Supported hardware devices

Any compatible video device through OpenIGTLink interface. There are commercial systems that provide tracking video and image data through OpenIGTLink, such as BrainLab, Siemens MRI scanners

Device configuration settings

Type = "OpenIGTLinkVideo"
ServerAddress Host name or IP address of the OpenIGTLink server that sends the data to this device.
ServerPort Port of the OpenIGTLink server that sends the data to this device.
ImageMessageEmbeddedTransformName If IMAGE message is received and this attribute is defined then the transform embedded in the message will be recorded as a transform, with the specified name (e.g., "ImageToReference"). If the attribute is not defined then the embedded transform is ignored. If the message type is not IMAGE then the attribute is ignored.

Default = " "
MessageType The device will request this message type from the remote server. If the MessageType is not specified then the default message type will be used (specified in the remote server)

Default = " "
- IMAGE Request sending only image data in IMAGE OpenIGTLink messages.
- TRACKEDFRAME Request sending image+tracking data in TRACKEDFRAME OpenIGTLink messages.
IgtlMessageCrcCheckEnabled Enable CRC check on the received OpenIGTLink messages ( TRUE or FALSE).

Default = "FALSE"
UseReceivedTimestamps Use the timestamps that are stored in the OpenIGTLink messages.

Default = "TRUE"
- TRUE Timestamp in the OpenIGTLink message header is used as acquisition time for the item. If the remote server is on a different computer then the clocks of the remote server computer and the computer that runs PlusServer must be accurately synchronized (e.g., using NTP).
- FALSE Time of receiving the message is used as timestamp. Variable network delays may cause jitter in the timestamps.
ReconnectOnReceiveTimeout If this option is enabled and the server becomes unresponsive then the device tries to reconnect repeatedly ( TRUE or FALSE). It is usually desirable, because it makes the connection more robust, however in cases where server reconnection requires user approval it may be more convenient to turn this feature off.

Default = "TRUE"
ReceiveTimeoutSec Time to allow for the device to receive a message, in seconds.

Default = "0.5"
SendTimeoutSec Time to allow for the device to send a message, in seconds.

Default = "0.5"
AcquisitionRate The device checks for new available messages on the remove server at this rate.

Default = "30"
LocalTimeOffsetSec

Default = "0"
DataSources Exactly one DataSource child element is required.
- DataSource
  - PortUsImageOrientation
  - ImageType
    
    Default = "BRIGHTNESS"
  - BufferSize
    
    Default = "150"
  - AveragedItemsForFiltering
    
    Default = "20"
  - ClipRectangleOrigin
    
    Default = "0 0 0"
  - ClipRectangleSize
    
    Default = "0 0 0"

Example configuration file PlusDeviceSet_OpenIGTLinkVideoSource.xml

<PlusConfiguration version="2.1">
  <DataCollection StartupDelaySec="1.0">
    <DeviceSet 
      Name="TEST Data collection uses OpenIGTLink video source on localhost." 
      Description="Test configuration file for vtkDataCollectorFileTest to use a tracked frame list. The SequenceMetafile names should be defined either from command line argument or from configuration file!" />      
    <Device
        Id="OpenIGTLinkVideoSenderDevice"
        Type="OpenIGTLinkVideo"        
        MessageType="TrackedFrame"
        ServerAddress="127.0.0.1"
        ServerPort="18944"
        IgtlMessageCrcCheckEnabled="false" >
        <DataSources>
          <DataSource Type="Video" Id="Video" PortUsImageOrientation="MF"  />
        </DataSources>
        <OutputChannels>
          <OutputChannel Id="TrackedVideoSenderStream" VideoDataSourceId="Video" />
        </OutputChannels>
      </Device>  
  </DataCollection>
</PlusConfiguration>

This device can be used for transferring tracked video data to another computer for processing, recording, and broadcasting. This is useful in the following cases:

the computer where the data is acquired is not fast enough (for example, if frames are skipped during volume reconstruction: "Volume reconstruction cannot keep up with the acquisition. Skip ... seconds of the data stream to catch up.")
32-bit devices are used or a 32-bit computer is used for data acquisition, but high-resolution volume reconstruction requires 64-bit memory space

Example configuration file for data acquisition and sending (it acquires data from a file and forwards it through OpenIGTLink TRACKEDFRAME message to the processing server):

