Abstract:
A method for controlling a monitoring camera, and which includes generating a mask image using a first mask color, synthesizing the mask image on a specific region of a camera image captured by the monitoring camera, detecting a brightness value of the camera image, determining a second mask color corresponding to the detected brightness value of the camera image, and changing the first mask color of the mask image synthesized on the camera image to the determined second mask color.

Description:
CROSS REFERENCE TO A RELATED APPLICATION 
       [0001]    This non-provisional application claims priority under 35 U.S.C. §119(a) to Korea Patent Application No. 10-2008-7459 filed in Republic of Korea on Jan. 24, 2008, the entire contents of which are hereby incorporated by reference. 
       BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The present application relates to an apparatus and method for controlling a color of a mask of a monitoring camera. 
         [0004]    2. Description of the Related Art 
         [0005]      FIG. 1  illustrates an example in which a digital video recorder is connected to a plurality of monitoring cameras. In this example, sixteen monitoring cameras are connected to one digital video recorder (DVR). Further, camera images shot by the sixteen monitoring cameras may be written and stored in a hard disk HDD in the digital video recorder, or may be displayed on the screen of a monitor connected to the digital video recorder. 
         [0006]      FIG. 2  illustrates the construction of a general monitoring camera. For example, the monitoring camera includes a zoom lens  10 , a focus lens  11 , an iris  12 , a CCD  13 , an amplifier  14 , a signal processor  15 , a mixer  16 , an interface  17 , a motor driver  18 , a microcomputer  19 , a mask generator  20 , a memory  21 , a keypad  22 , and so on. 
         [0007]    In addition, the microcomputer  19  operatively controls the motor driver  18 , the signal processor  15 , and so on to output a camera image shot in real time to the digital video recorder DVR. Moreover, the microcomputer  19  operatively controls the mask generator  20  to generate and output a mask image of a certain shape and color, and the mixer  16  synthesizes the mask image on a specific region of the camera image, thereby preventing the specific region of the camera image from being visible. That is, the masked region is generally masked or covered to establish some privacy protection or the like from the captured image. 
         [0008]    However, in a general monitoring camera, the color of a mask image synthesized on a specific region of a camera image is generated as a certain color set by a user. Thus, there is the problem that when the camera image is lightened or darkened, it is difficult or impossible to identify the camera image requiring privacy protection. 
         [0009]    Further, there is the problem that even if an object motion occurs within a specific region of a camera image synthesized with a mask image, the user cannot see the corresponding object image and does not even know whether or not an object motion has occurred because the mask image is synthesized. 
       SUMMARY OF THE INVENTION 
       [0010]    Accordingly, one object of the present invention is to address the above-noted and other problems. 
         [0011]    Another object of the present invention is to provide an apparatus and method for controlling the color of a monitoring camera, which synthesizes a mask image on a specific region of a camera image, automatically changes the color of the mask image according to the brightness of the camera image or change the color of the mask image according to an object motion detected from the camera image, and outputs a warning sound or warning message. 
         [0012]    To achieve these and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described herein, the present invention provides in one aspect a method for controlling a monitoring camera, and which includes generating a mask image using a first mask color, synthesizing the mask image on a specific region of a camera image captured by the monitoring camera, detecting a brightness value of the camera image, determining a second mask color corresponding to the detected brightness value of the camera image, and changing the first mask color of the mask image synthesized on the camera image to the determined second mask color. The present invention also provides a corresponding apparatus for controlling a monitoring camera. 
         [0013]    In another aspect, the present invention provides a method for controlling a monitoring camera, and which includes generating a mask image using a first mask color, synthesizing the mask image on a specific region of a camera image captured by the monitoring camera, detecting an object motion from the camera image, and changing the first mask color of the mask image synthesized on the camera image into a second mask color if the detected object motion moves into an area defined by the mask image. The present invention also provides a corresponding apparatus for controlling a monitoring camera. 
         [0014]    Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0015]    The present invention will become more fully understood from the detailed description given herein below and the accompanying drawings, which are given by illustration only, and thus are not limitative of the present invention, and wherein: 
           [0016]      FIG. 1  is an overview illustrating a plurality of general monitoring cameras connected to a digital video recorder; 
           [0017]      FIG. 2  is a block diagram illustrating a general monitoring camera; 
           [0018]      FIG. 3  is a block diagram illustrating a monitoring camera according to an embodiment of the present invention; 
           [0019]      FIG. 4  is a flowchart illustrating a method for controlling a color of a mask of a monitoring camera according to a first embodiment of the present invention; 
           [0020]      FIG. 5  is an overview illustrating changing a color of a mask according to the first embodiment of the present invention; 
           [0021]      FIG. 6  is a flowchart illustrating a method for controlling a color of a mask of a monitoring camera according to a second embodiment of the present invention; 
           [0022]      FIG. 7  is an overview illustrating changing a color of a mask according to the second embodiment of the present invention; 
           [0023]      FIG. 8  is a block diagram illustrating a monitoring camera according to an embodiment of the present invention; 
           [0024]      FIG. 9  is a flowchart illustrating a method for controlling a color of a mask of a monitoring camera according to a third embodiment of the present invention; and 
           [0025]      FIG. 10  is an overview illustrating changing a color of a mask according to the third embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0026]    Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings. 
