Patent Publication Number: US-2018035056-A1

Title: Tracking a target with an imaging system

Description:
BACKGROUND 
     Photographic systems use an imaging cameraman or photographer to watch through a viewfinder and reposition an imaging device to track the movement of a subject. Generally, one person is used for each imaging device. 
    
    
     
       DESCRIPTION OF THE DRAWINGS 
       Certain exemplary examples are described in the following detailed description and in reference to the drawings, in which: 
         FIG. 1  is a schematic drawing of an example of an imaging system pointing an imaging device at a target that has an attached transmitter; 
         FIG. 2  is a close up view of the imaging system, according to an example; 
         FIG. 3  is a schematic view of an example of a determination of the direction to the transmitter; 
         FIG. 4  is a schematic view of an example technique that may be used to point the imaging system at a transmitter; 
         FIG. 5  is an example of using the intensity of an infrared, or other optical, signal at each of the detectors, and to point the imaging system at the transmitter 
         FIG. 6  is a block diagram of an example control system for an imaging system; and 
         FIG. 7  is a process flow diagram of an example of a method for using a transmitter on a target to control the directional targeting of an imaging system. 
     
    
    
     DETAILED DESCRIPTION 
     Examples described herein provide a system to keep an imaging system pointed at a target with an attached transmitter based on radio signals received from the target. The system can include an imaging system, a control system, a transmitter, receivers, and motion apparatus. The motion apparatus includes mechanisms for panning and tilting the imaging device. The control system may also provide distance information to the imaging device to assist in focusing the imaging device at a target having the transmitter attached. The field-of-view can also be controlled to have the target occupy a consistent amount of the image size, this may be accomplished by zooming the imaging device in or out 
       FIG. 1  is a schematic drawing of an example of an imaging system  100  pointing an imaging device  102  at a target  104  that has an attached transmitter  106 . As used herein, the imaging device  102  may include a digital still camera, a digital movie camera, a film still camera, or a film movie camera. The transmitter  106  may be a small radio or infrared unit that is associated with the target  104 . For example, the transmitter  106  may be carried by the target  104 , attached to clothing, or installed inside an object, such as a ball, a car, and the like. The type of transmitter  106 , e.g., infrared or radio signal, may depend on the desired use. For example, if the target  104  is expected to be at a longer distance  108  from the imaging system  100 , a radio signal device may be used as the transmitter  106 . If the imaging system  100  is at a shorter distance  108  to the target  104 , an infrared emitter may be used as the transmitter  106 . Further, a radio signal device may be selected as the transmitter  106  if it is going to be hidden from view, such as in a pocket or an object. 
     The imaging system  100  includes the imaging device  102 , as well as a number of other units to point the imaging device  102  at the target  104 . The additional units can include horizontal detectors  110 A and  110 B and a vertical detector  112 . Although the detectors  110 A,  110 B, and  112  are shown in particular angular relations to the imaging device  102 , e.g., horizontally and vertically, it can be noted this is merely a convenience for the panning and lifting motions. The detectors  110 A,  110 B, and  112  can be placed at any number of angles, so long as the imaging system  100  is calibrated to move the imaging device  102  and track the transmitter. 
     A motion system  113  can be used to move  114  the imaging device  102 . Under the direction of a control system  116  the imaging device  102  is moved to track the transmitter  106  and, thus, the target  104 . These units are discussed in further detail in subsequent figures. The imaging device  102  can be supported in any number of ways. For example, a tripod  118  can be used to hold the imaging device  102 . 
       FIG. 2  is a close up f the imaging system  100 , according to an example. Like numbered items are as described with respect to  FIG. 1 . Control lines  202  couple the control system  116  to the imaging device  102 , the detectors  110 A,  110 B, and  112 , a panning motor  204 , and a tilting motor  206 . 
     Panning  208  the imaging device  102  involves rotating the imaging device  102  around a vertical axis  210 , for example, in a horizontal plane that includes the imaging device  102  and the transmitter  106  on the target  104  being imaged. Tilting the imaging device  102  involves rotating the imaging device  102  around a horizontal axis  214  through the imaging device  102 , for example, in a vertical plane that includes the imaging device  102  and the transmitter  106  on the target  104  being imaged. Focusing the imaging device may be performed by using a distance determination made by the control system  116 . Alternative, an autofocusing system located in the camera may be used. 
       FIG. 3  is a schematic view of an example of a determination of the direction to the transmitter  106 . Like numbered items are as described with respect to  FIG. 1 . The transmitter  106  and the detectors  110 A,  110 B, and  112 , may work or multiple channels or frequencies or codes that can be matched. This may allow multiple imaging systems to shoot the same subject or different imaging systems in the same area to image different targets without interference. 
     The determination of the direction to the target can be made by any number of techniques. Generally, the determination involves comparing the signal received from the transmitter  106  at each of the detectors  110 A,  1108 , and  112 , and then adjusting the direction of the imaging system  100  based on the results. In some cases, the direction of the imaging system  100  is adjusted to provide a matched signal at each detector  110 A,  110 B, and  112 . This is discussed further with respect to  FIGS. 4 and 5 . 
