Patent Publication Number: US-2017359507-A1

Title: Method of configuring and adjusting frame coverage for rotatable camera

Description:
FIELD OF THE INVENTION 
     The present invention is related to a method of configuring and adjusting and more particularly related to a method of configuring and adjusting frame coverage for a rotatable camera. 
     BACKGROUND OF THE DISCLOSURE 
     In current monitoring and shooting techniques, a rotatable camera with adjustable frame coverage is available. Specifically, when a user discovers a stranger in a monitoring screen, a rotatable camera can be operated manually to change the orientation of the camera shot and to change the frame coverage, so as to conduct monitoring to the position of the stranger. 
     In addition, such rotatable camera may have an inspection mode. Under inspection mode, the rotatable camera may automatically rotate the camera shot along the default path of tour of inspection (such as the initial position, 0°, and the turning position, 135°) to change the frame coverage continuously, so as to conduct a tour of inspection among fixed points. 
     Although such rotatable camera may change the frame coverage automatically, however, the rotatable camera can only conduct a tour of inspection among fixed points and does not actively detect the position of a stranger and monitoring it. 
     Also, a user is not able to change the tour of inspecting path of the rotatable camera at will as desired. 
     SUMMARY OF THE INVENTION 
     A major object of the invention is to provide a method of configuring and adjusting frame coverage of a rotatable camera by automatically changing the frame coverage of the rotatable camera in real time according to a detection result via easy settings. 
     To achieve the above object, the invention provides a method of configuring and adjusting frame coverage. The method comprises following steps: a) controlling a rotatable camera to shoot a monitoring environment with different angles to generate a plurality of region images; b) combining the region images into a panoramic image; c) receiving an image-selecting operation for selecting a monitoring place from the monitoring environment among the panoramic image among; d) retrieving a rotating angle information corresponding to the selected monitoring place;) corresponding the rotating angle information to a triggering condition; and f) when determining the satisfaction of the trigger condition, controlling the rotatable camera to rotate according to the rotating angle information, so that a current frame coverage of the rotatable camera comprising the monitoring place. 
     The invention effectively makes the settings of the frame coverage more intuitive by using the panoramic image to select a monitoring place. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an architecture diagram of a rotatable camera of the first embodiment in the invention. 
         FIG. 2  is a flow chart of the method of configuring and adjusting frame coverage for a rotatable camera of the first embodiment in the invention. 
         FIG. 3A  is a first flow diagram of the method of configuring and adjusting frame coverage of the rotatable camera of the second embodiment in the invention. 
         FIG. 3B  is a second flow chart of the method of configuring and adjusting frame coverage of the rotatable camera of the second embodiment of the invention. 
         FIG. 4  is a schematic diagram of a setting of the rotatable camera in the invention. 
         FIG. 5  is a schematic diagram of the panoramic image in the invention. 
         FIG. 6  is a schematic diagram of a setting of the frame coverage in the invention. 
         FIG. 7  is a schematic diagram of a calculation of the rotating angle information in the invention. 
     
    
    
     DETAILED DESCRIPTION OF REPRESENTATIVE EMBODIMENTS 
     A preferred embodiment in the invention with drawings will be illustrated in details in the following. 
     Please refer to  FIG. 1 .  FIG. 1  is an architecture diagram of the rotatable camera of the first embodiment in the invention. As shown in the figure, the rotatable camera  1  of the embodiment mainly includes a shooting module  100 , a rotating module  102 , a detecting module  104 , a network module  106 , a memory module  108 , and a processing module  110  electrically connected to the above mentioned elements. Preferably, the rotatable camera  1  is a Pan-Tile (PT) camera or a Pan-Tile-Zoom (PTZ) camera. 
     The shooting module  100  is configured to shoot a monitoring environment, and includes a camera shot and an image sensor. Preferably, the shooting module  100  further includes a zooming module. The zooming module may receive a control from the processing module  110  to change the focal length, such as zoom in or zoom out. 
     The rotating module  102  receives a control from the processing module  110  to change the orientation of the camera shot of the shooting module  100 , such that the shooting module  100  may shoot different regions of the monitoring environment. Preferably, the rotating module  102  includes a rotating platform and an inclined mechanism. The rotating module  102  may receive a control from the processing module  110  to rotate horizontally the rotating platform to change horizontally the orientation of the camera shot, or to incline vertically the inclined mechanism to vertically change the orientation of the camera shot. 
