Patent Publication Number: US-2011050904-A1

Title: Method and apparatus for camera control and picture composition

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application is a national stage entry of PCT/AU2009/000569 filed May 6, 2009, under the International Convention 
    
    
     FIELD OF THE INVENTION 
     The present invention relates generally to the field of broadcasting and in one aspect relates to a system for broadcasting a sporting event wherein the position of an object&#39;s image, within a camera&#39;s field frame, is biasly influenced by at least one biasing means. 
     BACKGROUND OF THE INVENTION 
     The popularity of sporting events, increased broadcast capabilities and viewers&#39; preferences have resulted in an increase in television coverage of such contests. There are now dedicated channels on free-to-air, satellite and cable television that provide 24-hour sports coverage. 
     The capacity of technologically advanced cameras to capture footage of sporting participants and events means that the viewer often has the best “seat in the house” without even having to leave their own home. Technological advances mean that cameras can be mounted within motor cars during race events and within cricket stumps. 
     Despite these advances many cameras used to capture sporting events are mounted on pan tilt heads and are controlled by an inaccurate human operator. During high speed sports such as motor racing rapid direction changes and complex framing are required. Currently available manually-controlled cameras are deficient in that they rely upon the skill level and reflexes of an operator. 
     Various camera-tracking systems have been suggested in paper publications that are able to track a target, wherein the target has a radio frequency or GPS tag attached thereto. These systems are however relatively simple and do not take into consideration complex framing and cinematographic composition. Furthermore the footage obtained from such camera systems is often jerky or erratic, which detracts from the viewing experience. 
     It should be appreciated that any discussion of the prior art throughout the specification is included solely for the purpose of providing a context for the present invention and should in no way be considered as an admission that such prior art was widely known or formed part of the common general knowledge in the field as it existed before the priority date of the application. 
     SUMMARY OF THE INVENTION 
     In accordance with an aspect of the invention, but not necessarily the broadest or only aspect there is proposed an apparatus for capturing video footage of a moving object, including at least one camera configured to follow the movement of said object, wherein the position of an image of said object, within a camera&#39;s picture frame, is influenced or biased by at least one biasing means. 
     The term picture frame, or frame, is used throughout the specification and refers to the edges of the camera lens&#39; field of view, or edges of the image as seen in a television, camera viewfinder or projected image onto a screen. A camera operator or motorised controller can be said to keep a car in frame by panning with it as it speeds past. In addition, the term point refers to a geometric element having a position located by coordinates, but no magnitude. 
     In a further aspect of the invention there is proposed an apparatus for capturing video footage of a moving object, including a plurality of movable cameras controlled by a control means, the control means being in communication with a tag device attached to said object such that at least one of said plurality of cameras tracks the movement of said object, wherein the position of an image of said object, within a respective camera&#39;s picture frame, is biased or influenced by at least one biasing means. 
     In one form the biasing means is a point within the camera&#39;s picture frame, or a magnetic line traversing at least a portion of the camera&#39;s picture frame. The position of the image of said object within the picture frame may be biased towards said point or magnetic line. 
     In another form the biasing means is a target frame within the camera&#39;s picture frame. The position of the image of said object within the camera&#39;s picture frame may be biased away from the target frame, such that the image of the object is retained within the target frame, and biased towards the centre of said target frame. The target frame may be located at any position within the frame to primarily allow for compositional requirements, but also to compensate for advertisement or statistics tables that may be incorporated into the broadcast images. The target frame may form any 2D shape which includes all rectangular, circular and oval shapes. 
     The biasing means may be a combination of a point, magnetic line and target frame that influences the position of the image of said object within the camera&#39;s picture frame. There may be a hierarchical system used to determine which constant influences the position of the image. It should be appreciated that different biasing means could be sequentially used. 
     Alternatively a user could change the position of the biasing means depending upon the footage that is required. 
     The tag device may be an active or passive tag that is attached to the object and is recognisable by the control means. 
     In one form the tag may be an active RFID tag, which may contain a battery and can transmit a radio-frequency signal autonomously. The active RFID tag will generally contain an integrated circuit for storing and processing information, modulating and/or demodulating a radio-frequency (RF) signal. The active tag typically also contains a transmitter attached to an antenna for transmitting a RF signal and may contain a receiver. 
