/// <summary>Flushes the input buffer and tries to receive the next frame</summary>
bool CaptureFrame(out Image frame)
{
frame = new Image();
if (!IsConnected)
{
throw new ApplicationException("Cannot capture frames when no device is connected.");
}
const int FrameTimeout = 150; // ms
// Flush input queue to remove any desync with device stream.
GenICam.GigEVision_FlushInputQueue(DeviceHandle.Value);
// Await and receive first frame. If this frame gets corrupted or lost we need to explicitly react, otherwise we could
// crash because of single frame error or desync with device stream.
//mr?? GigEVision_TryReceiveImage() 是异步方法吗
//public static bool GigEVision_TryReceiveImage
//(
// int inDeviceHandle,
// int inTimeout,
// AvlNet.Image outImage,
// out ulong outFrameId,
// out ulong outTimestamp
//)
if (!GenICam.GigEVision_TryReceiveImage(DeviceHandle.Value, FrameTimeout, frame))
{
return(false);
}
return(true);
}
/// <summary>
/// Captures two sequent frames from the camera with different exposure parameter values.
/// Each frame is captured after explicit software trigger is sent to the device.
/// </summary>
private static bool CaptureFramesPair(int handle, double exposure1, double exposure2, Image outFrame1, Image outFrame2)
{
const int FrameTimeout = 150; // ms
// Flush input queue to remove any desync with device stream.
GenICam.GigEVision_FlushInputQueue(handle);
// Calculate timeouts for frames depending on required exposure time.
int timeoutFrame1 = FrameTimeout + (int)(exposure1 / 1000);
int timeoutFrame2 = FrameTimeout + (int)(exposure2 / 1000);
// Set first exposure time and capture the frame.
GenICam.GenApi_SetFloatParam(handle, "ExposureTimeAbs", exposure1);
GenICam.GenApi_ExecuteCommand(handle, "TriggerSoftware");
// Await and receive first frame. If this frame gets corrupted or lost we need to explicitly react, otherwise we could
// crash because of single frame error or desync with device stream.
if (!GenICam.GigEVision_TryReceiveImage(handle, timeoutFrame1, outFrame1))
{
return(false);
}
// Set second exposure time, capture and receive frame.
GenICam.GenApi_SetFloatParam(handle, "ExposureTimeAbs", exposure2);
GenICam.GenApi_ExecuteCommand(handle, "TriggerSoftware");
if (!GenICam.GigEVision_TryReceiveImage(handle, timeoutFrame2, outFrame2))
{
return(false);
}
return(true);
}