JP2019022028A - Imaging apparatus, control method and program thereof - Google Patents

Abstract

To detect a subject on the outside of a screen, and to turn a camera to the existing direction of the subject by PTZ.SOLUTION: An imaging apparatus includes an optical part for capturing the light in the normal photographic range and the light outside the photographic range, an image pick-up device part for acquiring an optical image formed in the optical part, a detector for detecting the light outside the photographic range from the output of the image pick-up device part, and a drive part for changing the normal photographic range by panning, tilting and zoom operations. When the detector detects light of a prescribed value or more, a determination is made that a subject exists on the outside of the photographic range, and the drive part is driven to photograph the subject within the normal photographic range.SELECTED DRAWING: Figure 3

Description

  The present invention relates to an imaging apparatus, and more particularly, to an imaging apparatus that detects a subject outside an angle of view and changes a shooting range by panning, tilting, zooming, and the like.

  A network camera using an imaging device is often used for monitoring purposes, and can acquire a higher-definition image than an analog monitoring camera that has been used so far. In recent years, it has become possible to acquire high-definition images at night by improving the S / N of image sensors. Especially in night parking lots, there are many blind spots that are not visible to the public, and it is easy for kidnapping and automatic theft to occur, so the installation of network cameras is very effective.

  In the conventional parking lot technology, even when there is a large change in brightness in the image due to headlights in parking lot monitoring, there is a technology for taking a picture without missing a shot (Patent Document 1) or while sensing a vehicle. There is a technique (patent document 2) that transfers a monitoring image to the host side when another subject exists in the screen.

JP 2009-302763 A Japanese Patent Laid-Open No. 2000-276689

  However, in the above technique, there is a problem that the subject cannot be photographed when the subject to be photographed exists outside the screen. In particular, parking is vast and it is difficult to capture all areas with high definition. For example, if a wide-angle lens is used to capture the entire parking area, the resolution is insufficient and important information cannot be acquired from the monitored video.

  On the other hand, it is conceivable to install many cameras having ordinary lenses, but the installation cost is high. Therefore, in order to monitor a vast parking area, a technique for detecting the presence of a subject outside the screen and changing the shooting range in the direction in which the subject exists is required.

In order to solve the above problems, an imaging apparatus according to the present invention provides:
An optical unit that captures light in the normal shooting range, light outside the shooting range, an image sensor unit that acquires an optical image formed by the optical unit, and detects light outside the shooting range from the output of the image sensor unit And a drive unit that changes the normal shooting range by panning, tilting, zooming operation, and the like,
When the detection unit detects light of a predetermined value or more, the driving unit is driven so that a subject existing outside the shooting range is reflected in the normal shooting range.

  According to the imaging device of the present invention, even when a desired subject exists outside the imaging screen of the imaging device, the desired subject can be photographed by changing the photographing range. Since the imaging apparatus according to the present invention is more effective as the subject is brighter, it is particularly effective for a vehicle in which the headlight is turned on at night.

The block diagram which shows the structure of the imaging device based on 1st embodiment of this invention. The figure explaining the generation | occurrence | production cause of the ghost based on the 1st Embodiment of this invention The flowchart which changes the imaging | photography range, if the ghost is detected based on the 1st Embodiment of this invention. The flowchart which changes the imaging | photography range, if the direction of a ghost is detected based on the 1st Embodiment of this invention. Explanatory drawing which detects the direction of a ghost based on the 1st Embodiment of this invention. The flowchart which changes the imaging | photography range, if the position or brightness of the detected ghost changes based on the 1st Embodiment of this invention. Explanatory drawing explaining the change in the position or brightness of the detected ghost based on the 1st Embodiment of this invention. The flowchart which changes an imaging | photography range by predicting a movement, if the position of the detected ghost changes based on the 1st Embodiment of this invention. Explanatory drawing regarding prediction of the motion of the detected ghost based on the 1st Embodiment of this invention.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Hereinafter, an internal configuration diagram of the imaging apparatus 101 according to the first embodiment of the present invention will be described with reference to FIG. 1.

  Reference numeral 102 denotes a lens group that can receive not only light within the field angle but also light outside the field angle. The lens group 102 appears in the image as a ghost when more light outside the angle of view is incident than light within the angle of view.

  Reference numeral 103 denotes an image sensor unit, which has a function of changing to an image signal in accordance with light from the lens group 102. The image sensor unit 103 also has a function of converting an image signal, which is an analog electric signal, into a digital signal by A / D conversion processing.