     The detecting module  104  connects at least one sensor  20 , and may receive a sensing signal from the sensor  20  (such as a triggering signal, a brightness signal, a temperature signal, an ultrasonic reflecting signal, or an infrared reflecting signal). The sensor  20  may be a doorbell triggering device, a brightness sensor, a temperature sensor, a motion-detecting sensor (such as infrared sensor (PIR sensor) or ultrasonic sensor), a sound sensor or any combination mentioned above. 
     The network module  106  connects to a network  22  (such as a local area network or the internet), and may connect to a user device  24  or a server  26  via the network  22 . Preferably, the network module  106  connects to the network  22  via a gateway device and/or a router (not shown in the figure). Preferably, the network module  106  is a wireless network module complying with the IEEE 802.11 standard, but should not be limited herein. The memory module  108  is configured to store data. 
     The processing module  110  is configured to control the rotatable camera  1 . Preferably, the processing module  110  may control the rotatable camera  1  to switch between the setting mode and a monitoring mode. Also, under the setting mode, the processing module may execute a function of setting the frame coverage; under the monitoring mode, the processing module  110  may execute a function of adjusting the frame coverage (as will be illustrated in details later). 
     In another embodiment of the invention, the network module  106  is connected to a user device  24  via a peer-to-peer connection. Specifically, the memory module  108  stores the newest connecting information of the network module  106  (such as a device ID, a MAC address, and an IP address), and the processing module  110  can transmit the newest connecting information to the server  26  by the network module  106  by timed or when updating the connecting information (such as the router redistributing the network address). 
     Also, the user device  24  stores a camera application program (not shown in the figure) configured to interact with the rotatable camera  1 . The user device  24  can retrieve the newest connecting information of the rotatable camera  1  from the server  26  after executing the camera application program, and constructing a peer-to-peer connection with the network module  106  of the rotatable camera  1  according to the retrieved connecting information. 
     Thereby, even though the rotatable camera  1  adopts the Dynamic IP address, the user device  24  can also connect to the rotatable camera  1  from exterior networks. 
     In another embodiment of the invention, the rotatable camera  1  further has a gateway function. Specifically, the sensor  20  is a peer-to-peer (P2P) device. The rotatable camera  1  can construct a peer-to-peer connection with the sensor  20  via the detecting module  104 . Next, the sensor  20  may receive a control from the rotatable camera  1  (for example, a user can operate the user device  24  to be connected to the rotatable camera  1 , and controls the sensor  20  via the rotatable camera  1 ) via the constructed peer-to-peer connection, or transmits a sensing signal to the rotatable camera  1 . 
     In another embodiment of the invention, the memory module  108  further stores a plurality of webpages. The processing module  110  can provide a connecting service of the webpages via the internet module  106  when detecting the connecting demand from the user device  24 , wherein the webpages are configured to provide related information for the sensor  20  or related information for the rotatable camera  1 , or receiving an operation from a user (such as an image-selecting operation, a sensor-selecting operation, or a zooming setting operation which will be mentioned later). 
     In another embodiment of the invention, the user device  24  can construct a network connection(such as the peer-to-peer connection mentioned before) with the rotatable camera  1  after executing the camera application program, and conducts interactions with the rotatable camera  1  via the constructed network connection. 
     Specifically, the user device  24  can retrieve the related information of the sensor  20  or the related information of the camera  1  from the automatic camera  1  via the network connection after executing the camera application program. Or, the user device  24  can show a graphical user interface (GUI) after executing the camera application program, and receiving the operation(such as an image-selecting operation, a sensor-selecting operation, or a zooming setting operation mentioned later) from the user via the GUI, and transmits the received operation from the user to the rotatable camera  1  (such as generating a corresponding command according to the operation of the user, and transmitting the command to the rotatable camera  1 ). 
     Next, the method of configuring and adjusting frame coverage for a rotatable camera of each embodiment in the invention is illustrated herein. It is worth mentioning that, the method of configuring and adjusting frame coverage for a rotatable camera is implemented by using the rotatable camera shown in  FIG. 1 . Furthermore, the memory module  108  further stores a computer program  1080 . The computer program  1080  includes computer-executable codes. After the processing module  110  executing the computer program  1080 , each step of the method of configuring and adjusting frame coverage for a rotatable camera of each embodiment in the invention can be executed. 