     In another form the tag is a passive tag, which require an external source to initiate signal transmission. The passive tag may include special coatings applied to the object, readable information contained on a device such as a silicon chip, memory chip or any other device that can be read without physical contact between the detection means and the passive tag. 
     In one form the passive tag may include a reflection prism, bar code, microwave detectable means, microchip or be marked with RF readable alphanumerics. 
     The apparatus may be configured to track a plurality of objects each preferably having a respective tag device attached thereto. 
     In another aspect of the invention there is proposed a method of tracking at least one object with a video capturing device to obtain video footage of the moving object, including the steps of: 
     controlling at least one camera using a control means to track the movement of object; 
     moving the camera such that the position of an image of said object within the camera&#39;s picture frame, is biased or influenced by at least one biasing means. 
     At least one biasing means may be a point within the camera&#39;s picture frame, or a magnetic line traversing at least portion of the camera&#39;s picture frame, or a target frame within the camera&#39;s picture frame, or a combination thereof. 
     In one form the method includes the further step of ordering a plurality of tagged objects so that the control means can be used to select and deselect preferred objects for which video footage will be obtained using the video capturing device. 
     A broadcast manager may be in control of said camera and the ordering of tagged objects by way of a control means, wherein said manager determines the type of video footage obtained. 
     In yet another aspect of the invention there is proposed an apparatus for capturing video footage of a vehicle crash event, including a camera configured to selectively follow the movement of a vehicle to which a tag device is attached, wherein the position of an image of said tagged vehicle within a picture frame is biased or influenced by at least one biasing means, and a control means configured to analyse the movement of a tagged vehicle to anticipate if said vehicle is going to be involved in a future crash event, the control means including a virtual map of the race course and a data source having information relating to expected vehicle race lines, vehicle turning radius at specified speeds and conditions, and recommended maximum cornering speeds, wherein if said vehicle deviates from the expected race line or has a race alignment and speed that indicates a collision, or has a cornering speed that exceeds the recommended maximum cornering speed, or onboard accelerometers indicate a bump or crash, then said camera is controlled to follow and frame the movement of said vehicle in a specified manner. 
     In one form the control device can calculate the expected trajectory of said vehicle to determine the expected position of said crash event at the point where the expected trajectory of the vehicle intersects a roadside barrier, information of which is contained within said virtual map. This crash point may be used by the apparatus&#39;s cameras and system in their automated framing methods. 
     In still another aspect of the invention there is proposed an algorithm for controlling the operation of the preceding apparatus and for the apparatus&#39;s applications. In one form the algorithm is contained within a software program. The software program may be implemented as one or more modules for undertaking the steps of the present invention. The modules can be packaged functional hardware units for use with other components or modules. Multiple processing units may be used to control the operation of the apparatus. 
     Some of the components of the apparatus may be connected by way of a communication means such as, but not limited to, a RF Link, a modem communication path, a computer network such as a local area network (LAN), Internet, or fixed cables. 
     In one form the broadcast control means includes a computer having memory in the form of random access memory (RAM) and read-only memory (ROM), a central processing unit or units, input/output (IO) interfaces and at least one data storage device. The computer includes application software for controlling the servo encoded pan tilt heads, servo encoded zoom and focus lenses, and for undertaking the task of processing input data. 
     The processor and the memory cooperate with each other and with other components of a computer to perform all of the functionality described herein. In another form the processor executes appropriate software to perform all of the functionality described herein. In an alternate form, some or all of the functionality described herein can be accomplished with dedicated electronics hardwired to perform the described functions. 
     Application software may be stored in a computer readable medium on a storage device such as a floppy disk, a hard drive, a magneto-optical disk drive, CD-ROM, magnetic tape, integrated circuit, a radio or infra-red transmission channel between the computer and another device, a computer readable card such as a PCMCIA card, a flash drive or any other of the number of non-volatile storage devices. The foregoing is merely exemplary of relevant computer readable mediums. Other computer readable mediums may be practiced without departing from the scope of the invention. 
