Abstract:
A surveillance method is utilized in a camera system, wherein the camera system comprises a display device, a controller, a first camera disposed fixedly on a base of the camera system and constantly facing toward a first direction, and at least a second camera disposed on the base and controlled by the controller to rotate around the first camera. The surveillance method comprises the display device displaying a wide-angle image captured by the first camera; the controller receiving at least a directional instruction corresponding to at least a specific part of the wide-angle image; and the controller generating a plurality of control signals to steer the at least a second camera toward at least a second direction according to the at least a directional instruction.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a continuation-in-part application of U.S. application Ser. No. 14/487,108 filed on Sep. 16, 2014. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The present invention relates to a surveillance method and a camera system, and more particularly, to a surveillance method and a camera system capable of monitoring a full view of an environment and providing a high resolution image of a part of the environment. 
         [0004]    2. Description of the Prior Art 
         [0005]    A surveillance system is extensively applied to the public place, such as the train station, the supermarket, the street, etc. A fisheye camera or a pan-tilt-zoom (PTZ) camera is applied to the conventional surveillance system. The fisheye camera is able to capture a wide-angle (wide-range) image of an environment. The PTZ camera is able to be panned, tilted and zoomed in/out to capture a high resolution image of a narrow-range of the environment. However, a capturing orientation of the fisheye camera is fixed and a resolution of the fisheye camera is relatively low. It is difficult for the fisheye camera to provide a clear vision of an object of interest in the environment. In addition, a field of view of the PTZ camera is narrow, compared to the fisheye camera, and thus, the object of interest is usually beyond the field of view of the PTZ camera. Therefore, it is necessary to improve the prior art. 
       SUMMARY OF THE INVENTION 
       [0006]    It is therefore a primary objective of the present invention to provide a surveillance method and a camera system capable of monitoring a full view of an environment and providing a high resolution image of a part of the environment, to improve over disadvantages of the prior art. 
         [0007]    An embodiment of the present invention discloses a surveillance method, utilized in a camera system, the camera system comprising a display device, a controller, a first camera disposed fixedly on a base of the camera system and constantly facing toward a first direction, and at least a second camera disposed on the base and controlled by the controller to rotate around the first camera, the surveillance method comprising the display device displaying a wide-angle image captured by the first camera; the controller receiving at least a directional instruction corresponding to at least a specific part of the wide-angle image; and the controller generating a plurality of control signals to steer the at least a second camera toward at least a second direction according to the at least a directional instruction. 
         [0008]    An embodiment of the present invention further discloses a camera system comprising a base; a first camera, disposed on the base, constantly facing toward a first direction, and configured to capture a wide-angle image; at least a second camera, disposed on the base, adjustably facing toward at least a second direction, and controlled to rotate around the first camera; a display device, coupled to the first camera and the at least a second camera, configured to display the wide-angle image; and a controller, coupled to the display device, the first camera and the at least a second camera, configured to generate a plurality of control signals to steer the at least a second camera toward at least a second direction according to at least a directional instruction. 
         [0009]    An embodiment of the present invention further discloses a surveillance method, utilized in a camera system, the camera system comprising a controller, a first camera disposed fixedly on a base of the camera system and constantly facing toward a first direction, and at least a second camera disposed on the base and controlled to rotate around the first camera, the surveillance method comprising the first camera capturing a wide-angle image; the controller identifying at least an image object in the wide-angle image, where the at least an image object is corresponding to at least a moving object in an environment; and the controller generating a plurality of control signals to steer the at least a second camera such that the at least a moving object is within at least a field of view of the at least a second camera. 
         [0010]    An embodiment of the present invention further discloses a camera system, comprises a base; a first camera, disposed on the base, constantly facing toward a first direction, and configured to capture a wide-angle image; at least a second camera, disposed on the base, and controlled to rotate around the first camera; and a controller, coupled to the first camera and the at least a second camera, configured to identify at least an image object in the wide-angle image and generate a plurality of control signals to steer the at least a second camera such that at least a moving object is within at least a field of view of the at least a second camera; wherein the at least an image object is corresponding to the at least a moving object in an environment. 