     Continue to refer to  FIG. 2 .  FIG. 2  is a flow chart of the method of configuring and adjusting frame coverage for a rotatable camera of the first embodiment in the invention. The method of configuring and adjusting frame coverage for a rotatable camera of the embodiment includes the following steps. 
     Step S 10 : the processing module  110  controls the rotatable camera  1  entering a setting mode. Preferably, the processing module  110  controls the rotatable camera  1  to enter the setting mode when receiving a command to entering the setting mode from the user device  24  via the network module  106 . 
     Step S 12 : the processing module  110  controls the rotatable camera  1  to respectively shoot different regions of the monitoring environment by different angles to generate a plurality of region images corresponding respectively to different regions. 
     For example, the processing module  110  can control the rotating platform of the rotating module  102  to rotate clockwise for 120° to link up the camera shot of the shooting module  100  changing the orientation continuously, and shoots a plurality of region images during the process of rotation. 
     Step S 14 : the processing module  110  combines the shot plurality of region images into a panoramic image. Preferably, the processing module  110  combines the plurality of region images in sequence according to the sequence of shooting of the plurality of region images. Thereby, the panoramic image after completing the combination can reveal the distribution of the plurality of regions of the monitoring environment. 
     Next, the processing module  110  can transmit to and show the panoramic image on the user device  24  via the network module  106   
     Step S 16 : the processing module  110  receives the image-selecting operation by a user via the network module  106  and the user device  24 . The image-selecting operation selects images situated at the monitoring places of the monitoring environment among the showed panoramic images. 
     Preferably, the user device  24  can generate a corresponded image-selecting command according to the received image-selecting operation after receiving the image-selecting operation, and transmits to the rotatable camera  1 . Thereby, the processing module  110  of the rotatable camera  1  can know the selected image by the user via the received image-selecting command. 
     Step S 18 : the processing module  110  retrieves the rotating angle information corresponding to the selected image (i.e. the monitoring place). 
     Preferably, the processing module  110  calculates the rotating angle information corresponding to the selected image according to the position corresponding to the selected image (i.e. the monitoring place selected by the user) among the panoramic image and the predetermined angle (including the horizontal rotating angle and the vertical inclined angle) in the step S 12 . 
     Step S 20 : the processing module  110  corresponds the retrieved rotating angle information to the triggering condition. Specifically, the processing module  110  revives a user operation via the network module  106  and the user device  24 , and corresponds the retrieved rotating angle information to the specific triggering condition (such as a triggered doorbell, an opened door or window, a temperature higher than a predetermined temperature, a variation of brightness larger than the predetermined variation of brightness, or the coming of the predetermined time) to complete the setting according to the received operation. 
     Step S 22 : the processing module  110  controls the rotatable camera  1  entering the monitoring mode. Preferably, the processing module  110  controls the rotatable camera  1  to enter the monitoring mode when receiving the command of entering the monitoring mode from the user device  24  via the network module  106 . 
     Under the monitoring mode, the rotatable camera  1  can continuously shoot the particular region of the monitoring environment (such as a doorway), or shoots a plurality of regions in turns along the predetermined tour of inspecting path. 
     Step S 24 : the processing module  110  determines if the triggering condition is satisfied during the monitoring process. If the processing module  110  determines the satisfaction of the triggering condition, executing the step S 26 ; if not, executing again the step S 24 . 
     Step S 26 : when the processing module  110  determines the satisfaction of the triggering condition, retrieves a rotating angle information corresponding to the satisfied triggering condition, and controls the rotatable camera  1  to rotate according to the retrieved rotating angle information, such that the current frame coverage of the rotatable camera  1  covers the monitoring place (i.e. the monitoring place selected in step S 16 ). 
     The invention can effectively let the settings of the frame coverage more intuitive by using the panoramic image to provide users of selecting monitoring places, so as to effectively enhance user experiences. 
     Also, the invention automatically adjusts the frame coverage according to the satisfied triggering condition, which can effectively conduct monitoring to the particular monitoring place automatically when the event happens. 
     It is worth mentioned that, although in the embodiment the rotatable camera  1  shoots a particular region or a plurality of regions under the monitoring mode, but should not be limited herein. 
     In another embodiment of the invention, when the rotatable camera  1  determines no triggering condition is satisfied under the monitoring mode, the shooting will not be conducted, and only when the triggering condition is satisfied will it adjust the frame coverage automatically and shooting the monitoring place. 
