video feature based optical camera tracking system

Specifications

working principle

purely video based
You just feed the video of your broadcast camera to the Viotrack Video Processor, that's it. Then VioTrack recognizes the unique markers, calculates the camera pose and sends the tracking data to the Graphics Renderer.
 

video based, like version S1,
but the zoom and focus position is processed to determine the virtual lens parameters. Now just the pose of the camera has to be determined through image processing. The zoom and focus data are received through the internal interface of the lens manufacturer or additional lens encoders.

video based, like version S2,
but an additional sensor camera always detects VioTrack's unique markers.
Now the camera lens can even totally zoom in where no markers are seen in the TV picture, but the video features are still be detected by the sensor camera.

S3 uses two types of markers: one for chroma key Markers can be placed at the green/blue box or at to the studio ceiling.

 

 

 

OR

type of absolute markers

painted with the help of stencils on the green/blue box, the back wall or floor in a keyable color

painted with the help of stencils on the green/blue box, the back wall or floor in a keyable color

painted with the help of stencils on the green/blue box, the back wall or floor in a keyable color
or
retroreflective markers for infrared light to be positioned at the ceiling, lights or wall of the studio

 

degrees of freedom

VioTrack S1 enables the camera to pan and tilt and to change the zoom and the focus.
 

In addition to VioTrack S1, it enables the camera to do basic position moves on air.

All camera axis can be moved freely, even the zoom and focus

limitations

Zoom and focus have to be adjusted that markers can always be seen within the camera picture.
The position of the tripod is fixed. New tripod locations can easily be adjusted off air. To get rid of this limitation, please see VioTrack S2.

 

zoom and focus have to be adjusted that the markers can always be seen within the camera picture.
To get rid of this limitation, please see VioTrack S3.

The sensor camera has to see the markers, therefore only extreme movements e.g. like a 360 degrees tilt do not work

VioTrack Video Processor

 

any commercially available PC with Intel Quad Core with 4 CPUs
PCI Express 4 lane slot for video card
Different models like Workstation, Small Form Factor (SFF) or 19” rack mount available

 

video input

video card supports 8/10-bit uncompressed SD/HD video streams according to SMPTE-259/292/296

 

reference signal

Not needed – system synchronizes on video input signal

 

Lens data

receives serial data from TV lens:
Canon (RS 485) or Fujinon (RS 232) Virtual protocol types are supported
If serial lens data interface is not available, additional encoders can be mounted to the lens

 

data output

Network connection:
10/100/1000 Mbit Ethernet (IEEE 802.3)
UDP/IP-protocol (RFCs 793, 791 und 768)

The Xync camera tracking interface is employed as the interface protocol.

 

Technology

Real-time algorithm uses video feature points within the video image

Instead of measuring the single axis of the support system, calibrating and calculating the final position of the camera, VioTrack determines the position of the virtual objects directly.
Optical absolute markers are placed within the studio and are building the basis for all calculations. Each marker can be identified by VioTrack through it's unique pattern.

The markers are painted with a slightly different green or blue tone than the standard background, therefore they can easily be keyed by the Chroma Keyer and do not appear in the final image. Alternatively you can fix retroreflective markers at the studio ceiling or wall. Together with dedicated infrared lighting and sensor camera you can work independent of the studio lighting or green/blue box. So even Augmented Reality applications are possible.

 

S1 Determines the exact pose for Virtual Graphics within the video image
Within the video picture of the broadcast camera, VioTrack determines the correct position of these image feature points in 3D and sticks the virtual objects at the place of those markers or there surrounding.

S2 Determines the exact camera  pose even for moving cameras
Within the video picture of the broadcast camera, VioTrack determines the correct position of these image feature points in 3D and sticks the virtual objects at the place of those markers or there surrounding. Because it uses the data form zoom and focus of the TV lens, it can precisely determine the 3D position and orientation of the camera while moving, even if the marker plane is just a flat 2D screen.

S3 Determines the exact camera  pose about full zoom range
Besides the camera video picture, VioTrack S3 employes a dedicated sensor camera to observe the scenery. This sensor camera is rigidly attached to the TV camera and follows every movement. Even if the TV camera lens fully zooms in and the video features could not be recognized any longer in the TV camera picture, the sensor camera still observes the relevant features. Therefore all camera and lens axis can freely be moved.

Instead of chroma key markers at the green/blue screen you can fix retroreflective markers at the studio ceiling or wall. Together with dedicated infrared lighting and the sensor camera pointing upwards to the markers you can work independent of the studio lighting or a green/blue box. So even Augmented Reality applications are possible.

 

Real-time algorithm uses the camera video picture for perfect matching results
The camera video signal is building the basis for all calculations. This causes a perfect matching between real objects and virtual graphics. Depending on the VioTrack version, the actual lens parameters are processed in addition (VioTrack S2 and S3) and even a sensor camera is applied (VioTrack S3).

unique markers for absolute positioning
The employed markers guarantee a reliable and absolute result for the positioning of the graphics. Each marker contains a unique pattern.  After the self-calibration, the 3D position of each marker is well known by the software.

