This software was written by Ö. Güler and Z. Yaniv. Copyright (c) ISC Insight Software Consortium. All rights reserved. See http://www.igstk.org/IGSTK/project/license.html for details. NOT for clinical use. |
To enable tracking of the tip of a pointer tool we need to calibrate it. The calibration process is straightforward and only requires rotating the tool around a fixed, pivot, point. Any rigid pointer like object can be used as a tool. We have found that a short hexagonal pencil with a blunt tip is the simplest readily available pointer.
To calibrate the pointer tool you will need to follow the two step process described below:
If you haven't done so, perform camera calibration using the provided application.
Print the tracked marker patterns (IGITutorial/Data/TrackedMarkers/markers.pdf), and separate the markers along the dashed lines. Make sure that the internal, black, marker square size is 50mm.
Select the pointer tool's marker from the dropdown menu (match the marker image or id number).
Select the number of transformations to acquire. Note that the more transformations the more accurate the calibration but you will have to pivot the pointer for a longer time (acquiring the default number of transformations, 300, takes about 15s).
Press the "Initialize Tracker" button (shortcut key: [i]). LED light will turn green, indicating success.
Position the pointer tool in the location where you want to perform the calibration and make sure that it is visible by the camera. Press the "Check Camera View" button (shortcut key: [c]). A popup showing the camera view will be displayed. The window is automatically closed after a few seconds. If the tracked marker was visible in the central part of the previous image you can continue to the next step, otherwise move the pointer to a new location and repeat the process.
Press the "Calibrate" button (shortcut key: [space]). You have 5s before data acquisition begins. Start pivoting the pointer around the fixed point until data acquisition is completed. If the calibration is successful the information is saved in a file named "ToolTip.xml" in a subdirectory where the tutorial was installed (IGITutorial/Configuration).
[i] | Initialize tracker |
[c] | Show snapshot from camera |
[space] | Calibrate pointer |
[h] | Show help dialog |
[q] | Quit Application |