/// <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);
}
/// <summary>
/// <para>Setups and verifies capabilities of general camera device of unknown type for this demo. Usually
/// application should be created for specific device or device class, some of this setup and verification is
/// not obligatory.</para>
/// <para>Device parameter setup is based on GenICam SFNC standard.</para>
/// </summary>
static void SetupDevice(int handle)
{
Console.WriteLine("Setting up device...");
// Device parameter setup is based on GenICam SFNC standard.
// When selector is available, select "FrameStart" trigger in device. This parameter
// must be set first because it determines what further parameters point to.
if (GenICam.GenApi_GetParamExists(handle, "TriggerSelector"))
{
GenICam.GenApi_GetEnumParam(handle, "TriggerSelector", true, out defaultTriggerSelector);
GenICam.GenApi_SetEnumParam(handle, "TriggerSelector", "FrameStart", true);
}
// Setup device so that it waits for software command to trigger new frame.
GenICam.GenApi_GetEnumParam(handle, "TriggerSource", true, out defaultTriggerSource);
GenICam.GenApi_SetEnumParam(handle, "TriggerSource", "Software", true);
// Verify that command for software trigger exists.
if (!GenICam.GenApi_GetParamExists(handle, "TriggerSoftware"))
{
throw new MemberAccessException("Command \"TriggerSoftware\" is not defined by device description.");
}
// Enable trigger
if (GenICam.GenApi_GetParamExists(handle, "TriggerMode"))
{
GenICam.GenApi_GetEnumParam(handle, "TriggerMode", true, out defaultTriggerMode);
GenICam.GenApi_SetEnumParam(handle, "TriggerMode", "On", true);
}
// Set acquisition mode to continuous - device should continue to
// wait for triggers after each frame capture.
GenICam.GenApi_SetEnumParam(handle, "AcquisitionMode", "Continuous", true);
// If this device has automatic exposure, turn it off - we will be controlling
// this parameter manually.
if (GenICam.GenApi_GetParamExists(handle, "ExposureAuto"))
{
GenICam.GenApi_SetEnumParam(handle, "ExposureAuto", "Off", false);
}
// Set initial exposure value (this will also verify, if parameter is available).
GenICam.GenApi_SetFloatParam(handle, "ExposureTimeAbs", 15000, true);
}