Vicon MX is the world’s first and only system that uses full grayscale to capture passive markers.  Vicon MX never throws data away, using all available measurements to ensure that data quality is as high as possible.

GRAYSCALE KEY BENEFITS
• Using full grayscale is the most accurate way of calculating the center of a marker.
• Grayscale images of overlapping or partially occluded markers are sent to the capture PC, which uses more powerful algorithms to resolve marker centers.
• Grayscale marker images are displayed in software – an essential tool for setting up and optimizing your system.

SO WHAT IS GRAYSCALE?
A grayscale image is recorded by the MX camera’s sensor, which has a given pixel resolution, for example the MX-F40’s 2352 x 1768 which is more than 4 million pixels. Each pixel is light sensitive, and measures the amount of light that hits it during a given period of time. The MX cameras have strobes that emit flashes of light between 50 and 2000 times a second, which is reflected back off the markers and focused through the lens onto the sensor, creating circular bright spots. As soon as the strobe turns off, the camera scans the sensor and passes the full grayscale image to the camera’s on-board processors.

ON-BOARD PROCESSING
The main difference between MX cameras and competitors’ cameras is the way the grayscale images are processed. Uniquely, the MX camera processes the entire image with full grayscale using its superior built-in processing capabilities. Other cameras use grayscale only to determine where the edge of a marker is, which is a far simpler task – all the grayscale information from pixels that are deemed not to be edges is thrown away. Vicon MX cameras use all the information to determine the center of the marker, and if it cannot be resolved (for example if the marker is partially occluded); the whole image is sent to the capture PC for further processing.

EXTREME ACCURACY
Not only do the MX cameras use all the grayscale information available, the algorithm used is also extremely accurate and able to determine the center of a marker to 1/256th of a sensor pixel. This corresponds to an MX-F40 sub-pixel accuracy of 1/600,000 in the horizontal direction and 1/440,000 in the vertical direction. In practice, this means that if a camera “sees” a marker where the field of view is 5 meters wide, it is able to detect a movement of only 0.01 millimeters. If you move the camera closer, the spatial resolution is even higher.

WHY THROW DATA AWAY?
In real life capture situations, markers occasionally overlap or become partially occluded. If this happens, other systems using simple edge detection will throw valuable information away. In contrast, the MX cameras will send the entire grayscale marker image to the capture PC. There are two great benefits: first and foremost, the superior number crunching capabilities of a PC can be used to resolve the marker overlap. The other benefit is that you are able to see exactly what’s going on and don’t have to wonder why a marker center fails to appear.

SEEING IS BELIEVING
Vicon MX cameras have the ability to upload all marker images (rather than just the ones that overlap) to the capture PC. This unique feature is useful from a setup and optmization point of view as it allows you to see exactly what the camera sees - an essential tool when setting up the system.

Grayscale - can you see what we see?