     In another form the apparatus includes embedded software or firmware with corresponding hardware that is designed to perform one or more dedicated functions of the present invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate implementations of the invention and, together with the description and claims, serve to explain the advantages and principles of the invention. In the drawings, 
         FIG. 1  is a schematic view of an embodiment of the biasing means of the present invention used to position the image of the object within the picture frame; 
         FIG. 2  is a perspective view of the biasing means of  FIG. 1  with respect to the three-dimensional space defined by the camera&#39;s lens; 
         FIG. 3   a - d  are schematic views illustrating different biasing means of the present invention; 
         FIG. 4  is a schematic view of an embodiment of the apparatus of the present invention; 
         FIG. 5  is a schematic view of a picture frame illustrating the position of a number of tracked targets and a mean target icon used in the present invention; and 
         FIG. 6  is a schematic view illustrating the crash aware function of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE ILLUSTRATED AND EXEMPLIFIED EMBODIMENTS 
     There are numerous specific details set forth in the following description. However, from the disclosure, it will be apparent to those skilled in the art that modifications and/or substitutions may be made without departing from the scope and spirit of the invention. In some circumstances specific details may have been omitted so as not to obscure the invention. Similar reference characters indicate corresponding parts throughout the drawings. 
     Referring to the drawings for a more detailed description, an apparatus  10  for capturing video footage of a moving object  12  is illustrated, demonstrating by way of examples, arrangements in which the principles of the present invention may be employed. As illustrated in  FIG. 1  the apparatus  10  includes at least one camera  14  configured to follow the movement of object  12 , wherein the position of an image  16  of the object  12 , within a camera&#39;s picture frame  18 , is biased or influenced, by at least one biasing means  22 . 
     To fully comprehend the present invention it is important to firstly examine the way in which video footage is obtained by the camera  14 . As illustrated in  FIG. 2  the picture frame is a two-dimensional image of a three-dimensional space  24 . This three-dimensional space  24 , within which objects are in focus, is defined by the field of view  26  and depth of field  28  of the camera  14 . The depth of field  28  has a minimum plane  30  and maximum plane  32  which are defined by the objective distances along the optical axis where an object appears to be “in-focus”, outside of this range an object will appear out of focus. Midway between the minimum  30  and maximum  32  extremes is plane  34 , where the object will be at optimal focus. It should be appreciated that the minimum plane  30 , maximum plane  32  and plane  34  are all curved. This is called the field curvation and is an attribute of the camera&#39;s lens. 
     It is envisaged that the biasing means  22  of the present invention will be placed on plane  34 . The biasing means  22  can be a point, magnetic line or target frame that is configured to attract or repel the image within the camera&#39;s picture frame  18 . As indicated by the object&#39;s path of travel  20  on the camera&#39;s picture plane, where the biasing means  22  is a point configured to attract the image  16 , the object  12  may be able to move, within the three-dimensional space  24 , along axes x, y, z, or simply two axes. 
     As illustrated in  FIG. 3   a , a radio frequency tag  36  is attached to the object  12 . In this way the object&#39;s position within the camera&#39;s picture frame  18  is known and the camera can move accordingly to capture footage of the object  12 . The use of a biasing means reduces jerky movement of the camera that may lead to viewer discomfort. As further illustrated in  FIG. 3   a  the biasing means  22  may be a point  38  that can be positioned at any location on the picture frame  18 . Alternatively, as illustrated in  FIG. 3   b  the biasing means  22  is a magnetic line  40 , having a start point  42  and end point  44 . The apparatus  10  can be configured so that the camera follows the object for a selected period of time such that the image  16  drifts along the magnetic line  40  from the start point  42  to the end point  44  being biasly weighted towards magnetic line  40  but being capable of drifting away therefrom. 
     In a further embodiment, as illustrated in  FIG. 3   c , the biasing means  22  is a target frame  46  within which the image  16  of the object  12  is biasly retained within the frame. The target frame  46  ensures that the image does not move outside a predefined area  46  of the screen but is nevertheless allowed a degree of movement. Therefore as the image  16  approaches the target frame  46  the camera is moved so that the image&#39;s position is changed to ensure it does not exit the target frame  46 . This embodiment may be used so that results or statistics can be selectively placed in a blank area  48  on the broadcast image without interfering with the image  16  of the race participant. 