         [0011]    These and other objectives of the present invention will no doubt become obvious to those of ordinary skill in the art after reading the following detailed description of the preferred embodiment that is illustrated in the various figures and drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0012]      FIG. 1  is a functional block diagram of a camera system according to an embodiment of the present invention. 
           [0013]      FIG. 2  is a schematic diagram of a display device according to the embodiment of the present invention. 
           [0014]      FIG. 3  is a structural diagram of the camera system according to the embodiment of the present invention. 
           [0015]      FIG. 4  is a schematic diagram of a surveillance process according to the embodiment of the present invention. 
           [0016]      FIG. 5  is a schematic diagram of a distortion curve. 
           [0017]      FIG. 6  is a schematic diagram of a zooming process according to the embodiment of the present invention. 
           [0018]      FIG. 7  is a schematic diagram of a surveillance process according to the embodiment of the present invention. 
           [0019]      FIG. 8  is a schematic diagram of a zooming process according to the embodiment of the present invention. 
           [0020]      FIG. 9  is a structural diagram of the camera system according to the embodiment of the present invention. 
           [0021]      FIG. 10  is a schematic diagram of a display device according to the embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0022]    Please refer to  FIG. 1  to  FIG. 3 .  FIG. 1  is a functional block diagram of a camera system  10  according to an embodiment of the present invention.  FIG. 2  is a diagram of a display device  22  applied to the camera system  10  according to the embodiment of the present invention.  FIG. 3  is a structural diagram of the camera system  10  according to the embodiment of the present invention. The camera system  10  comprises abase  12 , a first camera  14 , a second camera  16 , a controller  18 , a rotating mechanism  20  and a display device  22 . The first camera  14  may be a camera with a wide-angle lens, such as a fisheye camera. The first camera  14  is disposed on the base  12  and constantly faces toward a first direction D 1 . The first camera  14  is configured to capture a wide-angle image I 1  of an environment. The second camera  16  may be a pan-tilt-zoom (PTZ) camera with high resolution and variable focal length. The second camera  16  is configured to capture an interested image I 2 . The second camera  16  is disposed on the base I 2  by the rotating mechanism  20 , and adjustably faces toward a second direction D 2 . The display device  22  is coupled to the first camera  14  and the second camera  16 . The display device  22  displays the wide-angle image I 1  captured by the first camera  14  and the interested image I 2  captured by the second camera  16 , where the wide-angle image I 1  may be a circular image of the environment. The rotating mechanism  20  may be a slide rail mechanism or a gear mechanism. The controller  18  may be coupled to the first camera  14 , the second camera  16 , the rotating mechanism  20  and the display device  22 . The controller  18  is configured to generate control signals for the rotating mechanism  20  and the second camera  16 , so as to steer the second camera  16 . 
         [0023]    Furthermore, the base  12  includes a central portion  24  and a rotary portion  26 . The central portion  24  may be an upright structure, and the rotary portion  26  may be an annular holder or an arc holder that moves along a track encircling the upright structure. The first camera  14  is disposed on the central portion  24  without rotary/shift movement. The second camera  16  is disposed on the rotary portion  26 , and may encircle around the first camera  14  by revolution of rotary portion  26  round the central portion  24 . Generally, the rotary portion  26  is preferably a tray with a central hole  261 , and the central portion  24  passes through the central hole  261  and is encircled by the rotary portion  26 . 
         [0024]    In an embodiment, the first camera  14  captures the wide-angle image I 1 , and the display device  22  displays the wide-angle image I 1  captured by the first camera  14 . After the user perceives the wide-angle image I 1  through the display device  22 , if the user is interested in a specific part of the wide-angle image I 1  corresponding to an object of interest in the environment, the user may input a directional instruction to the camera system  10 . The controller  18  may generate a pan signal and a tilt signal to the rotating mechanism  20  and the second camera  16 , such that the second camera  16  is steered to capture the interested image I 2  of the object of interest in the environment. 