Therefore whenever you start the tracking, it will immediately find the absolute position of the camera and therefore the Virtual Graphics. There is no need for further adjustments.

various markers for various jobs
The size of the markers, their pattern, their number of dots, their color, everything can be changed to adapt them to the specific job. While just a few smaller markers are needed for a simple screen, many markers are used for a 1.000 sqrm green box with four walls.

Automated self-calibration of markers
First you draw, paint or stick the markers in any order (!) and any position to the wall, floor or ceiling. Then a camera is used to just take some snapshots of these markers from various angles. That’s it!

The calibration software automatically calculates the 3D position of each marker and stores this data for the usage with the real-time camera tracking.

 

  • Virtual Studios
     

  • Virtual Depth Screen
     

  • Virtual Backlots
     

  • Augmented Reality

Applications

Especially through VioTrack's three different versions it can easily be adapted to various formats and applications. Your imagination is the limit. Therefore here we just name a few:

Virtual Backplane
Just a short teaser or the weather forecast? Or a large background for the next game show? A virtual Backplane replaces a real 2D background, screen or video wall? A perfect job for VioTrack.

Virtual Depth Screen
Crossing the limits of a regular video screen, backdrop or projection by showing 2D or 3D objects which are leaving the picture frame in all three dimensions. While using VioTrack and a 3D graphics renderer you achieve ultimate picture quality, a stunning 3D effect and no limitations for the size of your screen.  Works even for multiple screens in various positions.

Virtual Studios
A rendered 3D scenery replaces the blue or green box. With VioTrack you can show your audience the studio from any angle.

Augmented Reality
You do have a real scenery and just want to show virtual objects at specific spots? A clever arrangement of VioTrack can help you even there.

  • optical camera tracking using variable markers
     
  • two different versions for any application and budget
     
  • free camera movement for all camera axis
     
  • no dedicated support system needed

Key features

Camera tracking systems determine the pose of the employed camera and support system in order to render the virtual image from the same perspective as the real camera. Traditional tracking systems require new equipment with external sensors at each axis of the individual support system and precise calibrations.
In opposite to this, VioTrack uses image feature points within the video picture of the camera to place the virtual graphics exactly at their desired position within the set. VioTrack’s unique markers are placed everywhere the action is needed, identified by image processing and located in 3D. As the stunning result, Virtual graphics are precisely sticking to the set.

VioTrack is designed in two different versions to fit your desired freedom of camera movement and budget best. Choose the most cost effective VioTrack S1 for free camera movements for all axis in an area of about 2 x 2m or VioTrack S2  for an unlimited tracking area.

 

video based camera tracker works independent of the camera support system
VioTrack does not rely on sensor data from any other devices or support systems, like encoded pan-tilt heads, inertial sensors etc. Therefore the tracked camera can be used for various support systems. Just lift your broadcast camera and mount it to the next support system and it is immediately ready to use. 

works with every camera, lens and support system, just retrofit
Viotrack works with every type of camera, any type of lens and any support system. Even better, you can keep your existing equipment and just retrofit with Viotrack. This is the most affordable solution to step into Virtual applications.

get rid of standard 2D video walls or projection systems and use a 3D Virtual Depth Screen
All video walls, screens or projections are just showing a flat 2D image. But with VioTrack a Virtual Depth Screen creates stunning 3D depth effects where 3D sceneries can be seen from different camera angles and the content leaves the picture frame. Even if your backplane is just flat, the Virtual Graphics blasts your standard screen plane and will occur behind and in front the standard screen, inside or even outside this frame.

any size and shape, even large backplanes or Virtual Studios with no extra costs
For VioTrack it does not matter if you are using a small screen or the whole studio walls. The same systems tracks any sized green or blue screen.
Independet of the size of your screen you always achieve an optimum picture quality with a higher contrast than with a projection, a higher resolution than a video wall and you just need one renderer, you can even zoom in, no borders between monitors, no reflections

open real-time data transfer interface to any Virtual Graphics system
Works with every Virtual Graphics software thanks to the open interface. The complete camera tracking data are sent to the network to an unlimited number of graphics machines.

 

 

VioTrack S1

Designed for free camera movements for all axis. Restricted to a tracking area of 2 x 2 meters.
A dedicated sensor camera which is rigidly attached to the TV camera and observes the scene. The sensor camera always has the markers in view and determines the 3D position and orientation of the camera precisely. Now the camera can be moved with the help of a pedestal, a crane or even just your shoulder, any support system is possible. In additon, thanks to the independent sensors for zoom and focus of the TV camera you can even use the zoom and focus while moving in 3D space.

The individual feature markers can be set anywhere in the studio, the back wall, the studio ceiling or the floor. The individual calibration of the single markers position establishes a reliable set-up for the camera tracking.

 

VioTrack S2

Designed for free camera movements for all axis. For an unlimited tracking area for any studio size.
A dedicated sensor camera which is rigidly attached to the TV camera and observes the scene. The sensor camera always has the markers in view and determines the 3D position and orientation of the camera precisely. Now the camera can be moved with the help of a pedestal, a crane or even just your shoulder, any support system is possible. In additon, thanks to the independent sensors for zoom and focus of the TV camera you can even use the zoom and focus while moving in 3D space.

The individual feature markers can be set anywhere in the studio, the back wall, the studio ceiling or the floor. The individual calibration of the single markers position establishes a reliable set-up for the camera tracking.

 

 

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