     In yet a further embodiment, as illustrated in  FIG. 3   d , the biasing means  22  comprises a marker point  38 , magnetic line  40  and target frame  46  that controls the path of travel  20  of the image  16  and the movement of the camera  14  depending upon the position of the image  16  on the camera&#39;s picture frame  18 . It should be appreciated that other shapes and configurations of the biasing means  22  could be used. 
     The skilled addressee would appreciate that the further the object&#39;s image  16  moves away from, or toward, the biasing means  22  the stronger the influence will be. As the reader will appreciate this will be dependent upon whether the biasing means  22  is set to attract or repel the image  16 . By increasing the magnetic weighting of the biasing means  22  the path of travel  20  of the object&#39;s image  16  within the picture frame  18  away from or towards the biasing means  22  can be changed. Hence the operator is able to restrain the movement of the target or targets within the picture frame or alternatively allow a relatively large amount of movement of the image  16  within the picture frame  18 . Movement of the image  16  within the picture frame  18  is based upon the image&#39;s  16  speed and direction of travel, and the magnetic weighting of the biasing means  22 . The strength properties of the magnetic weight of the biasing means  22  includes but are not limited to, directly and inversely proportional behaviour, linear relationship behaviour, and logarithmic proportional behaviour. The size of the magnetic area surrounding the biasing means  22  within the picture frame  18  can be adjusted by the operator. 
     The apparatus is useful for sporting events such as motor racing and ball sports where the targets are moving at high speeds and are difficult to frame without rapid movement of camera, which unfortunately often produces footage that is jerky and less than desirable. The present invention provides a system for obtaining close-up footage without erratic movement of the picture. 
     When an operator is selecting an object  12  and a biasing means  22  referred to here as the marker point  38  is active, then the target is restrained around the marker point  38 . The image  16  continues to stay on or close to the marker point  38  proportional to the calibrated magnetic strength of the marker point  38 . The reader will now appreciate that a marker point  38  with high magnetic strength holds the image  16  firmly on to it, while a marker point with a low magnetic strength permits the image  16  to drift away and back to the marker point depending on the speed and direction of the target. 
     The principle function of the magnetic line  40  as illustrated in  FIG. 3   b  is to bring the image  16  close to the magnetic line  40  via the shortest route, and keep it on the magnetic line, proportional to the specified magnetic strength. The magnetic line  40  may be a straight line as illustrated in  FIG. 3   b  or it may be curved or shaped into any profile. The magnetic line  40  traverses the picture frame  18  at any angle or curve and at any location within the picture frame  18 . An optional feature is that the operator can specify how the target travels along the magnetic line  40  by nominating speed of travel with an entry  42  and an exit point  44 . The magnetic weighting, which allows for drifting of the object&#39;s image  16  produces a smooth visual cinematographic sequence between points  42  and  44 . 
     The magnetic line  40  requires four specified calibrations, firstly a percentage calibration which governs the strength of the magnetic attraction, secondly the size of the magnetic area or field surrounding the line  40 , thirdly a percentage calibration governing the speed that the object  12  can travel along the magnetic line  40 , and fourthly the acceleration or deceleration at which the target visually bounces off the target frame  46  or picture frame  18 . 
     The second and third calibrations involving speed and acceleration, and other live commands and presets can be linked to the master default setting, which can be used by all cameras  14  in the system. 
     The target frame  46  as illustrated in  FIG. 3   c  enables a singular image  16  or multiple images to be confined within the frame  46 . As such the target frame also controls the camera lens&#39; zoom calibration to ensure that multiple selected images  16  remain within the target frame  46  at all times regardless of their grouped or dispersed location. As with all of the biasing means  22  the target frame  46  can be activated or deactivated at any stage during camera operation. When active the selected target or targets are restrained within the target frame  46 . The edge of the target frame  46  has a magnetic weighting such that the object&#39;s image  16  is repelled. 
     This means that the object&#39;s image  16  remains within the predetermined area of the picture frame  18  however is still able to move or drift because of its own speed and changes in directions. This means that the cinematographic sequence will be smooth even in the event that the target is moving randomly and rapidly. The target frame is able to be adjustable in size, shape and location, thus creating a variable negative space between the target frame and picture frame. Shapes of target frames  46  include squares, rectangles, ovals and circles. 