     Thereby, the invention can effectively reduce the time length of shooting videos and further reducing the amount of data of the generated monitoring videos via stopping recording when there is no event detected (i.e. not any triggering condition is satisfied), and starting recording when an event is detected. 
     Please also refer to  FIG. 3A  and  FIG. 3B .  FIG. 3A  is a flow chart of the method of configuring and adjusting frame coverage of the first rotatable camera of the second embodiment in the invention.  FIG. 3B  is a flow chart of the method of configuring and adjusting frame coverage of the second rotatable camera of the second embodiment of the invention. In the embodiment, the triggering condition is the trigger of the sensor  20 . The method of configuring and adjusting frame coverage for a rotatable camera of the embodiment includes the following steps. 
     Step S 300 : the processing module  110  controls the rotatable camera  1  entering the setting mode. 
     Step S 302 : the processing module  110  controls the rotatable camera  1  to shoot one of the plurality of regions of the monitoring environment at the initial angle (such as 0°), and generating a region image. 
     Step S 304 : the processing module  110  controls the rotatable module  102  to rotate a predetermined shooting rotating angle, and controls the shooting module  100  to shoot another region of the monitoring environment after rotation, so as to generate another region image. 
     Preferably, the shooting rotating angle is not larger than the viewable angle of the frame coverage of the shooting module  100 . Thereby, the edge of the two region images of the shooting angle spacing the shooting rotating angle will be continuous or the same, and will be beneficial to the subsequent combining process. 
     Step S 306 : the processing module  110  determines if the rotating module  102  already rotates the predetermined rotating angle, wherein the shooting rotating angle is less than the predetermined rotating angle. 
     Preferably, the predetermined rotating angle is the maximum rotating angle in which the rotating module  102  can rotate (such as the maximum angle the rotating platform can rotate or the maximum angle the inclined mechanism can incline). Or, the predetermined rotating angle is set by a user according to the size of the monitoring environment and the viewable angle of the frame coverage of the shooting module  100 . 
     If the processing module  110  determines the rotating module  102  already rotates the predetermined rotating angle, then executing the step S 308 . Otherwise, executing again the step S 304 , so as to shoot another region. 
     Step S 308 : the processing module  110  combines the images of the plurality of regions into a panoramic image. Specifically, the processing module  110  conducts combinations in sequence on the images with continuous edges or the same plurality of regions, so as to obtain a panoramic image corresponding to the complete monitoring environment. 
     Step S 310 : the processing module  110  receives a plurality of image-selecting operations via the user device  24 , wherein each image-selecting operation respectively selects different monitoring places in the monitoring environment among the panoramic image shown on the user device  24 . 
     Step S 312 : the processing module  110  divides the panoramic image into a plurality of image blocks. 
     Step S 312 : the processing module  110  calculates rotating angle information corresponding to each image block. 
     Preferably, the processing module  110  calculates rotating angle information corresponding to each image block according to the predetermined rotating angle, the viewable angle of the panoramic image, and positions corresponding to each image block among the panoramic image. 
     It is worth mentioning that, the viewable angle of an image is the range of the viewing angle which can be demonstrated in the image. For example, if the viewable angle of the image is 120°, the field of view which can be demonstrated in the image is to regard the photographer (such as the rotatable camera  1 ) as the center of the circle, and with the range of 120° as total. 
     Step S 316 : the processing module  110  respectively identifies image blocks comprising each monitoring place selected by the user according to the plurality of image-selecting operations, and respectively calculates the rotating angle information corresponding to each image block, wherein the rotating angle information includes a horizontal rotating angle and a vertical inclined angle. 
     It is worth mentioning that, although in the embodiment, the step S 312 , S 314  are executed after the step S 310 , but it can also be revised to execute the step S 312 , S 314  before the step S 310 . For example, the processing module  110  can first divide the panoramic image in to a plurality of regions and calculates the corresponding rotating angle information, and then receives a plurality of image-selecting operation. That is to say, how the processing module  110  divides the plurality of image blocks is irrelevant to the plurality of image-selecting operations. 
     Step S 318 : the processing module  110  detects and connects the sensor  20  set up in the monitoring environment via a detecting module  20 . Preferably, the processing module  110  scans the sensor  20  in the monitoring environment using a wireless radio frequency (RF) via the detecting module  20 , and constructs a connection (such as a peer-to-peer connection) to the scanned sensor  20 . 
