SpyGRT 0.1

Toolkit to build SGRT applications

SpyGRT

SpyGRT, or Surface Guided Radiotherapy Toolkit in Python is a toolkit that allows fast development of novel surface guidance applications for radiotherapy.

SpyGRT allows easy:

• Operation of the depth camera (current model is Intel Realsense D415)
• Calibration of multiple cameras into the same external frame of reference
• Tracking of motion using an ICP workflow

Getting Started

Installing SpyGRT using pip

The preferred method for installing SpyGRT is to use pip. This will download all the required packages, however a list of prerequisites and where to find them are listed in the next section in case you prefer to build them from source.

Steps to installing SpyGRT with pip

1. Clone the SpyGRT GitHub repo
2. Open a command prompt
3. Navigate to the SpyGRT folder (not the embedded spygrt folder)
4. Enter the following pip command

pip install -e . 

5. You should now be able to run SpyGRT

Prerequesites

1. Intel RealSense SDK2.0

If you want to build from source, installation instructions available here. The code has currently only been tested up to release version 2.5.0 but should work with more recent releases.

2. Open3D library v.0.15.0 or later

If you want to build it from source, full release available here and instructions to compile it yourself are available here.

3. OpenCV

Full release available here, if you prefer to build it from source.

4. Numpy

More Information available here

Working Examples

The example folder contain three examples that illustrate how to use the basic functions of SpyGRT. More instructions are located in that folder.

Depth Sensor

SpyGRT is currently built to use Intel RealSense D415 stereo depth sensors for capturing depth data. However, it should be possible to modify the stream module to work with any commercial depth sensors that have a python API.

Intel RealSense Viewer

While SpyGRT contains the required code for real-time SGRT and analysis of prior recordings, it cannot currently be used to create new recordings. We suggest installing the free realsense-viewer app available here if you want to create your own recordings.

Calibrations Boards

Default SpyGRT Calibration Board

SpyGRT uses a checkerboard to calibrate multiple cameras. By default, it assumes that the checkboard has 5 rows, 8 columns, and that the length of the sides of each square is 4.3 centimeters. If you want to print the default checkerboard, you can find it in a powerpoint file located in the SampleData folder. This file should be printed on an A3 paper to get the accurate dimensions.

Custom Calibration Board

Any checkerboard can be use to calibrate cameras with SpyGRT. If you want to use a custom checkerboard, you will need to change the following default variables in calibration.py

1. DEFAULT_ROW: Number of rows in the custom calibration board.
2. DEFAULT_COLUMN: Number of columns in the custom calibration board
3. DEFAULT_SQUARE_SIZE: Length in meters of the sides of a square in the custom calibration board

Tracking with SpyGRT

Calibration files are necessary to use the SpyGRT for tracking. By default, SpyGRT will look for calibration files ../Calibrations/. If you want to change this path, you must change the following constant in tracker.py

• CALIBRATION_FOLDER

Author

Youssef Ben Bouchta