       FIG. 4  is a schematic view of an example technique that may be used to point the imaging system  100  at a transmitter  106 . Like numbered items are as described with respect to  FIG. 1 . In this example, the transmitter  106  broadcasts a pulsed radio signal, and the plots indicate the signal intensity at each of the detectors  110 A,  110 B, and  112 , e.g., I 1 , I 2 , and I 3 , respectively. A leading edge of a pulse  404  may be used to determine phase differences between each of the signals. A phase locked loop may be used to generate an error signal that can be used to adjust the direction of the imaging system  100  until all three antenna are in phase  406 . The pulse sequence may be used to identify the unit, so that multiple units may be used in the same area. In some examples, the frequency of the transmission may be specific to particular units, so that multiple camera systems may be used in the same area. 
     Any number of mathematical techniques may be used to determine the distance le the target in this example. For example, the ratio of the movements used to get the antennas in phase to the value of the phase error signal may be used to determine the distance to the transmitter. Targets that are farther from the imaging system  100  may use smaller corrections for a certain value of the error signal in comparison to targets that are closer. Other techniques may use the intensity of the signal to determine the distance. 
       FIG. 5  is an example of using the intensity of an infrared, or other optical, signal at each of the detectors  110 A,  110 B, and  112  to point the imaging system  100  at the transmitter  106 . In this case, the intensity of the signals, I A , I B , and I C , at each of the three detectors  110 A,  110 B, and  112 , respectively, can be normalized to a single intensity value, I T , by moving the imaging system  100 . In this example, the distance to the target may be calculated based on intensity of the signals. 
     Although the optical system may use an analog servo system, a pulsed optical system may be used, similar to the radio signal above. In this example, the direction adjustment may be made by comparing the phase of the optical signals, as described with respect to the pulsed radio signals. As for the radio system, the pulse sequence may be used to identify specific units. 
       FIG. 6  is a block diagram of an example control system  116  for an imaging system  100 . Like numbered items are as described with respect to  FIG. 1 . This control system  116  controls the movement of the imaging device  102  based upon the signal from the detectors  110 A,  110 B, and  112 . In some examples, the control system  116  is a proprietary computing device, a general computing device, a laptop computer, a desktop computer, and the like. As used herein, a proprietary computing device is a unit specifically designed to provide the targeting functionality. The control system  116  includes at least one processor  602 . The processor can be a single, core processor, a multicore processor, a processor cluster, and the like. The processor  602  is coupled to other units through a bus  604 . The bus  604  can include PCIe interconnects, PCIx, or any number of other suitable technologies. 
     The processor  602  can be linked through the bus  604  to a system memory  606 . The system memory  606  can include random access memory (RAM), including volatile memory such as static random-access memory (SRAM) and dynamic random-access memory (DRAM), non-volatile memory such as resistive random-access memory (RRAM), and any other suitable memory types or combinations thereof. The control system  116  can include a tangible, non-transitory, machine-readable storage medium, such as a storage device  608  for the long-term storage of instructions and data, including the operating programs and data such as user files. The storage device  608  may include a hard dive, a solid state drive, and the like. 
     The processor  602  may be coupled through the bus  604  to an I/O interface  610 . The I/O interlace  610  may be coupled to any suitable type of I/O devices, including input devices, such as a touch screen  612 , a mouse, a keyboard, a display, and the like. The I/O devices may also include external storage devices, such as hard drives, flash drives, and the like. The touch screen  612  may be used for the entry of control parameters to the control system  116 . 
     An actuator interface  614  may be coupled through the bus  604  to the processor  602 . The actuator interface  614  may include drivers to provide signals to drive the position of a pan motor  616  and a tilt motor  618 . Feedback signals from the motors  616  and  618  may be provided to the actuator interface  614 , for example, from optical encoders, Hall effect sensors, and the like. The feedback signals may be used to move the imaging system  100  to point at a particular position, for example, in the direction of origin of a signal. 
     A detector interface  620  may receive and process signals from the detectors  110 A,  110 B, and  112 . The detector interface  620  may be, for example, a three channel radio signal interface for couple to antennas. In some examples, the detector interface  620  may be a circuit designed to interface with optical detectors such as phototransistors. 
     An imaging device interface  622  may provide the control system  116  with a command and data interface to an imaging device  102 . The imaging device interface  622  may be a general purpose interface, such as a USB interface, an Ethernet interface, an Infiniband interface, a Firewire interface and the like. In some examples, the imaging device interface  622  may be an interface designed to work with a particular type of imaging device  102 . The imaging device interface  622  may be selected depending on the amount of imaging data being transfer to the control system  116 . In examples in which the imaging device  102  is a high definition video camera, a high bandwidth interface, such as an Infiniband interface may be used. In examples in which the imaging device  102  is a digital still camera, a USB interface may be sufficient. Further, in examples in which the imaging device  102  is a film camera, the imaging device interface  622  may be a proprietary bus, for example, used for shutter and film advance control. 
