3rd stack GENTL (no VIN) : how to get timestamp

Programming Questions
, ,
4

Hi @Mikael,
there are multiple reasons why this is not working.

Using the EndOfLineMetadata of the Linea differs from handling Metadata/Chunk Data from different camera models.
In case of the Linea EndOfLineMetadata means that all information is added to the camera image using the last pixels for each line. The number of used pixels is depending on the number and type of activated metadata.
Here are example images from the Linea grabbed using the GenICam Browser:
Without Metadata:

grafik
grafik1103×75 468 Bytes

With Metadata Active (ExposureTime and Timestamp):

grafik
grafik1098×69 482 Bytes

The number of pixels per line stays equal to 2048 for the Linea 2K, so you will loose information from the pixels used for Metadata.

Now extracting these data from code in CVB could look like this:

using Stemmer.Cvb;
using Stemmer.Cvb.Driver;
using Stemmer.Cvb.GenApi;

namespace CVB_LineaMetadata
{
  internal class Program
  {
    static void Main(string[] args)
    {
      DiscoveryInformationList discoveryList = DeviceFactory.Discover(DiscoverFlags.IgnoreVins);
      if (discoveryList[0].AccessToken.Contains("Linea"))
      {
        //discoveryList[0].SetParameter("AttachChunk", "1");
        //Open Linea using GenTL
        using (Device device = DeviceFactory.Open(discoveryList[0]))
        {
          Stream stream = device.Stream;
          NodeMap nodemap = device.NodeMaps[NodeMapNames.Device];

          //Activating Metadata
          EnumerationNode metadatamode = nodemap["Cust::endOfLineMetadataMode"] as EnumerationNode;
          metadatamode.Value = "Active";
          EnumerationNode metadataContentSelector = nodemap["Cust::endOfLineMetadataContentSelector"] as EnumerationNode;
          EnumerationNode metadataContentActivationMode = nodemap["endOfLineMetadataContentActivationMode"] as EnumerationNode;
          metadataContentSelector.Value = "ExposureTime";
          metadataContentActivationMode.Value = "True";
          metadataContentSelector.Value = "Timestamp";
          metadataContentActivationMode.Value = "True";

          //Get Metadata Size
          long metadataPixelCount = (nodemap["Cust::endOfLineMetadataPixelCount"] as IntegerNode).Value;
          //Get Line Width
          long linewidth = (nodemap["Std::Width"] as IntegerNode).Value;
          long imageheight = (nodemap["Std::Height"] as IntegerNode).Value;
          byte[,] metadata = new byte[imageheight, metadataPixelCount];
          int offsetMetadata = (int)(linewidth - 1 - metadataPixelCount);
          //Start Stream
          stream.Start();
          for (int i = 0; i < 10; i++)
          {
            using(Image image = stream.Wait())
            {
              LinearAccessData<byte> imageData = image.Planes[0].GetLinearAccess<byte>();
              for(int y = 0; y < imageheight; y++)
              {
                for(int x = 0; x < metadataPixelCount; x++)
                {
                  metadata[y,x] = imageData[(x+ offsetMetadata), y];
                }
              }
              //Decode Metadata...
            }
          }
          stream.Abort();
        }
      }
    }
  }
}

Note that Chunk Data do not need to be activated on the driver side as theese are not Chunk Data in this context and just data that are written to the transmitted image.

To receive the FrameTriggerTimestamp you would need to use a completely different approach.
You will need to use Event handling to receive Cust::EventValidFrameTriggerTimestamp for each valid frame trigger. How to use event data, please have a look here.