Camera Video Types
An overview of the different video modes available on the OptiTrack cameras.
Last updated
Was this helpful?
v3.2
An overview of the different video modes available on the OptiTrack cameras.
Last updated
Was this helpful?
Captured frames are processed differently based on the video mode the camera is set to during recording. Only the configured video mode is recorded and saved in Take files.
Video types, or image-processing modes, available in OptiTrack Cameras:
OptiTrack cameras have different image-processing modes, referred to as video types in Motive. Each mode processes captured frames differently at both the camera hardware and software levels.
The precision of the capture and the required amount of CPU resources will vary depending on the configured video type.
The available modes vary some by camera model.
The video types are categorized as either tracking modes (object mode and precision mode) or reference modes (MJPEG and raw grayscale). Only cameras in tracking modes will contribute to the reconstruction of 3D data.
(Tracking Mode) Object mode performs on-camera detection of centroid location, size, and roundness of the markers, and then, respective 2D object metrics are sent to the host PC. In general, this mode is best recommended for obtaining the 3D data. Compared to other processing modes, the Object mode provides smallest CPU footprint and, as a result, lowest processing latency can be achieved while maintaining the high accuracy. However, be aware that the 2D reflections are truncated into object metrics in this mode. The Object mode is beneficial for Prime Series and Flex 13 cameras when lowest latency is necessary or when the CPU performance is taxed by Precision Grayscale mode (e.g. high camera counts using a less powerful CPU).
Supported Camera Models: Prime/PrimeX series, Flex 13, and S250e camera models.
(Tracking Mode) Precision Mode performs on-camera calculations of what pixels are over the threshold value plus a two pixel halo around the above-threshold pixels. These pixels are sent to the PC for additional processing and determination of the precise centroid location.
Precision mode provides quality centroid locations but is very computationally expensive and network bandwidth intensive. It is only recommended for low to moderate camera count systems for 3D tracking when the Object Mode is unavailable or when using the 0.3 MegaPixel USB cameras.
Supported Camera Models: Flex series, Tracking Bars, S250e, Slim13e, and Prime 13 series camera models.
(Reference Mode) The MJPEG -compressed grayscale mode captures grayscale frames, compressed on-camera for scalable reference video capabilities. Grayscale images are used only for reference purpose, and processed frames will not contribute to the reconstruction of 3D data. The MJPEG mode can run at full frame rate and be synchronized with tracking cameras.
Supported Camera Models: All camera models.
(Reference Mode) Processes full resolution, uncompressed, grayscale images. The grayscale mode is designed to be used only for reference purposes, and processed frames will not contribute to the reconstruction of 3D data. Because of the high bandwidth associated with sending raw grayscale frames, this mode is not fully synchronized with other tracking cameras and they will run at lower frame rate. Also, raw grayscale videos cannot be exported out from a recording. Use this video mode only for aiming and monitoring the camera views for diagnosing tracking problems.
Supported Camera Models: All camera models.
You can select a camera or cameras and use the associated hotkey to change the video mode.
Object: O
Grayscale: U
MJPEG: I
From Perspective View
In the perspective view, right-click on a camera from the viewport and set the camera to the desired video mode.
From Cameras View
In the cameras view, right-click on a camera view and change the video type for the selected camera.
Compared to object images that are taken by non-reference cameras in the system, MJPEG videos are larger in data size, and recording reference video consumes more network bandwidth. High amount data traffic can increase the system latency or cause reductions in the system frame rate. For this reason, we recommend setting no more than one or two cameras to Reference mode. Reference views can be observed from either the Camera Preview pane or by selecting Video and selecting the camera that is in MJPEG mode from the Viewport dropdown.
If Greyscale mode is selected during a recording instead of MJPEG, no reference video will be recorded and the data from that camera will display a black screen. Full greyscale is strictly used for aiming and focusing cameras.
To switch between image processing modes, simply right-click on the camera from the pane and select the desired video type.
You can check and/or change the video type of the selected camera from either the , the , or the in the . Hotkeys can also be used to change the video type.
From the , click the Mode icon for the selected camera to toggle between frequently used modes for each camera.
Open the and and select one or more cameras listed. Once the selection is made, respective camera properties will be shown on the properties pane. Current video type will be shown in the Video Mode section and you can change it using the drop-down menu.
Cameras can also be set to record reference videos during capture. When using MJPEG mode, these videos are synchronized with other captured frames, and they are used to observe what goes on during recorded capture. To record the reference video, switch the camera into a MJPEG mode by toggling on the camera mode in the pane.
The video captured by reference cameras can be monitored from the . To view the reference video, select the camera that you wish to monitor, and use the Num 3 hotkey to switch to the reference view. If the camera was and capturing reference videos, 3D assets will be overlaid on top of the reference image.