     It should be noted that the target frame  46  can be used with dynamic tagged objects such as a soccer ball and static tagged objects such as a soccer goal, so that the two objects will always be within the target frame  46 . It should also be noted that it can be used with two dynamic tagged objects such as a cricket player and the cricket ball. 
     The target frame&#39;s  46  four calibrations are; strength, size, speed and acceleration. The following is an elaboration of these: 
     Strength calibration—100% (the highest) pushes the object&#39;s image  16  furthest away from the edge of the frame  46 . 0% Strength calibration allows the target to float (according to its own direction) within the frame and touch the edge of the frame  46 . 
     Size calibration expands and contracts the size of the frame. Size calibration 100%—target frame  46  equals size of the picture frame  18 . Size calibration 600% equals target frame six times larger than picture frame  18 . Size calibration 50% equals target frame  46  half picture frame  18 . 
     The speed of the image  16  within the target frame must be specified. For instance, specifying the master default will use the calibrations of the master default pan speed. 
     Acceleration within the target frame must be specified. For instance, specifying the master default will adopt those pan tilt acceleration calibrations. 
     Maximum and minimum zoom speeds can be individually specified or can be defaulted from the master default zoom speeds. Specified maximum and minimum zoom speeds stop excessive blurring and provide a desired working range. 
     The target frame  46  works in conjunction with the zoom function, thus as the selected targets visually spread out and touch the target frame, the automatic zoom zooms out enabling all selected targets  12  to remain within the target frame  46 . As the selected targets converge, the zoom increases. If the target frame  46  is off then the picture frame  18  becomes the defining edge for the automatic zoom function. 
     The target&#39;s path or drift  20  through the target frame  46  has four options which must be specified. 
     1. Engage other ordering devices e.g. the magnetic line or marker point with the target frame. 
     2. The target may drift within the frame according to its own direction. 
     3. The angle of collision on the target frame equals a reflected angle of deflection. 
     4. The target is bounced off the target frame towards the centre after it contacts the frame. 
     In a further embodiment the tracking system can determine the trajectory of a ball being tagged and can identify a landing zone and the tagged players closest to that landing zone. As such a target frame  46  can be used to frame both tagged player and ball as both objects collide. Alternatively the operator may simply frame the player closest to the landing zone in a previously specified manner. 
     In a further embodiment, as illustrated in  FIG. 4 , the apparatus  10  comprises a radio frequency tracking system  50  that uses triangulation to locate selected objects  12  having respective RF tags  36  attached thereto. The selected objects  12  are within a preselected area such as a race course  52 . It should however be appreciated that other tracking systems can be used, such as radar type tracking, optical recognition or DGPS devices. The tags  36  may be either active or passive as is well known in the art. 
     The apparatus  10  further includes a central processing unit  54  (CPU) and receivers  56 . It is envisaged that the system  10  will include a plurality of receivers coupled to respective antennae which are located around the race course  52  or sporting field. Each receiver  56  is linked via fibre optic cabling or telemetry back to the tracking CPU  54 . 
     This tracking CPU  54  relays to the camera CPU  68  the exact location of each tagged object  12 . Cameras  14  can be zoomed in and focused on the desired tagged targets  12 . The camera CPU  68  relays the pan, tilt, zoom and focus requirements to the cameras  14  by way of fibre optic cabling or alternative by way of a transmitter (not shown). The images  58  captured by the plurality of cameras  14  are conveyed back to the CPU  68  and the operator or director  60  is able to select the cinematic picture  62  suitable for broadcasting  64 . 
     It is envisaged that each camera  14  will incorporate a servo encoded pan tilt head with tripod support as is well known in the art. However, the reader should appreciate that other camera operating system can be used including boom-mounted and dolly mounted cameras, and cameras suspended from cables in a flying fox configuration. Broadcast cameras and lenses are mounted on the servo encoded pan tilt heads, which align their pan tilt axes with dynamic accuracies of 0.03 degrees or better at the targets  12 . 
