Record a video

You have the option to record with stimuli (manual or LED lights) if you own the Stimulus Controls module (see Using stimulus controls)

Procedure

  1. Click the video icon . WormLab displays the Video Capture dialog box along with the current status (e.g., Live view).
  2. The Capture tab is selected.
  3. Click the Folder button to select a folder to save your video files.
  4. Type a file prefix in the edit box. WormLab adds this to the beginning of the file name of each video file you capture.

    Do not use slashes ( / or \ ) in the prefix.

  5. Optional
    • Duration (hours:min:sec): Set the duration of your recording.
    • Time-lapse: Set the recording interval in seconds (between 0.25 sec and 3,600 sec).
    • Change Buffer value: Only consider increasing the value if your acquisition rate and resolution are high. The minimum value is 16 and the maximum value is 1024 frames.
  6. Check Open video after recording to load the recorded view in WormLab immediately after ending the recording.
  7. Press Record to start recording. Press Stop to stop recording.

Taking a snapshot while recording

Click Snapshot.

  • The snapshot is saved with the same file name prefix, but with a different extension (.PNG or .TIFF) and numbering system.
  • The snapshot is displayed temporarily under the Capture tab; it doesn't open in the Main window.

Video Capture settings

Display clipping

Click the Display clipping button to correct illumination. White pixels are displayed in red.

  • Adjust the aperture on your camera and/or lower the exposure in the Settings tab to correct imbalances.

Capture tab

Buffer: Only consider increasing the value if your acquisition rate and resolution are high. Range: 16-1024 frames.

Duration (hours:min:sec): Set the duration of your recording.

Timelapse: The Time-lapse function allows you to generate a video sequence with a lower temporal resolution than what the camera can acquire directly.

Ranges from 0.25 sec to 3,600 sec.

For example, if the camera’s lowest acquisition frame rate is 1 fps and you record a video for 30 seconds, the result is a video consisting of 30 frames. Let's say that you want to keep the duration (i.e., 30s) but you want to record a frame every 5 seconds (instead of every second). You will use the following settings:

  • Duration: 30 (seconds)
  • Time-lapse: 5 (seconds)

This will record a video with a total of 6 frames over the 30-second period.

Videos acquired with low temporal resolution have limited use; tracking results would not be valid, however , this functionality may be useful to validate whether a worm is still alive over a long period of time.

Show stimulus controls: Opens a separate window for LED light and manual stimulus management.

Snapshot: Click to take a snapshot while video is recording.

  • The snapshot is saved with the same file name prefix, but with a different extension (.PNG or .TIFF) and numbering system.
  • The snapshot is displayed temporarily under the Capture tab; it doesn't open in the Main window.

Settings tab

Access to camera settings is disabled during acquisition.

Color filter: Select to inform WormLab that the camera uses a color filter. Common with color cameras that use a color mask over a monochrome sensor to create a color image.

  • The values in the Color Filter drop-down list box specify the Bayer four-cell grid mask. There are always two greens in the four-cell grid color pattern. The quad grid is used to interpolate the values from the monochrome sensor to an RGB color value.
  • Contact Technical Services for assistance with color filters.

Exposure: Duration of the exposure in seconds.

Frame rate: Number of images captured per second. Frame rate is sometimes abbreviated as fps, or frames per second.

  • A lower frame rate lets you set a longer exposure.
  • For crawling worms, we recommend setting your frame rate between 5 and 14 fps.
  • For swimming worms, we recommended setting your frame rate between 14 and 30 fps

Gain: Use to create a brighter image without increasing the light source intensity.

An increase in gain results in an increase in noise.

  • We recommend that you first adjust exposure to increase the brightness. WormLab expresses gain as dB of intensity.
  • Increasing the gain intensity increases the electrical amplification of the signal.

Gamma: Gamma is a non-linear adjustment to the pixel intensity of an image. It is normally used to brighten the mid-tones.

  • A higher setting may bring out some shadow detail, which can be useful in low-light situations.
  • A value of 1 means that there is no adjustment.

Output: Select an output type. We recommend Monochrome.

Rotate 180: Use if the dish is upside-down.

Video mode: Select the camera's built-in video sizes and input modes from the drop-down list. Use FORMAT-7 to customize up to the maximum frame size supported by your camera.