     The control system  116  can also include a wireless local area network interface controller (WLAN)  624 , for connecting the control system  116  to a network  626 . In some examples, the network  626  may be a local control computer, an enterprise server network, a local area network (LAN), a wide-area network (WAN), or the Internet, for example. 
     The control system  116  can include logic  602  to perform various functions for the imaging system  100 . For example, the storage device  608  may include a number of code modules to direct the processor. The control system  116  may also include hard wired logic to perform functions in addition to or instead of the code modules in the storage device  608 . 
     A tracking module  628  can include code to point the imaging device  102  at a target. This may include, for example, keeping the imaging device  102  tracking the target during fast motion of the target. 
     A focusing module  630  can provide distance information to the imaging device  102  to be used for focusing. In some examples, the focusing may be performed by the imaging device  102  itself. In these examples, the focusing module may be used merely to instruct the imaging device  102  to focus on the target. 
     A field-of-view (FOV) module  632  may be used to set the relation of the target to the total image captured by the imaging device  102 . The FOV module  632  may allow a user to set the relative location of the subject in the frame, or example, in the center, lower left, right, and the like. Further, the FOV module may determine the size of the area to be imaged, for example, relative to the target. In a group of people with one person carrying the transmitter, the area can be large to encompass ail persons. Further, if a target carrying the transmitter is on the left lower portion of the action to be captured, the location can be customized accordingly. For example, the customization may also include a distance to cover in each direction from the target point. If a transmitter is fitted on a person&#39;s foot, the area to cover may be extended above the transmitter to capture the person. 
     An autoshoot module  634  may be used to control the timing of the image capture. This may include a sequence entered by a user, for example, using the touchscreen, and external program, or a message received from a system of the network  626 . The image capture may include a single image, a series of images, or a start and stop time for a video recording. 
     A transfer module  636  may be used to obtain image data from an imaging device  102 . This may be useful for providing additional storage to the imaging device  102 . Further, this function may be used to obtain image data from the imaging device  102  and sending the data to a system located on the network  626 . 
     It is to be understood that the block diagram of  FIG. 6  is not intended to indicate that the control system  116  is to include all of the components shown in  FIG. 6 . Rather, the control system  116  can include fewer or additional components not illustrated in  FIG. 6 . For example, the control system  116  may include a high speed network coupling, such as an optical fiber or Ethernet connection. Further, the control system  116  may omit the I/O interface and touchscreen. In this, example, an external system, such as a laptop, may provide commands through the network interface. 
       FIG. 7  is a process flow diagram of an example of a method  700  for using a transmitter on a target to control the directional targeting of an imaging system. The method  700  begins at block  702  with The activation of a transmitter associated with a target, for example, as discussed with respect to  FIG. 1 . At block  704 , a detector system is activated to determine a direction to the signal from the transmitter, for example, as described with respect to  FIG. 3 , The detector system can include multiple antennas to determine the direction from a radio signal, for example, as discussed with respect to  FIG. 4 , or optical detectors, for example, as discussed respect to  FIG. 5 . 
     At block  706 , a control system can lock onto a signal from the transmitter. For example, an imaging system may be to work with a specific transmitter signal and to ignore other transmitters that may be operating in proximity to the control system. 
     At block  708 , the control system may move the imaging device to point at the transmitter. As discussed with respect to  FIG. 6 , this may include setting a custom offset from the center of the image, or example, if the transmitter is located farther away from the action. At block  710 , the imaging device may be focused on the target either by passing distance information from the control system to the camera, or by triggering the focusing system built into the camera. 
     At block  712 , the control system may zoom the imaging device to the selected field of view. As discussed herein, this may include a larger or smaller area around a target. In an example, this may be changed during recording of an image, for example, by a director changing a control. 
     It is to be understood that the block diagram of  FIG. 7  is not intended to indicate that the method  700  is to include all of the actions shown in  FIG. 7 . Rather, the method  700  can include fewer or additional components not illustrated in  FIG. 7 . For example, the method  700  may include an auto-shooting function to trigger the capture of the image data at a particular point in time, or using a preset start and stop time. Further, the control system  116  may omit the focusing function of block  710 . In this example, the imaging device may focus itself on the target while capturing the imaging data after a manual trigger. 
     While the present techniques may be susceptible to various modifications and alternative forms, the exemplary examples discussed above have been shown only by way of example. It is to be understood that the technique is not intended to be limited to the particular examples disclosed herein. Indeed, the present techniques include all alternatives, modifications, and equivalents falling within the scope of the present techniques.