     Step S 320 : the processing module  110  receives the plurality of sensor-selecting operations of the user via the network module  106  and the user device  24 . Preferably, the processing module  110  can transmit an identifying information of the detected sensor  20  to show on the user device  24 , or shows the identifying information of the detected sensor  20  on a webpage provided by the network module  106 , so as to provide the user to select the plurality of sensors  20  via operating the camera application program or the webpage. 
     Step S 322 : the processing module  110  receives the zooming setting operations from the user via network module  106  and the user device  24 . 
     Preferably, the rotating angle information further includes a set of zooming value. The zooming setting operation corresponds to the particular image-selecting operation, and can change the size of frame coverage of the shooting module  100 . Also, after retrieving the corresponding rotating angle information (i.e. the step S 316 ), the processing module  110  can operate and set the zooming value of the rotating angle information according to the zooming setting, such that the shooting module  100  automatically change the focal length when shooting the region corresponding to the rotating angle information. 
     It is worth mentioning that, although in the embodiment, the step S 318  is executed after the step S 316 , it can also be revised to execute the step S 318 , S 320 , S 322  before the step S 316 . For example, the processing module  110  can simultaneously execute the step S 318  while shooting the region image (i.e. the steps S 302 -S 306 ), and simultaneously executes the step S 320 , S 322  while executing the step S 310 , so as to simultaneously receive the image-selecting operation, the sensor-selecting operation, and the zooming setting operation. 
     Step S 324 : the processing module  110  corresponds respectively the retrieved plurality of rotating angle information to the selected plurality of sensors  20 . 
     Step S 326 : the processing module  110  controls the rotatable camera  1  into the monitoring mode. 
     Step S 328 : the processing module  110  determines if there are plurality of sensors  20  been triggered at the same time (i.e. the plurality of triggering conditions are satisfied). 
     Preferably, the processing module  110  determines if the plurality of sensors  20  been triggered according to the plurality of sensing signals emitted by the plurality of sensors  20 . 
     If the processing module  110  determines the plurality of sensors  20  been triggered simultaneously, then executes the step S 330 . Otherwise, the processing module  110  executes the step S 332 . 
     Step S 330 : the processing module  110  retrieves the plurality of rotating angle information corresponding to the triggered plurality of sensor  20 , controls the rotatable camera to shoot the plurality of monitoring places simultaneously or in sequence according to the plurality of rotating angle information. 
     Preferably, if the processing module  110  determines the plurality of monitoring places are close and can be covered in the same frame coverage by the rotatable camera  1  simultaneously, the processing module  110  calculates a set of calibrated rotating angle information (such as calculating the middle value or the average value of the plurality of rotating angle information) according to the retrieved plurality of rotating angle information, and controls the rotatable camera  1  to rotate according to the calibrated rotating angle information, such that the current frame coverage of the rotatable camera  1  covers the corresponding plurality of monitoring places simultaneously. 
     Specifically, the calibrated rotating angle information can include a calibrated rotating angle, a calibrated inclined angle, and a calibrated zooming value. The processing module  110  calculates the calibrated rotating angle, the calibrated inclined angle, and the calibrated zooming angle according to the rotating angle, the inclined angle, and the calibrated zooming value of the plurality of rotating angle information. 
     Also, the processing module  110  controls the camera shot of the shooting module  100  of the rotatable camera  1  rotating horizontally the calibrated rotating angle, inclining vertically the calibrated inclined angle, and adjusting the focal length of the rotatable camera  1  according to the calibrated zooming value. 
     If the processing module  110  determines the distances between the plurality of monitoring places are too far, and cannot be covered simultaneously in the same frame coverage of the rotatable camera  1 , the processing module  110  calculates the shooting path according to the retrieved plurality of rotating angle information, and controls the rotatable camera  1  to shoot the plurality of monitoring places in turn along the shooting path. 
     Specifically, the processing module  110  controls the camera shot of the shooting module  100  of the rotatable camera  1  to rotate horizontally the rotating angles of each rotating angle information in order; to incline vertically the inclined angles of each rotating angle information in order; and to adjust the focal length of the rotatable camera  1  in order according to the zooming values of each rotating angle information, so as to shoot the plurality of monitoring places in order. 
     Step S 332 : the processing module  110  determines if there is only a single sensor  20  been triggered at the same time (i.e. the single triggered condition is satisfied). 
     If the processing module  110  determines there is only a single sensor  20  been triggered, executing the step S 334 . Otherwise, executing the step S 328  again. 
