Get Hardware Metadata from GenICam Device

The example shows how to acquire 10 images with hardware timestamps, CRC, and exposure time from a GenICam™ compliant camera using the gentl adaptor. The terminology for hardware metadata used by the GenICam standard is "chunk data."

Create a videoinput object, then configure it to acquire 10 frames and retrieve the videosource source object.

vid = videoinput("gentl", 1);
vid.FramesPerTrigger = 10;
src = getselectedsource(vid);

Use the chunkDataInfo function to view available chunk data that can be enabled for configuration.

chunkInfo = chunkDataInfo(src)

chunkInfo=15×2 table
            Chunk Data            Enabled
    __________________________    _______

    "ExposureTime"                "False"
    "Image"                       "True" 
    "CRC"                         "True" 
    "FrameID"                     "False"
    "OffsetX"                     "False"
    "OffsetY"                     "False"
    "Width"                       "False"
    "Height"                      "False"
    "Gain"                        "False"
    "BlackLevel"                  "False"
    "PixelFormat"                 "False"
    "SequencerSetActive"          "False"
    "Timestamp"                   "False"
    "SerialData"                  "False"
    "ExposureEndLineStatusAll"    "False"

Note that the Image and CRC Chunk Data are always enabled by default by the manufacturer of this particular camera.

Configure the camera to acquire timestamps and exposure times during acquisition.

% Activate chunk mode in the camera
src.ChunkModeActive = "True";
% Select the timestamp
src.ChunkSelector = "Timestamp";
% Enable timestamps
src.ChunkEnable = "True";
% Select exposure time
src.ChunkSelector = "ExposureTime";
% Enable exposure time
src.ChunkEnable = "True";

Use chunkDataInfo to verify that chunk data is configured correctly in the camera.

chunkInfo = chunkDataInfo(src)

chunkInfo=15×2 table
            Chunk Data            Enabled
    __________________________    _______

    "ExposureTime"                "True" 
    "Image"                       "True" 
    "CRC"                         "True" 
    "FrameID"                     "False"
    "OffsetX"                     "False"
    "OffsetY"                     "False"
    "Width"                       "False"
    "Height"                      "False"
    "Gain"                        "False"
    "BlackLevel"                  "False"
    "PixelFormat"                 "False"
    "SequencerSetActive"          "False"
    "Timestamp"                   "True" 
    "SerialData"                  "False"
    "ExposureEndLineStatusAll"    "False"

Start the acquisition and read the acquired data into the MATLAB workspace.

start(vid)
[image, time, metadata] = getdata(vid);

Access the metadata of the first frame.

mData = metadata(1)

mData = struct with fields:
          AbsTime: [2024 1 3 14 59 25.0336]
      FrameNumber: 1
    RelativeFrame: 1
     TriggerIndex: 1
        ChunkData: [1×1 struct]

Check the chunk data values for the first frame.

chunkMetaData = mData.ChunkData

chunkMetaData = struct with fields:
             CRC: 2948315233
    ExposureTime: 14963
       Timestamp: 1292485432754104

Display all chunk data for each frame in a table.

frames = [];
timeStamps = [];
exposureTime = [];
for i = 1:10
    img = image(:,:,:,i);
    frames = [frames; {img}];
    timeStamps = [timeStamps; metadata(i).ChunkData.Timestamp];
    exposureTime = [exposureTime; metadata(i).ChunkData.ExposureTime];
end
resultTable = table(timeStamps,exposureTime,frames)

resultTable=10×3 table
       timeStamps       exposureTime         frames      
    ________________    ____________    _________________

    1292485432754104       14963        {3000×4096 uint8}
    1292485532661568       14963        {3000×4096 uint8}
    1292485632569328       14963        {3000×4096 uint8}
    1292485732476568       14963        {3000×4096 uint8}
    1292485832384408       14963        {3000×4096 uint8}
    1292485932291568       14963        {3000×4096 uint8}
    1292486032199944       14963        {3000×4096 uint8}
    1292486132107456       14963        {3000×4096 uint8}
    1292486232014592       14963        {3000×4096 uint8}
    1292486331922328       14963        {3000×4096 uint8}