Mask cameras

Before you begin calibrating, make sure that your camera views are clear of any unwanted reflections, whether they originate from markers or reflective materials in your lab. In either case, try to physically remove or cover the source of any reflections that are shown in each camera view as they can be mistaken for markers by the cameras. You can check the source of these reflections by using Video Preview Mode (see Configure Vicon cameras). If removing the source of the reflections is not possible, you must mask your cameras to remove the pixels caused by the reflections so that they don't influence the 3D data.

If your camera view is not masked, you can see reflections represented by light pixels in the Cameras view. During masking, blue pixels are drawn in the Cameras view, enabling you to see how much of the view is masked.

To automatically mask reflections:

1. Ensure you have removed from the capture volume any unnecessary objects, such as calibration objects, likely to cause background interference. Note that, to start masking, at least one camera must be contributing data.
2. In the Workspace, select the Cameras view.

   

3. In the System panel, select all the cameras (SHIFT+click or drag or right-click and then click Select All Cameras).

   Tip: If you are already in the cameras view with a single camera selected, double-click within the camera view to display all cameras.

4. In the Camera Calibration panel, under Masking, click Mask All.

   The button displays Stop and at the top of the workspace, the menu bar changes color and Auto Mask Active is displayed.

   On the cameras, the status lights turn cyan while auto masking is in progress.

   Tracker starts tracking the data visible to each of the connected cameras. Any camera masks created are displayed as blue cells in the Cameras views for affected cameras. If no data is visible to a particular camera, Tracker does not create any masks for it.

5. Once all the light pixels in each camera have turned to blue, click Stop. The duration of this process depends on the number of cameras in your system.
6. In the Cameras view for each camera, ensure that any unwanted reflections are eliminated. (Each view must either be completely blank or contain some blue pixels.)

If the automatic camera masking that is described above does not eliminate all the unwanted reflections, you can manually remove any remaining reflections as follows.

To define camera masks manually:

1. In the System panel (Vicon Cameras list) or 3D View, select a single camera.

2. In the Camera Calibration panel, go to the Masking section and ensure the advanced options are displayed (if necessary, click Advanced Parameters at the top right).

3. To begin editing the selected camera mask, click Manual Mask Paint.

4. In the Cameras view:

   • Alt+drag to select a mask area

     

   • Press E to add the current selection to the mask

     

   • Press R to remove the current selection

     

5. To apply the changes, click Stop.

   To revert to the original mask, click Cancel.

You can now wave the calibration wand throughout the volume (see Perform a wand wave).