         [0027]    An apparatus and method for controlling the color of a mask of a monitoring camera according to embodiments of the present invention are applicable to various types of monitoring cameras used to monitor a specific location. 
         [0028]      FIG. 3  is a block diagram illustrating a monitoring camera according to a first embodiment of the present invention. As shown, the monitoring camera includes a zoom lens  30 , a focus lens  31 , an iris  32 , a CCD  33 , an amplifier  34 , a signal processor  35 , a mixer  36 , an interface  37 , a motor driver  38 , a microcomputer  39 , a mask generator  40 , a memory  41 , a keypad  42 , and so on. 
         [0029]    The monitoring camera also includes a detector  43  for detecting the brightness of a camera image or detecting an object motion. For instance, in a first embodiment of the present invention, the detector  43  detects the brightness of a camera image, while in a second embodiment of the present invention, the detector  43  detects an object motion from a camera image. 
         [0030]    Next,  FIG. 4  is a flowchart illustrating a method for controlling the color of a mask of a monitoring camera.  FIG. 3  will also be referred to in this description. As shown in  FIG. 4 , the microcomputer  39  sets a mask color control mode according to a user&#39;s request or the like (S 10 ). 
         [0031]    The detector  43  then receives a camera image signal output through the signal processor  35  to detect a brightness (S 11 ), for example, extracts a luminance component of the camera image signal to detect an average brightness value, and then outputs the average value to the microcomputer  39 . 
         [0032]    Further, the microcomputer  39  retrieves, for example, mask color table information stored and managed in the memory  41  (S 12 ). The mask color table information has the brightness of a camera image and the corresponding optimum mask colors linked with each other as an experimental result value. The mask color table information is also preferably stored in a lookup table format. 
         [0033]    In addition, the microcomputer  39  selects and retrieves a particular mask color corresponding to the brightness of the camera image signal within the mask color table information (S 13 ), and operatively controls the mask generator  40  in accordance with the selected and retrieved mask color (S 14 ). 
         [0034]    For instance, as illustrated in  FIG. 5 , when the brightness of the camera image is changed from a normal brightness to a low brightness, the microcomputer  39  changes the color of the mask image from yellow to red. Then, if the mask color control mode is cleared according to a user&#39;s request or the like (Yes in S 15 ), the microcomputer  39  operatively controls the mask generator  20 , and changes the color of the mask image to a previously set basic color (e.g., yellow) (S 16 ). 
         [0035]      FIG. 6  is a flowchart illustrating a method for controlling a color of a mask of a monitoring camera according to a second embodiment of the present invention.  FIG. 3  will also be referred to in this description. 
         [0036]    As shown in  FIG. 6 , the microcomputer  39  sets, for example, a multi-mask color control mode according to a user&#39;s request or the like (S 30 ). For example, the microcomputer  39  operatively controls the mask generator  40  to synthesize a first mask image of a large size and a second mask image of a small size on a camera image as illustrated in  FIG. 7 . 
         [0037]    The detector  43  then receives a camera image signal output through the signal processor  35  and detects a motion of an object which is moved (S 31 ). For example, a current video frame (n) in which an image signal is processed in real time and a video frame (n- 1 ) in which an image signal has been previously processed are compared with each other to output a region in which an object motion is detected to the microcomputer  39 . 
         [0038]    Further, the microcomputer  39  monitors, for example, as shown in  FIG. 7 , whether or not the region in which the object motion is detected moves into the first mask image, and as the result of monitoring, if it moves into the first mask image (S 32 ), the microcomputer  39  operatively controls the mask generator  40  to change the colors of the first mask image and second mask image to colors different from the previous color (S 33 ). 
         [0039]    Moreover, the microcomputer  39  monitors whether the region in which the object motion is detected moves into the second mask image, and as the result of monitoring, if the object moves into the second mask image (Yes in S 34 ), the microcomputer  39  operatively controls the mask generator  40  to change one or more of the colors of the first mask image and second mask image (S 35 ). 
         [0040]    For instance, as shown in  FIG. 7 , with the colors of both of the first and second mask images changed to green, if the object motion moves into the second mask image, the color of the second mask image only is changed from green to red, thereby allowing the user to easily recognize that the object has moved into the second mask image. 
         [0041]    In addition, if the microcomputer  39  clears the multi-mask color control mode according to the user&#39; request (Yes in S 36 ), the colors of the first mask image and second mask image are changed to a previously set basic color (e.g., yellow) (S 37 ). 