         [0025]    Operations of the camera system  10  steering the second camera  16  to capture the interested image I 2  of the object of interest in the environment may be referred to  FIG. 4 , which is a schematic diagram of a surveillance process  40  according to an embodiment of the present invention. The surveillance process  40  is executed by the camera system  10 . The surveillance process  40  comprises following steps: 
         [0026]    Step  400 : Start. 
         [0027]    Step  402 : The display device  22  displays the wide-angle image I 1  captured by the first camera  14 . 
         [0028]    Step  404 : The controller  18  receives a directional instruction corresponding to a specific point within the wide-angle image I 1 . 
         [0029]    Step  406 : The controller  18  obtains a Cartesian coordinate (x 1 ,y 1 ) of the specific point within the wide-angle image I 1 . 
         [0030]    Step  408 : The controller  18  transfers the Cartesian coordinate (x 1 ,y 1 ) into a polar coordinate (r 1 ,θ 1 ). 
         [0031]    Step  410 : The controller  18  generates a pan signal PS and a tilt signal TS according to the polar coordinate (r 1 ,θ 1 ) to steer the second camera  16  toward the second direction D 2 . 
         [0032]    Step  412 : End. 
         [0033]    According to the surveillance process  40 , the camera system  10  is able to steer the second camera  16  so as to capture the interested image I 2  of the object of interest in the environment according to the directional instruction. Specifically, in Step  402 , the display device  22  displays the wide-angle image I 1  captured by the first camera  14 , where the wide-angle image I 1  may be a circular image of the environment. In Step  404 , the directional instruction, inputted by the user, may be a mouse click command pointing at the specific point within the wide-angle image I 1  on the display device  22 , where the mouse click command is inputted by the user via a mouse coupled to the display device  22 . The directional instruction may also be a touch command pointing at the specific point within the wide-angle image I 1 , where touch command is inputted via a finger of the user, if the display device  22  is a touch panel with touch sensing capability. 
         [0034]    After the controller  18  receives the directional instruction, in Step  406  and Step  408 , the controller  18  obtains the Cartesian coordinate (x 1 ,y 1 ) of the specific point within the wide-angle image I 1  and transfers the Cartesian coordinate (x 1 ,y 1 ) into the polar coordinate (r 1 ,θ 1 ) by computing r 1 =√{square root over (x 1   2 +y 1   2 )} and θ 1 =tan −1  (x 1 /y 1 ). 
         [0035]    In Step  410 , the controller  18  generates the pan signal PS and the tilt signal TS according to the polar coordinate (r 1 ,θ 1 ) to steer the second camera  16  toward the second direction D 2 . The pan signal represents an angle which the second camera  16  should be rotated with respect to the central portion  24 . The pan signal PS may be generated by computing PS=σ 1 +θ 0 , where θ 0  is a default value. The tilt signal TS represents an angle between the first direction D 1  and the second direction D 2  in a vertical plane. The tilt signal TS may be determined by r 1  of the polar coordinate (r 1 ,θ 1 ) and a distortion curve. The distortion curve represents an amount of distortion caused by the wide-angle lens, and an exemplary distortion curve is illustrated in  FIG. 5 . The tilt signal TS may be generated by computing TS=r 1 /D 1 +r 0 , where D 1  represents an amount of distortion corresponding to and r 0  is a default value. 
         [0036]    After the pan signal PS and the tilt signal TS are generated, the pan signal PS may be delivered to the rotating mechanism  20  and the tilt signal TS may be delivered to the second camera  16 , such that the second camera  16  is steered toward the second direction D 2  to capture the interested image I 2  of the object of interest in the environment. 
         [0037]    Notably, the user is not limited to the mouse click command or the touch command pointing at the specific point within the wide-angle image I 1 . The user may select a specific rectangle via a mouse within the wide-angle image I 1  displayed on the display device  22 . The controller  18  may interpret a relative location of the rectangular zone within the wide-angle image I 1  selected by the user as the direction instruction. Meanwhile, the controller  18  may also interpret a size of the specific rectangle as a zooming instruction. According to the zooming instruction, the controller  18  may generate a zoom signal for the second camera  16 . The second camera  16  may adjust a focal length thereof, such that a field of view (FOV) of the second camera  16  is corresponding to the specific rectangle within the wide-angle image I 1 , i.e., the interested image I 2  captured by the second camera  16  represents a high resolution image corresponding to the specific rectangle. 