     Step S 334 : the processing module  110  retrieves rotating angle information corresponding to the sensor  20 , and then controls the camera shot of the shooting module  100  of the rotatable camera  1  rotating horizontally with a retrieved rotating angle from the rotating angle information, and inclines vertically a retrieved inclined angle from the retrieved rotating angle information. 
     Step S 336 : the processing module  110  can further adjust the focal length of the rotatable camera  1  according to the retrieved zooming value from the rotating information when determining the retrieved rotating angle information including a zooming value, so as to enlarge the image of the monitoring place or to increase the frame coverage. 
     Please refer to  FIG. 4  and  FIG. 6 .  FIG. 4  is a schematic diagram of a setting of the rotatable camera in the invention.  FIG. 5  is a schematic diagram of the panoramic image in the invention.  FIG. 6  is a schematic diagram of a setting of the frame coverage in the invention configured to exemplify the application situations of the method of configuring and adjusting frame coverage for a rotatable camera. 
     As shown in  FIG. 4 . In this example, a plurality of sensors  200 - 206  are respectively an infrared sensor, a door magnetic sensor, a doorbell, and an ultrasonic senor, respectively installed at different monitoring places of the monitoring environment. The rotational camera  1  is installed above the front door to monitor the whole monitoring environment. 
     As shown in  FIG. 5 , the rotatable camera  1  shoots respectively a plurality of regions of the monitoring environment with different rotating angles under the setting mode, so as to generate a plurality of region images  30 - 34 . Next, the rotatable camera  1  can conduct a pre-image processing (such as distortion compensation, an image straightening, or a cropping) to the region images  30 - 34 , and then combines the processed region images  30 - 34  into a panoramic image  3 . 
     In addition, the rotatable camera  1  can further detect the plurality of sensors  200 - 206  installed in the monitoring environment under the setting mode, constructing a connection to the detected sensor and retrieving the identifying information. 
     Next, the rotatable camera  1  transmits the identifying information of the panoramic image  3  and the identifying information of the plurality of sensors  200 - 206  to the user device  24 . 
     As shown in  FIG. 6 , the user device  24  can show a plurality of selections  40 - 46  on a screen  240  according to the received plurality of identifying information, wherein the plurality of selections  40 - 46  can show respectively the identifying information of the corresponding plurality of sensors  200 - 206  (for example, the selection  40  shows the identifying information of the sensor  204  “doorbell”; the selection  42  shows the identifying information of the sensor  200  “infrared sensor”; the selection  44  shows the identifying information of the sensor  205  “ultrasonic sensor”; the selection  46  shows the identifying information of the sensor  202  “door magnetic sensor”). Also, the user device  24  can also shows the panoramic image  3  on the screen  240  in a clickable way. 
     Next, a user can enter an image-selecting operation, a sensor-selecting operation and/or a zooming setting operation via the user device  24 . Specifically, a user can select a monitoring place  60  (image-selecting operation), and then selects the selection  44  (sensor-selecting operation), so as to correspond the rotating angle information (corresponding to the monitoring place  60 ) to the sensor  206 . A user can also select a monitoring place  62 , and then selects the selection  40 , so as to correspond the rotating angle information (corresponding to the monitoring place  60 ) to the sensor  206 . A user can also select a monitoring place  66 , and then selects the selection  42 , so as to correspond the rotating angle information (corresponding to the monitoring place  66 ) to the sensor  200 . A user can also select a monitoring place  64 , and then selects the selection  46 , so as to correspond the rotating angle information (corresponding to the monitoring place  60 ) to the sensor  202 . 
     In addition, since the monitoring place  64  is farther to the rotatable camera  1  in distance, a user can also further set a zooming value to be 50 mm (zooming setting operation), such that the rotatable camera  1  can automatically switch to a longer focal length when shooting the monitoring place  64 , so as to obtain an enlarged image of the monitoring place  64 . 
     Thereby, when any one of the sensors  200 - 206  is triggered (such as the detection of a person by the infrared sensor or the ultrasonic sensor, a pressing of the doorbell, or an opening of the gate), the rotatable camera  1  can automatically change the frame coverage to shoot the corresponding monitoring places  60 - 66 . 
     Also, a user only needs to click the monitoring places  60 - 66  among the panoramic image  3 , and can simply complete the setting of the frame coverage of the rotatable camera  1 , thus the degree of difficulty in settings can be effectively reduced. 