         [0042]    Next,  FIG. 8  is a block diagram illustrating a monitoring camera according to an embodiment of the present invention. As shown, the monitoring camera includes similar components to that as shown in  FIG.3  and also includes an alarm module  44  and a wireless module  45 . That is, the monitoring camera shown in  FIG. 4  includes the zoom lens  30 , focus lens  31 , iris  32 , CCD  33 , amplifier  34 , signal processor  35 , mixer  36 , interface  37 , motor driver  38 , microcomputer  39 , mask generator  40 , memory  41 , keypad  42 , and detector  43  shown in  FIG. 3 , and also includes the alarm module  44  and wireless communication module  45 . 
         [0043]    In this embodiment of the present invention, the detector  43  detects an object motion from a camera image signal-processed by the signal processor  35 , and the microcomputer  39  monitors the movement position and movement direction of the detected object motion to thereby analyze the movement path of the object motion. 
         [0044]    As the result of analysis, if the object motion comes near or within a predetermined distance from the mask image while moving toward the mask image synthesized on a specific region of the camera image, the microcomputer  39  operatively controls the alarm module  44  to output a warning sound, or operatively controls the wireless communication module  45  to generate a warning message. The warning message can also be output to an external communication device connected through a wireless communication network. 
         [0045]    In more detail,  FIG. 9  is a flowchart illustrating a method for controlling the color of a mask of a monitoring camera according to a third embodiment of the present invention.  FIG. 8  will also be referred to in this description. 
         [0046]    As shown in  FIG. 9 , the microcomputer  39  sets, for example, a multi-mask color control mode according to a user&#39;s request or the like (S 50 ). For example, the microcomputer  39  operatively controls the mask generator  40  to synthesize a first mask image of a large size and a second mask image of a small size on a camera image as illustrated in  FIG. 10 . 
         [0047]    The detector  43  then receives a camera image signal output through the signal processor  35  and detects a motion of an object which has moved. For example, a current video frame (n) in which an image signal is processed in real time and a video frame (n- 1 ) in which an image signal has been previously processed are compared with each other to output a region in which an object motion is detected to the microcomputer  39 . 
         [0048]    In addition, the microcomputer  39  monitors the movement position and movement direction of the object motion to thereby analyze the movement path of the object motion (S 51 ). For example, as shown in  FIG. 10 , if the object motion comes close or within a predetermined distance from the first mask image while moving toward the first mask image, the microcomputer  39  predicts that the objection motion will move into the first mask image (Yes in S 52 ). 
         [0049]    Once the prediction is made, or the object motion moves into the first mask image, the microcomputer  39  operatively controls the alarm module  44  and the wireless communication module  45  to output a warning sound or warning message (S 53 ). For example, the microcomputer  39  operatively controls the alarm module  44  to output a warning sound so that people positioned around the monitoring camera can hear the warning sound, or operatively controls the wireless communication module  45  to generate a warning message and then output the message to an external communication device connected to a wireless communication network or the like so that a specific user can check the warning message through the external communication device. 
         [0050]    Further, the alarm module  44  can output a first warning sound or warning message when the object moves into an area defined by the first mask image and output a second warning sound or warning message that is different than the first warning sound or warning message such that the user can easily determine which area the object has moved into. The second warning sound or signal can also be more severe if the area defined by the second image area is designated by a user as being a more secure area than the area defined by the first image mask. 
         [0051]    Then, the microcomputer  39  operatively controls the mask generator  40  to change the colors of the first and second mask images to colors different from the previous colors (S 54 ). Moreover, the microcomputer  39  monitors whether the region in which the object motion is detected moves into the second mask image, and as the result of monitoring, if the object moves into the second mask image (Yes in S 55 ), the microcomputer  39  operatively controls the mask generator  40  to change one or more of the colors of the first mask image and second mask image (S 56 ). 
         [0052]    For instance, as shown in  FIG. 10 , with the colors of both of the first and second mask images changed to green, if the object moves into the second mask image, the color of the second mask image only is changed from green to red, thereby allowing the user to easily recognize that the object motion has moved into the second mask image. 
         [0053]    Also, if the microcomputer  39  clears the multi-mask color control mode according to the user&#39; request (Yes in S 57 ), the colors of the first mask image and second mask image are changed to a previously set basic color (e.g., yellow) (S 58 ). 
         [0054]    Further, the memory  41  may includes mask color table information that includes a relationship between mask colors and corresponding brightness values of camera images. For example, the mask colors and the corresponding brightness values of the camera images can be linked to one another in a one-to-one correspondence. 
         [0055]    As the present invention may be embodied in several forms without departing from the spirit or essential characteristics thereof, it should also be understood that the above-described embodiments are not limited by any of the details of the foregoing description, unless otherwise specified, but rather should be construed broadly within its spirit and scope as defined in the appended claims, and therefore all changes and modifications that fall within the metes and bounds of the claims, or equivalence of such metes and bounds are therefore intended to be embraced by the appended claims.