     The camera controls  66  facilitate use of the various aspects of the invention and typically have ergonomic controls, joy sticks, live and preset function keys, calibration dials and a variety of computer-based commands enabling detailed and progressive composition of the cinematic pictures. The camera controls  66  work in conjunction with the computer  68  and camera screen interface  62 . Where several cameras or computers are being used, they will all be linked to the central processing unit  54 . 
     The software commands can be utilised by individual cameras  14  and also by a Director who can manage all selected cameras  14  in a coordinated network. 
     The apparatuses&#39; software commands can be broken into four basic distinct groups and are as follows:
         1. Target lock-on—these commands enable the operator to capture desired tagged target or targets and track them using a camera or cameras. These commands include: engaging automatic mode; manual entry of target number; addition and subtraction; travelling keys; and priority targets.   2. Biasing Means  22 —the marker point  38 , magnetic line  40  and target frame  46  can be set individually for each camera  14 , or all cameras can utilise the master default biasing means  22 . Biasing means  22  enable aesthetic framing, proportion, target placement within picture frame, speed and acceleration.   3. Live commands—these commands enable selected target or targets to be viewed and visually sequenced in a prescribed manner. These commands include: dynamic zoom shift; dynamic pan shift; collision framing; destination framing; and repeat.   4. Director&#39;s override—these commands enable the director to override individual operator controls and presets, and facilitate the coordination of all servo encoded pan tilt heads and associated cameras in a variety of ways. These commands include: unification; director&#39;s presets; accident aware; priority targets; and graphics allowance.       

     The tag  36  attached to each object  12  may emit a different individual frequency. This means that each of the targets  12  can be identified with an assigned number that appears within a target&#39;s icon on the operator&#39;s screen  62 . The target icon that appears on the operator&#39;s screen  62  can be selected by typing the associated number using the function keys or by moving crosshairs over the object&#39;s image  16  using a mouse or joystick. Target lock-on enables the operator to select one or more targets and frame them within the predetermined frame or portion of the picture frame. It is envisaged that there will be several different ways of locking onto or selecting a target. Some of the methods are as follows:
         1. When changing from manual mode to automatic mode the system recognises any targets within the target frame (if active) and locks on automatically.   2. Manual entry, which requires the operator to key in the target&#39;s I.D. number via the controls. Similarly targets can be removed by entering for example “-X enter” using the function keys.   3. Priority targets are selected by the director on the master control which is then relayed to the individual operators. The operator may switch automatic priority targets to active, which will automatically lock-on to the priority target when within camera viewing area. When priority targets are within the specified camera viewing area, the target icon both on the screen and in the target order will flash red until it has been selected. The priority target icon when selected remains red.   4. Addition and subtraction keys on the controls are used to add or remove targets from the selected targets. There are two sets of addition and subtraction keys. The first set of keys controls the adding or removing from the front selected targets, e.g. from the leaders. The second set of keys controls the adding and removing from the rear of the selected targets, i.e. from the followers. This is particularly useful under race conditions.   5. Travelling keys can also be used in changing selected targets. If two targets have been selected i.e. 2nd &amp; 3rd place and the positive travelling key is pressed then the selected targets become 1st &amp; 2nd place. Similarly, pressing the negative travelling key when 2nd &amp; 3rd place are selected will result in 3rd &amp; 4th place being tracked.   6. If the automatic function is selected and no targets are being tracked, the function keys can be used to select the target closest to the centre of the picture frame, or the target nearest a preselected point or magnetic line within the picture frame.       

     As illustrated in  FIG. 5  the apparatus  10  can be used to track a number of objects. In the present example race vehicles  70 ,  72 ,  74 , to which respective tags  36  are attached, are tracked by apparatus  10 . The position of the respective images  76 ,  78 ,  80  within the camera&#39;s picture frame  18  are determined by the mean target location (MTL)  82  that is influenced by the biasing means  22 , in this example being a point  38 . When two or more objects have been selected and the target frame and the automatic zoom are active, then the zoom will automatically maximize the zoom calibration while still retaining all the selected targets within the camera&#39;s picture frame  18  or a specified target frame  46 . 
     When two or more objects  12  are selected then the MTL icon  82  will appear on the screen  62 . The MTL  82  becomes the defined target&#39;s location within the picture frame  18  when determining picture composition with the biasing means  22 . 