     Continue to refer to  FIG. 5  and  FIG. 7  simultaneously.  FIG. 7  is a schematic diagram of a calculation of the rotating angle information in the invention configured to exemplify the retrieving ways for the rotating angle information. 
     In the example, the movable angle (i.e. the predetermined rotating angle) of the rotatable camera  1  is 240° horizontally and 90° vertically. Also, the rotatable camera  1  shoots the region image  30  when rotating 40° horizontally and inclining 20° vertically; shoots the region image  32  when rotating 120° horizontally and inclining 20° vertically; shoots the region image  34  when rotating 200° horizontally and inclining 20° vertically. 
     The single frame coverage of the rotatable camera  1  (i.e. the viewable angles of each region image  30 - 34 ) is 80° horizontally and 40° vertically. The size of the panoramic image  3  is 4800 pixels×800 pixels, and the viewable range is 240° horizontally and 40° vertically. 
     As shown in  FIG. 7 , the rotatable camera  1  can divide each region image  30 - 34  respectively into 4 image blocks, so as to divide the panoramic image into 12 image blocks  500 - 522 . 
     Next, the rotatable camera  1  calculates the rotating angle information corresponding to each image blocks  500 - 522 . Specifically, the rotatable camera  1  calculates the rotating angle information corresponding to the frame coverage of the covered image blocks  500 - 522  (such as the frame coverage  70 ,  72 ,  720 ). 
     Preferably, the rotatable camera  1  first views a pixel as a unit to coordinate the panoramic image  3 . Next, the rotatable camera  1  calculates the coordinate of the central point of the particular image blocks; calculates the ratio between the coordinate and the coordinate range of the panoramic image  3 ; and calculates the rotating angle corresponding to the particular image block according to the calculated ratio and the viewable range of the panoramic image  3 . 
     Taking the rotating angle information corresponding to the image block  502  as an example, the rotatable camera  1  calculates the coordinate of the central point of the image block  502  ( 1200 , 600 ); calculates the ratio (1/4, 3/4) between the coordinate and the size of the panoramic image  3  ( 4800 , 800 ); and then calculates the corresponding rotating angle information (horizontal 60°, vertical 30°) according to the calculated ratio and the viewable range of the panoramic image  3  (horizontal 240°, vertical 40°). Thereby, the rotatable camera  1  can adjust the current frame coverage to cover the frame coverage  70  of the image block  502  via rotating 60° horizontally and inclining 30° vertically. Furthermore, when the user selects the monitoring place  60 , the rotatable camera  1  can identify the monitoring place  60  situated in the image block  502 , and views the rotating angle information corresponding to the image block  502  directly as the rotating angle information of the monitoring place  60 . 
     Taking the rotating angle information corresponding to the image block  508  as an example, the rotatable camera  1  calculates the coordinate of the central point of the image block  508  ( 3600 , 600 ); calculates the ratio (3/4 , 3/4) between the coordinate and the size of the panoramic image  3  ( 4800 , 800 ); and then calculates the corresponding rotating angle information (horizontal 180°, vertical 30°) according to the calculated ratio and the viewable range of the panoramic image  3  (horizontal 240°, vertical 40°). Thereby, the rotatable camera  1  can adjust the current frame coverage to cover the frame coverage  72  of the image block  508  via rotating 180° horizontally and inclining 30° vertically. 
     Furthermore, the rotatable camera  1  can also enhance the focal length according to the zooming value of the rotating angle information, and enlarges the image of the image block  508  via shrinking the frame coverage  72  to be the frame coverage  720 . Thereby, when a user selects the monitoring place  64 , the rotatable camera  1  can identify the monitoring place  64  situated in the image block  508 , and views the rotating angle information corresponding to the image block  508  directly as the rotating angle information of the monitoring place  64 . 
     Although in the example mentioned above, the rotatable camera  1  views the rotating angle information corresponding to the image block directly as the rotating angle information of the monitoring place, but it should not be limited herein. 
     In another embodiment of the invention, the rotatable camera  1  retrieves the coordinate of the monitoring place selected by a user; calculates the ratio between the coordinate and the viewable range of the coordinate of the panoramic image  3 ; and calculates the corresponding rotating angle information according to the calculated ratio and the viewable range of the panoramic image  3 . 
     The examples are only preferred specific embodiments of the invention, and are not thence restrictive to the scope of claims of the invention. Therefore, those who apply equivalent changes incorporating contents from the invention are included in the scope of the invention, as stated herein.