specific embodiment, when the decoding control device performs control to reduce the reading control of the data storage unit, the decoding control device sends an instruction to reduce the imaging speed to the imaging device. In response, the imaging device reduces the imaging speed to a predetermined speed. To change the imaging speed, for example, the clock frequency is controlled and changed. Since the storage speed in the data storage unit decreases due to the decrease in the imaging speed, the increase in the amount of stored data due to the decrease in the read speed is limited.
[0075]
The above-described process of reducing the imaging speed may be started after the low-speed readout control is started and the amount of data stored in the storage unit is increased to some extent. The stored data amount is referred to, and when the stored data amount reaches a predetermined value, low-speed imaging is started. More specifically, in the system of FIG. 1, an instruction to lower the imaging speed is sent from the decoding control device to the imaging device, and in response to this, the imaging device lowers the imaging speed. This configuration also limits an increase in the amount of stored data.
[0076]
Next, a second embodiment of the present invention will be described with reference to FIG. In the modification of the above-described first embodiment, the increase in the amount of data stored in the data storage unit on the decoding side is limited by reducing the imaging speed by controlling the imaging speed. The imaging speed is also controlled in the second embodiment. Here, as described below, instead of reducing the imaging speed, control for increasing the imaging speed is performed. And the display speed on the decoding side is reduced.
[0077]
In FIG. 4, the same components as those in the first embodiment shown in FIG. 1 are denoted by the same reference numerals. Hereinafter, the description of the same items as in the first embodiment will be appropriately omitted.
[0078]
As shown in FIG. 4, in the present embodiment, the data storage unit 20 is provided in the imaging device 10, and the imaging control unit 12 of the imaging device 10 functions as an imaging speed control unit, and controls the imaging speed. Control.
[0079]
As an operation of the system in FIG. 4, when monitoring is started, the imaging control unit 12 sets the imaging speed to a predetermined standard imaging speed. The captured image is encoded by the encoding unit 14 and temporarily stored in the data storage unit 20. The encoded data is read from the data storage unit 20 and sent to the decode control device 30 via the LAN 50. As a result, an image is displayed on the display unit 42 of the decoding control device 30 in real time.
[0080]
When the sensing unit 46 of the decode control device 30 detects a notable subject, or when a user operation instructing a decrease in the display speed is received by the UI unit 38, the CPU 32 of the decode control device 30 increases the imaging speed. Is transmitted to the imaging device 10 by communication.
[0081]
In response to this instruction, in the imaging device 10, the imaging control unit 12 changes the imaging speed from the standard imaging speed up to that time to a predetermined oversight prevention imaging speed. The oversight prevention imaging speed is set higher than the standard imaging speed. The control of the imaging speed is performed, for example, by changing the clock frequency.
[0082]
Images captured at the oversight prevention imaging speed are processed in the same manner as images at the standard imaging speed. That is, the captured image is encoded, temporarily stored in the data storage unit 20, and then sent to the decode control device 30. Then, the encoded data is temporarily stored in the data storage unit 44 on the decoding side, then read out, decoded, and displayed.
[0083]
In the above-described processing, the number of frames (frame rate) increases due to an increase in the imaging speed. Therefore, even if the processing speed on the decoding side is the same, the speed of the displayed image is lower than the real-time display. It can also be said that the reading speed from the data storage unit 44 is relatively reduced by the increase in the imaging speed and the storage speed in the data storage unit 44. It should be noted that the oversight prevention imaging speed is set in advance so that the display speed on the decoding side is an appropriate speed for preventing oversight of the subject, and is, for example, 1.5 times the standard imaging speed. .
[0084]
Further, as is apparent from the above description, in the present embodiment, the display speed can be changed by controlling the imaging speed, and therefore, the low speed of the data storage unit 44 described in the first embodiment shown in FIG. The display speed can be changed without performing read control. However, it goes without saying that low-speed reading control may be performed in addition to controlling the imaging speed.
[0085]
Further, in the present embodiment, since the imaging speed is increased, the accumulation speed of the data accumulation unit 44 is increased, and the amount of accumulated data is accordingly increased. In response to this, it is preferable to limit the increase in the amount of stored data by the processing such as the idle reading described in the embodiment of FIG.
[0086]
As described above, according to the present embodiment, the number of frames increases with an increase in the imaging speed, and the display speed on the display device decreases with the increase, so that oversight can be effectively prevented.
[0087]
Conventionally, the speed of imaging, transmission, and display during imaging is constant in real time, and even if a situation requiring attention occurs, it is sometimes difficult to reliably monitor such a situation. there were. On the other hand, according to the present embodiment, the display speed can be temporarily reduced by controlling the imaging speed as described above, and it becomes easy to perform monitoring without overlooking a cautionary image. .
[0088]
【The invention's effect】
As described above, the present invention can provide an imaging transmission system having an excellent effect that an image can be prevented from being overlooked by providing a temporary storage unit for an image and controlling the reading speed thereof.
[Brief description of the drawings]
FIG. 1 is a block diagram showing an imaging transmission system according to an embodiment of the present invention.
FIG. 2 is a block diagram illustrating an imaging transmission system according to an embodiment of the present invention.
FIG. 3 is a flowchart showing the operation of the imaging transmission system according to the embodiment of the present invention;
FIG. 4 is a block diagram showing an imaging transmission system according to another embodiment of the present invention.
FIG. 5 is a block diagram showing a conventional imaging transmission system.
[Explanation of symbols]
10 Imaging device
12 Imaging control unit
14 Encoding unit
30 Decoding control device
32 CP
40 decoder
42 Display
44 Data storage unit
46 Sensing unit
50 LAN