     Acceleration and deceleration zoom calibrations can be preset to ensure that the camera does not move too quickly which may lead to viewer discomfort. Automatic zoom is enabled when the system is in the automatic mode and a target or targets have been selected. The automatic zoom, when used in tracking a single target, enables the selected target to stay as a fixed proportion or fixed visual size of the target frame. Thus the target appears not to change in size as its focus changes and the automatic zoom adjusts. The operator can still change the automatic zoom setting via the camera control  66 , after which the latest setting and thus visual size becomes the default setting. 
     Automatic focus is enabled when the system is in automatic mode and a target or targets have been selected. Because the target is being tracked the subject distance between camera and target is a known value and the system is calibrated to ensure that the target is in focus at all times. It is therefore important for the operator to specify one of the following parameters for this command:
         1. Use the mean target location (MTL) as the focal length, or   2. Use the leading target for the focal length calculation, or   3. Use target closest to screen centre point (CP) for the focal length calculation, or   4. Use best fit, which uses both MTL and CP for calculation.       

     If the biasing means  22  are not active and an object  12  is selected, then the object&#39;s image  16  will remain in the same location within the picture frame  18  as it was when it was initially selected. The operator can shift this selected target or mean target location within the picture frame  18  via the live interaction mode through the joystick or any other mechanism. If the centre point of the picture is on the live interaction mode the operator can shift the target away from the centre point of the picture, but once joystick pressure is released then the target will move back to the centre point. Live interaction mode can be used within all commands with the exception of director&#39;s override commands. 
     Pan &amp; zoom acceleration are individually adjustable percentage calibrations, which govern the rate that an object image  16  travels across the picture frame  18  and the zoom speed. High percentages correspond to sharp and aggressive changes. Low percentages give gentle and slow changes. The master default pan and zoom acceleration and speed are specified in the system preset and govern all pan and zoom acceleration and speed settings within the commands, on the proviso that the commands are set to master. Each command can have its own specified pan and zoom acceleration &amp; speed calibrations. 
     The speed bar governs the speed (forward and reverse) at which the dynamic zoom, dynamic pan and live commands are performed. For example, if a dynamic pan command is engaged with a specified pan speed of 50% (moderate) and the speed bar is pushed fully forward, then the choreographed dynamic pan command will increase its pan speed to 100%. In effect the speed bar combines all specified pan and zoom acceleration &amp; speed calibrations and collectively and proportionally changes them depending on the movement of the speed bar. The master pan and zoom acceleration &amp; speed are utilised in a variety of live commands and presets. These include automatic zoom, dynamic pan, changing selected targets, and camera story lines. Master pan and zoom acceleration &amp; speed have percentage calibrated, which are governed by individual calibrated dials on the control interface. 
     Dynamic zoom is a live command that zooms in or out on specified selected targets. For each dynamic zoom the operator must specify the: 
     Pan start point and finish point locations. 
     Start and finish zoom calibration. 
     Zoom speed and acceleration. 
     Specifying the vehicle type, scenario number, creating a scenario and the zoom and pan calibrations for speed, acceleration, start and finish points is all performed through the CPU  68 . The software has many standard dynamic zooms in the library and facilitates additional dynamic zooms to be created, catalogued and loaded for future use. Numerous dynamic zoom and dynamic pans can be linked together into a single live command. All live commands (eg. a dynamic zoom) have a genesis scene, which is created from the command start point, zoom calibrations and ordering biasing means  22 . If the live command button on the camera control  66  is pressed and held down then the dynamic zoom scene will remain at the genesis scene calibrations. This action is called a genesis hold. When the button is released then the remainder of the command will be instigated. Each choreographed scenario is performed at specified speed and acceleration rates. These combined rates may be changed using the speed bar. The speed bar enables the choreographed scene to be sped up or even reversed. 
     A dynamic pan function pans across a selected target or targets from a specified pan start point to a specified pan finish point along a specified travel path with intermediate points, within specified pan speed, pan acceleration and zoom calibrations. The command itself is intrinsically the same as the dynamic zoom shift, except one is calibrated for zooming and the other panning. This is useful for the operator in organising the commands. The pan shift command requires a specified path of travel upon which the target tag or the MTL of numerous targets travels. The software facilitates dynamic pans to be created, catalogued and loaded for future use. Each dynamic pan scenario can be loaded onto a live button. As the reader would now appreciate a dynamic pan command enables panning from the front of the selected vehicle (i.e. F 1 ) to its rear at a specified pan and zoom calibration. 