         [0038]    Notably, the user is not limited to select the specific rectangle such that the controller  18  interprets the size of the specific rectangle as the zooming instruction and the second camera  16  zooms in or zooms out accordingly. The user may input a mouse scrolling up/down command via a scrolling wheel of a mouse as the zooming instruction. The user may input an extending gesture or a shrinking gesture on the display device  22 , if the display device  22  has touch sensing capability. Operations of the camera system  10  controlling the second camera  16  to zoom in or zoom out can be summarized as a zooming process  60 , which is illustrated in  FIG. 6 . The zooming process  60  is executed by the camera system  10 . The zooming process  60  comprises following steps: 
         [0039]    Step  600 : Start. 
         [0040]    Step  602 : The controller  18  obtains the zooming instruction. 
         [0041]    Step  604 : The controller  18  generates a zoom signal according to the zooming instruction. 
         [0042]    Step  606 : The second camera  16  zooms in or zooms out according to the zoom signal. 
         [0043]    Step  608 : End. 
         [0044]    Detail operations of the zooming process  60  may be referred to the paragraph stated in the above, which is not narrated herein. According to the zooming process  60 , the interested image I 2  captured by the second camera  16  would be a clear and high resolution vision of the object of interest in the environment. 
         [0045]    Furthermore, in another embodiment, the camera system  10  may track a moving object in the environment. Operations of the camera system  10  tracking the moving object in the environment may be referred to  FIG. 7 , which is a schematic diagram of a surveillance process  70  according to an embodiment of the present invention. The surveillance process  70  is executed by the camera system  50 . The surveillance process  70  comprises following steps: 
         [0046]    Step  700 : Start. 
         [0047]    Step  702 : The first camera  14  captures the wide-angle image 
         [0048]    Step  704 : The controller  18  identifies an image object OBJ in the wide-angle image I 1 , wherein the image object OBJ in the wide-angle image I 1  is corresponding to a moving object OBm in the environment. 
         [0049]    Step  706 : The controller  18  obtains a Cartesian coordinate (x 2 ,y 2 ) of the image object OBJ. 
         [0050]    Step  708 : The controller  18  transfers the Cartesian coordinate (x 2 ,y 2 ) into a polar coordinate (r 2 ,θ 2 ). 
         [0051]    Step  710 : The controller  18  generates the pan signal PS and the tilt signal TS according to the polar coordinate (r 2 ,θ 2 ) to steer the second camera  16  such that an image of the moving object OBm captured by the second camera  16  is at a center of the interested image I 2 . 
         [0052]    Step  712 : End. 
         [0053]    According to the surveillance process  70 , the camera system  10  is able to steer the second camera  16  to track the moving object OBm in the environment. Specifically, in Step  702 , the image object OBJ may be identified by the controller  18  by an object recognition technique. The object recognition technique is known by those skilled in the art and not narrated herein. In Step  704 , the Cartesian coordinate (x 2 ,y 2 ) of the image object OBJ is a representative of the image object OBJ, e.g., the Cartesian coordinate (x 2 ,y 2 ) may be a Cartesian coordinate of a center of the image object OBJ. 
         [0054]    In Step  710 , the controller  18  generates the pan signal PS and the tilt signal TS, so as to steer the second camera  16  such that the image of the moving object OBm captured by the second camera  16  is substantially at the center of the interested image I 2 . In other words, the controller  18  generates the pan signal PS and the tilt signal TS to steer the second camera  16  such that the moving object OBm is within the FOV of the second camera  16  and substantially at a center of the FOV of the second camera  16 . The rest steps of the surveillance process  70  are similar to the surveillance process  40 , which may be referred to the paragraph stated in the above and not narrated herein. 