  Reference numeral 104 denotes a CPU unit, which is an arithmetic unit having functions of the development processing unit 105, the detection unit 106, the control unit 107, and the NW unit 109. The development processing unit 105 performs development processing of the video signal raw data. The output from the image sensor unit 103 is a signal obtained by directly converting received light information called a RAW signal into a digital signal. This signal is subjected to processing such as hue, saturation, contrast, noise processing, and edge enhancement in the development processing unit 105, and converted into an image such as RGB or YUV. The detection unit 106 detects whether a ghost exists in the image developed by the development processing unit 105. As will be described later, the detection unit can detect not only the ghost but also the size and orientation of the ghost. Reference numeral 107 denotes a control unit. If it is determined from the detection result of the detection unit 106 that there is a ghost, it is assumed that the subject exists outside the screen, and the driving unit 108 includes the imaging device so that the subject is included in the screen. 100 drive. The drive unit 108 changes the shooting range of the imaging apparatus 101 by panning, tilting, zooming, and the like. The NW unit 109 is a network processing circuit, which converts the output from the development processing 105 in accordance with a communication protocol, and distributes it on the network.

  Reference numeral 110 denotes a local area network (LAN) on the network.

  A client terminal device (PC) 111 is connected to the imaging device via the LAN 110. The client terminal device 111 performs various controls by receiving video of the imaging device using a control tool (not shown) and transmitting control information for controlling the imaging device.

  Next, with reference to FIG. 2, the principle of ghosting will be described.

  FIG. 2 is an enlarged view of the lens group 102. Note that FIG. 2 includes four lenses (201, 202, 203, 204) as an example of ghost generation. Of the four lenses, 201 is a front lens and 204 is a rear lens. Reference numeral 205 denotes an image sensor unit 103 having a function of changing to an image signal in accordance with light from the lens group 102. The angle of view of the lens group 102 is in a range indicated by a solid line 206. A broken line 207 is light within the angle of view, and a broken line 208 is light outside the angle of view. The lens group 201 can condense both of these lights on the image sensor unit 102.

  As shown in FIG. 2, the light 208 outside the angle of view passes through the front lens 201 and is partially reflected by the second lens 202. This light is reflected again by the front lens 201 and finally received by the image sensor unit 205. Note that the reflection from the front lens 201 and the second lens 202 shown in FIG. 2 also occurs in the third lens 203 and the rear lens 204, and finally appears as a ghost in the image. Since the reflectance of the lens (201, 202, 203, 204) is as small as several percent or less, a ghost does not appear in an image when the amount of light outside the angle of view is the same as that within the angle of view. However, if the light 208 outside the angle of view is larger than the light 207 within the angle of view, it becomes a ghost and appears in the image. In order to eliminate this ghost in a normal imaging apparatus, measures such as reducing the reflectance of the lens and attaching a hood so that light outside the angle of view does not enter are taken. In contrast, in the present invention, when a ghost occurs, it is determined that the subject exists outside the angle of view, and is used to change the shooting range in the direction in which the subject is present.

  Next, the flow of changing the shooting range when a ghost is detected according to the first embodiment of the present invention will be described in detail with reference to FIG.

  First, an image is acquired from the image sensor unit 103, and development processing is performed by the development processing unit 105 (S301). Subsequently, the detection unit 106 detects whether or not a ghost has occurred in the developed image. (S302) If no ghost is detected, the process is terminated and the flow of FIG. 3 is processed again. (S303) When a ghost is detected, the control unit 107 controls the drive unit 108 to change the shooting direction of the imaging apparatus 101 so that the subject that causes the ghost is reflected in the image sensor.

  Next, the flow for changing the shooting range when the ghost direction is detected according to the first embodiment of the present invention will be described in detail with reference to FIGS.

  First, an image is acquired from the image sensor unit 103, and development processing is performed by the development processing unit 105 (S401). Subsequently, the detection unit 106 detects whether or not a ghost has occurred in the developed image (S402). If no ghost is detected, the process is terminated, and the flow of FIG. 4 is processed again (S403). When a ghost is detected, it is detected in which direction the subject of the imaging apparatus 101 is causing the ghost (S404).

  FIG. 5 is a diagram for explaining a ghost detection method. Reference numeral 501 denotes an image in which a ghost is generated, acquired from the imaging apparatus. Reference images 502, 503, 504, and 505 indicate a reference image when a subject that causes a ghost exists on the left side of the screen, a reference image when a subject that causes a ghost exists on the screen, and a right side of the screen. 6 is a reference image when a subject that causes a ghost exists, and a reference image when a subject that causes a ghost exists at the bottom of the screen. The detection unit 106 compares the image 501 with the image 502, the image 503, the image 504, and the image 505, and detects the direction of the subject of the image 501 from the ghost information of the most similar reference image. In the example of FIG. 5, since the image 501 is similar to the image 502, it is detected that a ghost exists on the left side of the screen. Finally, the control unit 107 controls the drive unit 108 to change the shooting direction of the imaging apparatus 101 toward the direction of the subject detected in S404 (S405).

  Next, a flow for detecting a ghost according to the first embodiment of the present invention and changing the shooting range when the position or brightness of the detected ghost changes will be described in detail with reference to FIGS.