     In a further embodiment of the invention, as illustrated in  FIG. 6 , the apparatus  10  incorporates a vehicle crash event function  84 . In such an embodiment  84  the camera  14  is configured to selectively follow the movement of a vehicle  12  to which a tag device  36  is attached and a control means  86  configured to analyse the movement of a tagged vehicle  12  to anticipate if said vehicle  12  is going to be involved in a future crash event  88 , the control means  86  including a virtual map of the race course  90  and a data source having information relating to expected vehicle race lines  92 , cornering ability and recommended maximum cornering speed, wherein if said vehicle  12  deviates  94  from the expected race line  92 , has no chance of making a corner, or has a cornering speed that exceeds the recommended maximum cornering speed said camera is controlled to follow and frame the movement of the vehicle  12  in a previously specified manner. 
     In use the tagged race car  12  moves along the race track  90  at known speed and direction. The central processing unit  86  is able to calculate the racing line  92  under the present race conditions such as weather. If the tagged vehicle  12  deviates  94  from this racing line  92  or if the vehicle  12  is approaching a corner at too great a speed the CPU  86  is able to calculate that the vehicle is about to lose control. Since the speed and direction of the vehicle is known the CPU  86  is able to calculate an approximate crash path  96 . The system can include information about the layout of the circuit such that the CPU  86  is able to control cameras  14  to capture footage of the impact  88 . Live interaction through the joystick is permitted. The camera will stay selected to the accident aware target until lock off by the operator. No automatic commands such as priority targets will override the accident aware command with the exception of another accident aware command. The operator may lock off the accident aware target with another command or delete at any time. Once a target has departed from the track for more than a specified period of time, it is classified as dead. A dead target is tracked but will not activate the accident aware command by being off the race track. A dead target may become alive if it passes onto the track. 
     The operating system specifies the maximum cornering speeds of vehicles and camber of track surfaces, the acceleration and deceleration rates and specification of time period between deviation from track and when target is classified as dead. This time period may be set as a default of five seconds. Individual cameras can have their preset zoom, centre point and target frame calibrations set as required for each camera location. 
     The operator can nominate priority targets such as race leaders. When the priority targets enter a camera&#39;s viewing area the camera automatically locks on to the priority target and overrides currently selected targets. Priority targets may be set by individual camera operators or by the director. 
     The various aspects of the invention relate to picture composition and control of a camera or cameras used to obtain footage of an event such as a sporting contest. There are several features covered by the invention including, but not limited to, a tracking system, picture composition, camera controls, and software commands. The reader should appreciate that each of these features can be used in combination or alternatively can be used in isolation from each other. 
     As the reader will now appreciate when biasing means  22 , such as a point  38 , are used to restrain the object&#39;s image  16  around the preselected position within the picture frame  18  the jerky movement of the camera  14  is reduced which results in footage that is smooth. The point  38  can be positioned anywhere within the picture frame  18  which means that the object&#39;s image  16  can be restrained to a position distinct from the actual centre point of the picture frame  18 . This is useful for compositional control and allowing for screen graphics. The marker point  38  has a magnetic weighting, which attracts the object  12 . Accordingly, the camera  14  is adjusted to thereby restrain the movement of the object&#39;s image  16  within the picture frame  18  such that the object&#39;s image  16  moves or drifts around the point  38  as illustrated by dotted line  20 . 
     The skilled addressee will now appreciate the many advantages of the present invention. The invention overcomes the issues relating to the reliance on human accuracy and agility to focus on and frame a subject. The system can be used to frame a target moving at high speed such as a race car or football without producing erratic footage. 
     Various features of the invention have been particularly shown and described in connection with the exemplified embodiments of the invention, however, it must be understood that these particular arrangements merely illustrate and that the invention is not limited thereto. Accordingly the invention can include various modifications, which fall within the spirit and scope of the invention. It should be further understood that for the purpose of the specification the word “comprise” or “comprising” means “including but not limited to”.