TrackIR 5 does have the raw and reporting resolution we claim—otherwise we would not claim it. We respect our customers and are not misleading them with our marketing. Our measurements are based on engineering and physical testing.
Reporting resolution is not the same as raw sensor resolution, so we’re not implying that TrackIR 5 is a gigapixel camera. Neither are our numbers the result of software interpolation. In fact, TrackIR is not even a “camera” in the way you are describing, and its function is different than standard camera imaging. We’re not out to capture what an image looks like. We’re looking for the location of marker centroids.
When we describe sub-pixel resolution, we are defining how accurately we can discern the center of the marker in terms of pixels. It is a unit of measurement. Although our raw sensor size is 640 x 480, TrackIR 5 can actually measure movement that is much smaller than a pixel—as small as 1/150th of a pixel. Spread that across 640 pixels and what do you get? A range of 96,000 detectable object locations.
That’s not the same as saying that we have a 6 gigapixel camera. If you have a ruler with 12 inches on it, and you measure an object that falls in between the inch marks, accurate measurement requires sub-inch units. The principle is the same with our grayscale image processing. The center of a marker usually lies between two adjacent pixel locations. We use sub-pixel analysis to accurately find that center down to 1/150th of a pixel's accuracy. Clearly we do not transmit the entire image. The entire benefit of having a TrackIR is that we make a custom, purpose-built product for tracking markers. It processes the image on-board at 120 FPS, which is a very large amount of data, and then only transmits the relevant information to the PC. Thus, there is very little load on the PC.
Consumer digital cameras used for photography sometimes use sub-pixel resolution when creating a viewable image, in which case adjacent pixels may be interpolated. That is not what we are doing—we have a grayscale imager, and we don’t use a Bayer pattern. Rather, we are describing how our new processing has advanced the effective resolution of finding a marker and reporting its center to the software. There are many ways to do this, and our method has achieved the resolution we report.
If you don't believe our figures, please feel free to test them yourself with our free OptiTrack SDK and a micrometer.