         [0055]    Furthermore, if the moving object OBm is substantially at the center of the FOV of the second camera  16  but a part of the moving object OBm is out of the FOV of the second camera  16 , the camera system  10  may generate a zooming signal to control the second camera  16  to zoom out, so as to capture the image of the moving object OBm entirely. In addition, the camera system  10  may generate the zooming signal to control the second camera  16  to zoom in or zoom out, such that a size of the image of the moving object OBm is substantially kept as a specific portion of the interested image I 2 , where the specific portion may be specified by system requirements or by the user. Operations of the camera system  10  controlling the second camera  16  to zoom in or zoom out to track the moving object OBm can be summarized as a zooming process  80 , which is illustrated in  FIG. 8 . The zooming process  80  is executed by the camera system  10 . The zooming process  80  comprises following steps: 
         [0056]    Step  800 : Start. 
         [0057]    Step  802 : The controller  18  obtains the zooming instruction. 
         [0058]    Step  804 : The controller  18  generates a zoom signal according to the zooming instruction. 
         [0059]    Step  806 : The second camera  16  zooms in or zooms out according to the zoom signal, such that the moving object OBm is within the FOV of the second camera  16 . 
         [0060]    Step  808 : End. 
         [0061]    The zooming process  80  is similar to the zooming process  60 , and detail operations of the zooming process  80  may be referred to the paragraph stated in the above, which is not narrated herein. According to the zooming process  80 , the focal length of the second camera  16  is adjusted according to the zoom signal, such that the moving object OBm is within the FOV of the second camera  16 . 
         [0062]    Notably, the embodiments stated in the above are utilized for illustrating the concept of the present invention. Those skilled in the art may make modifications and alternations accordingly, and not limited herein. For example, the rotating mechanism  20  is not limited to be the slide rail mechanism or the gear mechanism. The rotating mechanism  20  may be any mechanical mechanism capable of stably rotating the second camera  16 , which conforms to the scope of the present invention. In addition, the wide-angle image I 1  captured by the first camera  14  is not limited to be the circular image. The wide-angle image I 1  may also be a 360° panorama image. Notably, when the wide-angle image I 1  is the 360° panorama image, the controller  18  may obtain the polar coordinate (r 1 ,θ 1 ) of the specific point directly, i.e., there is no need for the controller  18  to transform the Cartesian coordinate into the polar coordinate, which conforms to the scope of the present invention. 
         [0063]    Furthermore, the camera system of the present invention may comprise a plurality of second cameras. For example, please refer to  FIGS. 9 and 10 .  FIG. 9  is a structural diagram of the camera system  90  according to the embodiment of the present invention.  FIG. 10  is a diagram of the display device  22  applied to the camera system  90  according to the embodiment of the present invention. The camera system  90  is similar to the camera system  10 , and thus, same components are denoted by the same symbols. Different from the camera system  10 , the camera system  90  comprises second cameras  16   —   a ,  16   —   b  and rotary portions  26   —   a ,  26   —   b . The second cameras  16   —   a ,  16   —   b  are configured to capture interested image I 2   —   a , I 2   —   b . The camera system  90  may obtain two different directional instructions and two different zooming instructions corresponding to the second cameras  16   —   a ,  16   —   b , respectively. In addition, the camera system  90  may also be able to track two different moving objects by the second cameras  16   —   a ,  16   —   b , respectively. Detail operations are similar to the surveillance processes  40 ,  70  and the zooming processes  60 ,  80 , which are not narrated herein. Notably, in  FIG. 10 , the wide-angle image I 1  herein is a 360° panorama image, which may be obtained by applying a de-wrapping algorithm on a circular image captured by the first camera  14  as the fisheye camera. The de-wrapping algorithm is known by those skilled in the art, which are not narrated herein. 
         [0064]    In summary, the camera system of the present invention is able to monitor a full view of an environment via the first camera and to provide high resolution images of interest objects or moving objects of the environment via the second cameras as well. 
         [0065]    Those skilled in the art will readily observe that numerous modifications and alterations of the device and method may be made while retaining the teachings of the invention. Accordingly, the above disclosure should be construed as limited only by the metes and bounds of the appended claims.