Quick Start

Prerequisites

• ITK ≥ 5.4

• CMake ≥ 3.20

• A C++17-capable compiler: GCC ≥ 12, Apple Clang ≥ 15, or MSVC 2022

• trx-cpp is vendored and fetched automatically; no separate installation is needed

Building as an ITK Remote Module

To build TractographyTRX as part of ITK, enable the module when configuring ITK:

cmake -S ITK \
      -B ITK-build \
      -DModule_TractographyTRX=ON \
      -DITK_WRAP_PYTHON=OFF
cmake --build ITK-build

This is the standard path for production use. The built module will be available to any project that links against the resulting ITK installation.

Building Standalone

If ITK is already installed, TractographyTRX can be built against it directly:

cmake -S . -B build -DITK_DIR=/path/to/ITK-build
cmake --build build

Verifying the Installation

After building, run the test suite to confirm everything works:

ctest --test-dir build -V

All tests should pass. The key test is itkTrxReadWriteTest, which validates round-trip write and read-back integrity.

Hello World

The following program opens a TRX file and prints its streamline count. It requires ITK built with TractographyTRX enabled:

#include "itkTrxFileReader.h"
#include "itkTrxStreamlineData.h"
#include <iostream>

int main(int argc, char * argv[])
{
  if (argc < 2)
  {
    std::cerr << "Usage: hello_trx <input.trx>\n";
    return EXIT_FAILURE;
  }

  auto reader = itk::TrxFileReader::New();
  reader->SetFileName(argv[1]);
  reader->Update();

  auto data = reader->GetOutput();
  std::cout << "Streamlines: " << data->GetNumberOfStreamlines() << "\n";
  std::cout << "Vertices:    " << data->GetNumberOfVertices()    << "\n";

  return EXIT_SUCCESS;
}

Link against the TractographyTRX and ITK Common module targets in your CMakeLists.txt:

find_package(ITK REQUIRED COMPONENTS ITKCommon TractographyTRX)
itk_generate_factory_registration()

add_executable(hello_trx hello_trx.cxx)
target_link_libraries(hello_trx
  PRIVATE
    ITK::ITKCommonModule
    ITK::TractographyTRXModule
)