Page History

...

To set perspective there are to be at least three objects of the same size in the scene that is in the camera’s field of view. The perspective will be calibrated by these cameras. Poles, people, etc. can be calibration objects. Calibration objects are not to be on the same line. For higher accuracy they are to be positioned in all frame grounds: foreground, medium shot and background. Though, in some cases this is not obligatory: for instance, if there is no need to detect objects in the background and objects in the foreground are to be detected, then calibration objects are to be positioned in the foreground. The more there are calibration objects, the higher the accuracy of parameters restoration is.

It is also possible to set points on the underlying level and their coordinates in meters (at least 3). This setting is not obligatory. Points setting allow getting track position in absolute coordinates. Points are to be located on one level. Points are not to be on the same line. The more uniformly the points are, the higher the accuracy is. 

If the perspective is to be considered when setting maximum and minimum object size do the following:

1. Go to the Perspective tab (1).
   
2. Set the With perspective settings checkbox checked(2).
3. Click the Stop button to stop playback in the viewing tile (3).
4. Specify the size of calibration object (in meters) in the Object size, m field (4).

5. Set the position of calibration objects on the video image in the viewing tile as follows:

   Info
   title Note.
   Zoom in on the video preview field for more precise positioning of calibration objects. To do that, right-click the video preview while holding the Shift key on the keyboard. The video opens in a separate window, which can be resized by dragging its borders. Close this window after adding all required objects.

   
   

1. Click the Add object button (5).
2. Position the object over the calibration object on the video image (6).

3. Correct the object size by dragging its edges using left mouse button.

   Info
   title Note.
   To delete an object click the  button next to it.

   
   

4. Repeat steps a-c for all calibration objects in the scene.
6. In the Width, m group set the maximum and minimum width of detected object (in meters) in the From (7) and To (8) fields (8).
7. In the Height, m group set the maximum and minimum height of detected object (in meters) in the From (9) and To (10) fields.

   If required set points on the background as follows:

   Info
   title Note.
   Zoom in on the video preview field for more precise positioning of points. To do that, right-click the video preview while holding the Shift key on the keyboard. The video opens in a separate window, which can be resized by dragging its borders. Close this window after adding all points.

8. Click the New point button (11).
9. Position a point on the video image (12).
10. Click the Image Removed button. The Position, m dialog box appears.

Set the point position in meters and click OK (12).

Info
title Note.
To delete a point click the Image Removed button next to it.

Repeat steps a-d for all required points.
11. To save the changes, click the Apply button.

...