# Advanced detection settings: Subject size (one subject per arena)

Aim

To set a minimum and a maximum apparent size of the subject to prevent objects like droppings or large reflections from being detected during tracking.

This topic applies to

All experiments set to:

▪Number of Subjects per Arena: 1

▪Body point detection technique: Contour-based

Procedure

1.In the Detection Settings window, locate the Subject Size.

2.When EthoVision XT finds the subject, check the value under Current. The Current value gives an idea of the detected body size in pixels.

3.Click the Edit button and set the Minimum and Maximum subject sizes. Objects that have the same color as the animal, but are smaller than the Minimum or larger than Maximum size, are not tracked.

You are now ready to acquire data.

Notes

▪The term size here means surface area in video pixels, not length or screen pixels. Enlarging the Video window does not change the subject's size in video pixels.

▪Objects whose size is outside the size range, are shown in the color under Noise (default: orange; see View the detection features on the video window).

▪Click the video icon next to Subject Size and watch the video tutorial.