<PlusConfiguration version="2.1">
  <DataCollection StartupDelaySec="1.0" >
    <DeviceSet
      Name="PlusServer: TRACKEDFRAME acquisition server. fCal phantom scan with Ultrasonix US (L14-5 probe) + Ascension3DG tracker (Probe, Reference, Stylus)"
      Description="Free-hand probe motion, imaging 3 NWires, after spatial calibration. OpenIGTLink broadcasting of TRACKEDFRAME message through PlusServer." />
    <Device
      Id="TrackedVideoDevice"
      Type="SavedDataSource"
      SequenceFile="fCal_Test_Calibration_3NWires.igs.mha"
      UseData="IMAGE_AND_TRANSFORM"
      UseOriginalTimestamps="TRUE"
      RepeatEnabled="TRUE" >
      <DataSources>
        <DataSource Type="Video" Id="Video" />
      </DataSources>
      <OutputChannels>
        <OutputChannel Id="TrackedVideoStream" VideoDataSourceId="Video" />
      </OutputChannels>
    </Device>
  </DataCollection>
  <PlusOpenIGTLinkServer
    MaxNumberOfIgtlMessagesToSend="1"
    MaxTimeSpentWithProcessingMs="50"
    ListeningPort="18000"
    SendValidTransformsOnly="true"
    OutputChannelId="TrackedVideoStream" >
    <DefaultClientInfo>
      <MessageTypes>
        <Message Type="TRACKEDFRAME" />
      </MessageTypes>
    </DefaultClientInfo>
  </PlusOpenIGTLinkServer>
</PlusConfiguration>

Example configuration file for data receiving and processing (it acquires data from the acquisition server and allows recording, volume reconstruction, and broadcasting of IMAGE and TRANSFORM messages):

<PlusConfiguration version="2.1">
  <DataCollection StartupDelaySec="1.0" >
    <DeviceSet 
      Name="PlusServer: TRACKEDFRAME processing server"
      Description="To be used with TRACKEDFRAME acquisition server. Receives tracked frames through OpenIGTLink and it can record sequences, reconstruct volumes, and sends IMAGE and TRANSFORM messages through OpenIGTLink." />
    <Device
      Id="TrackedVideoDevice"
      Type="OpenIGTLinkVideo"
      MessageType="TRACKEDFRAME"
      ServerAddress="127.0.0.1"
      ServerPort="18000"
      IgtlMessageCrcCheckEnabled="false"
      LocalTimeOffsetSec="0" >
      <DataSources>
        <DataSource Type="Video" Id="Video" PortUsImageOrientation="MF"  />
      </DataSources>
      <OutputChannels>
        <OutputChannel Id="TrackedVideoStream" VideoDataSourceId="Video" />
      </OutputChannels>
    </Device>
    <Device
      Id="CaptureDevice"
      Type="VirtualCapture"
      BaseFilename="RecordingTest.igs.mha"
      EnableCapturingOnStart="FALSE" >
      <InputChannels>
        <InputChannel Id="TrackedVideoStream" />
      </InputChannels>
    </Device>
    <Device
      Id="VolumeReconstructorDevice"
      Type="VirtualVolumeReconstructor"
      OutputVolDeviceName="RecVol_Reference">
      <InputChannels>
        <InputChannel Id="TrackedVideoStream" />
      </InputChannels>
      <VolumeReconstruction
        ImageCoordinateFrame="Image" ReferenceCoordinateFrame="Reference"
        Interpolation="LINEAR" Optimization="NONE" CompoundingMode="MEAN" FillHoles="OFF" NumberOfThreads="2"
        ClipRectangleOrigin="0 0" ClipRectangleSize="820 616"
        OutputOrigin="-15 -15 30" OutputExtent="0 300 0 300 0 300" OutputSpacing="0.15 0.15 0.15" />
    </Device>
  </DataCollection>
    
  <PlusOpenIGTLinkServer
    MaxNumberOfIgtlMessagesToSend="1"
    MaxTimeSpentWithProcessingMs="50"
    ListeningPort="18944"
    SendValidTransformsOnly="true"
    OutputChannelId="TrackedVideoStream" >
    <DefaultClientInfo>
      <MessageTypes>
        <Message Type="IMAGE" />
        <Message Type="TRANSFORM" />
      </MessageTypes>
      <TransformNames> 
        <Transform Name="ProbeToTracker" />
        <Transform Name="ReferenceToTracker" />
        <Transform Name="ProbeToReference" />
      </TransformNames>
      <ImageNames>
        <Image Name="Image" EmbeddedTransformToFrame="Reference" />
      </ImageNames>
    </DefaultClientInfo>
  </PlusOpenIGTLinkServer>
  
  <CoordinateDefinitions>
    <Transform From="Image" To="TransducerOriginPixel"
      Matrix="
        1 0 0 -410
        0 1 0 5
        0 0 1 0
        0 0 0 1"
      Date="2011.12.06 17:57:00" />
    <Transform From="Phantom" To="Reference"
      Matrix="
        0.00898765 -0.0136951 -0.999866 9.59137
        0.0246163 -0.9996 0.0139127 36.0012
        -0.999657 -0.024738 -0.00864693 87.8909
        0 0 0 1"
      Error="0.404711" Date="012712_152104" />
    <Transform From="StylusTip" To="Stylus"
      Matrix="
        1 0 0 203.772
        0 1 0 -12.283
        0 0 1 1.17469
        0 0 0 1"
      Error="0.582721" Date="012712_152030" />
    <Transform From="Image" To="Probe"
      Matrix="
        0     0.08    0     11
        -0.08 0       0     50
        0     0       0.08  0
        0     0       0     1"
      Error="0.582721" Date="012712_152030" />
  </CoordinateDefinitions> 
    
</PlusConfiguration>