  First, an image is acquired from the image sensor unit 103, and development processing is performed by the development processing unit 105 (S601). Subsequently, the detection unit 106 detects whether or not a ghost has occurred in the developed image (S602). If no ghost is detected, the process is terminated and the flow of FIG. 6 is processed again (S603). When a ghost is detected, an image is acquired again from the image sensor unit 103, and development processing is performed by the development processing unit 105 (S605).

  As in S602, the detection unit 106 detects whether or not a ghost has occurred in the image acquired in S605 (S606). If there is no change in the position or brightness of the ghost detected in S603 and the ghost detected in S606 at the detection unit 106, the process ends, and the flow of FIG. 6 is processed again (S607). When there is a change, the control unit 107 controls the drive unit 108 to change the shooting direction of the imaging apparatus 101 so that the subject that causes the ghost is reflected in the imaging element (S603). This is because the direction of the imaging apparatus 101 is not changed when there is no change in position or brightness because the detected ghost may not be a subject that is truly desired to be captured, such as a street light.

  FIG. 7 shows examples of images with and without a change in position or brightness.

  Images 701 and 703 are images acquired in step S601, and images 702 and 704 are images acquired in step S605, which are examples of cases where there is a change in position or brightness, respectively. When there is no change in the position brightness of the ghost as in the images 701 and 702, the shooting range of the imaging device 101 is not changed. On the other hand, the image 703 is an image acquired in S601, and the image 704 is an image acquired in S605. When there is a change in the ghost position brightness as in the image 701 and the image 702, the shooting range of the imaging apparatus 101 is changed.

  Next, the flow for predicting the movement and changing the shooting range when the ghost position changes after detecting the ghost according to the first embodiment of the present invention will be described in detail with reference to FIGS.

  First, an image is acquired from the image sensor unit 103, and development processing is performed by the development processing unit 105 (S801). Subsequently, the detection unit 106 detects whether a ghost has occurred in the developed image (S802). If no ghost is detected, the process is terminated and the flow of FIG. 6 is processed again (S803). When a ghost is detected, an image is acquired again from the image sensor unit 103, and development processing is performed by the development processing unit 105 (S805).

  As in S802, the detection unit 106 detects whether or not a ghost has occurred in the image acquired in S805 (S806). From the direction of the subject causing the ghost detected in S803 and the direction of the subject causing the ghost detected in S804, the position of the subject in the next frame is further predicted. Based on this prediction, the control unit 107 controls the driving unit 108 to change the shooting direction of the imaging apparatus 101 so that the subject is reflected in the imaging apparatus 101. FIG. 9 is a diagram for predicting the movement of the subject in S807. The shooting range of the t-th frame is 901, the subject causing the ghost is 902, and the image shot by the imaging apparatus 101 is 903. In addition, the shooting range of the t + 1 frame is 904, the subject that causes the ghost is 905, and the image shot by the imaging apparatus 101 is 906. From the image 903 of the t frame and the image 906 of the t + 1 frame, the position of the subject 908 of the t + 2 frame is predicted. In accordance with this prediction, a shooting range change S808 is performed. Note that reference numeral 907 denotes a shooting range of the t + 2 frame. By predicting the movement, the accuracy of capturing the subject within the imaging range of the imaging apparatus 101 is increased.

DESCRIPTION OF SYMBOLS 101 Imaging device, 102 Lens group, 103 Image pick-up element part, 104 CPU part

Claims (7)

An optical unit that captures light in a normal shooting range and light outside the shooting range, an image sensor unit that acquires an optical image formed by the optical unit, and light outside the shooting range is detected from the output of the image sensor unit A detection unit, and a drive unit that changes the normal shooting range by pan, tilt, and zoom operations;
When the detection unit detects light of a predetermined value or more, it is assumed that a subject exists outside the shooting range, and the driving unit is driven so as to capture the subject within the normal shooting range. An imaging device. The imaging apparatus according to claim 1, wherein light outside the imaging range is converted into a ghost by the optical unit to form an optical image. The imaging apparatus according to claim 1, wherein the optical unit captures more light in the normal photographing range than light outside the photographing range.   4. The imaging apparatus according to claim 1, wherein the detection unit detects a direction of light outside the imaging range from an output of the imaging element unit. 5. The imaging apparatus according to claim 4, wherein the driving unit is driven in a direction of a subject detected by the detection unit. When the detection unit detects light and there is a change in the position or brightness of the light existing in the image output from the image sensor unit again, a subject existing outside the shooting range is reflected in the normal shooting range. The imaging apparatus according to any one of claims 1 to 3, wherein the driving unit is driven so as to be depressed. If the detection unit detects light and there is a change in the position of the light that is present in the image output from the image sensor unit again, the change in the position of the light is predicted and the light is present outside the shooting range. The imaging apparatus according to claim 1, wherein the driving unit is driven so that a subject to be photographed is reflected in the normal photographing range.