Video pixel smoothing

Aim

The Video pixel smoothing option reduces the difference between adjacent pixels prior to detection, by smudging the image, that is, replacing the gray scale value of each pixel with the median of the surrounding pixels.

Background information

How does video pixel smoothing work? In the following example, a bright pixel with gray value 240 is surrounded by darker pixels:

▪If you select Video pixel smoothing= Low, that pixel gets the median value calculated among the 8 nearest pixels plus that pixel itself. In that case the median is 150, so that pixel will look darker.

▪If you specify Video pixel smoothing= Medium, the median is calculated over the 24 nearest pixels plus the pixel itself.

▪If you specify Video pixel smoothing= High, an even bigger group of surrounding pixels is considered.

Procedure

1.In the Detection Settings, under Advanced, open Smoothing.

2.Next to Video pixel smoothing, choose one of the values:

▪None (default): No pixel smoothing. The video image is analyzed for subject detection as it is.

▪Low: Each pixel is blended with the 8 nearest pixels (pixel distance =1).

▪Medium: Each pixel is blended with the 24 nearest pixels (pixel distance 1 or 2).

▪High: Each pixel is blended with the 48 nearest pixels (pixel distance 1, 2 or 3).

Notes

▪Select a moderate Video pixel smoothing value or leave None selected If adjacent pixels in the background are relatively constant. Using more surrounding pixels for the smoothing effect does not bring up better results.

▪Select a high Video pixel smoothing value if adjacent pixels in the background are on average very different. For example, when the cage's bedding material looks grainy. In such cases you need to smooth each pixel using more surrounding pixels to compensate for this variation.

▪A high Video pixel smoothing level requires a significant amount of processor capacity.

▪Using Video pixel smoothing may result in losing information in the video image important for detection. For example, sharp borders of subjects, etc.

▪Pixel smoothing does not affect Color marker tracking. It does affect detecting the body contour in Marker assisted tracking.