Arena Adjustment

When the experiment lasts several days, even several weeks, it can happen that the camera or the workspace are accidentally moved. In this case, when recording a new test, you may find that the arena defined in the protocol no longer corresponds to the real arena where the animals evolve.

If this case occurs, you must not modify the arena in the protocol because it would disturb all the tests already carried out.

To correct arena misalignment, you can :

•use the automatic adjustment function with position ajdustment marks in the "Arena / Zones" tab of the protocol.

•manually adjust the position of the arena in the current test view.

• adjust the video position in the current video view.

Using the automatic adjustment function is recommended, but requires a hardware modification of the enclosure in which the recordings are made. If such a modification is impossible or if videos have already been made without adjustment marks, it is always possible to perform a manual adjustment before analyzing the video.

In case of manual adjustment :

•If the protocol includes secondary arenas, it is advisable to adjust the video (because the adjustment of the main arena is automatically carried over to the secondary arenas) and then copy this adjustment to the videos recorded under the same conditions.

•If the protocol includes only one arena, you can choose to adjust the video or adjust the arena of the test and copy this adjustment to the tests recorded under the same conditions.

The arena adjustment defines the transformation rules (moving, resizing and rotation) to be applied to the image coming from the camera to match the arena defined in the protocol and the real arena.

For an unanalyzed test :

the position of the arena is determined according to the following rules :

1. If the arena has been adjusted in the "current test" view, this adjustment takes priority and the arena position is the one defined manually.

2. Otherwise, and if the video position is adjusted, the arena position is recalculated according to the video adjustment.

Otherwise, and if position adjustment marks are defined in the "Arena / Zones" tab of the protocol, the psoition of the arena is automatically recalculated based on the position of the marks.

3. Otherwise, the arena position is the one defined in the protocol.

When the test is analyzed :

The arena position is memorized during analysis so that it can be used for display and reports even if the video position is adjusted later.

Note : Before Ethotrack version 5.3, the arena position was not memorized during analysis and the video position was not adjustable. For tests analyzed with a version prior to version 5.3, the arena position used for display and reports is therefore either the position manually adjusted before analysis or the position defined in the protocol.

To adjust the arena for a test :

1.Open the relevant test.

2.In the "Information / General" side panel, click on the button located on the "Arena" line

          to open the "Adjust arena" panel :

3.Select "Manually adjust the position of the arena".

4.Adjust the arena to match the real arena :

• using the buttons .

•or, by moving the arena directly with the mouse on the test image.

•or, using the arrow keys :arrow alone to move the arena; [Shift key]+arrow to resize.

Arena adjustment is possible only if the test has not yet been analyzed.

When the arena position has been adjusted for a test, it is possible to copy this adjustment to other tests. To do this, simply click on the button