Claims (12)

An imaging device that captures an image, encodes the captured image, and transmits the encoded image;
A display device connected to the imaging device via a network to decode and display the transmitted image,
An imaging transmission system comprising:
Storage means for temporarily storing images, and an oversight for controlling the reading speed of the image from the storage means to be reduced from a predetermined standard reading speed to a predetermined reading prevention reading speed lower than the standard reading speed. An imaging transmission system comprising a prevention control means. The imaging transmission system according to claim 1, further comprising a recording unit that records an image read from the storage unit at the oversight prevention reading speed. Having a detecting means for detecting the presence of a subject to be prevented from being overlooked,
The imaging transmission system according to claim 1, wherein the oversight prevention control unit controls a reading speed of an image from the storage unit according to a detection result of the detection unit. The oversight prevention control means, when the amount of data stored in the storage means increases due to the low-speed reading processing from the storage means, preferentially discards the inter-frame coded frames stored in the storage means. The imaging transmission system according to any one of claims 1 to 3, wherein: When an image is read from the storage unit at the oversight prevention reading speed under the control of the oversight prevention control unit, an imaging speed control unit that reduces the imaging speed of the imaging device according to the oversight prevention reading speed is provided. The imaging transmission system according to claim 1, wherein the imaging transmission system is provided. An imaging device that captures an image, encodes the captured image, and transmits the encoded image;
A display device connected to the imaging device via a network to decode and display the transmitted image,
An imaging transmission system comprising:
Accumulation means for temporarily accumulating an image; imaging speed control means for controlling the imaging speed of the imaging device to increase from a predetermined standard imaging speed to a predetermined oversight prevention imaging speed higher than the standard imaging speed; and And an image captured at the oversight prevention imaging speed is stored in the storage unit, so that a display speed on the display device is reduced. Having a detecting means for detecting the presence of a subject to be prevented from being overlooked,
The imaging transmission system according to claim 6, wherein the imaging speed control unit controls an imaging speed of the imaging device according to a detection result of the detection unit. A control method of a display recording device that captures an image, decodes an image transmitted from an imaging transmission device that encodes the captured image, and displays and records the image.
An image storing means for temporarily storing an image in a storage means and controlling the reading speed of the image from the storage means to be reduced from a predetermined standard reading speed to a predetermined reading prevention reading speed lower than the standard reading speed; A control method for a display recording device, comprising: performing read control. 9. The control method for a display recording apparatus according to claim 8, wherein an image read from said storage means at said oversight prevention reading speed is recorded in a recording means. The method according to claim 8 or 9, wherein a reading speed of an image from the storage unit is controlled according to a detection result of the presence of a subject to be prevented from being overlooked. A method for controlling an imaging device that captures an image, encodes the captured image, and transmits the encoded image to a display device,
The imaging speed in the imaging device is increased from a predetermined standard imaging speed to an oversight prevention imaging speed higher than the standard imaging speed, and control is performed to decrease the display speed in the display device. Control method of an imaging device. 12. The control method according to claim 11, wherein an imaging speed of the imaging device is controlled according to a detection result of the presence of a subject to be prevented from being overlooked.

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