ITK reader- VTK Viewer - Qt GUI

We are using itkImageSeriesReader which support different formats DICOM, JPEG, TIFF, PNG to read in a series but size of images should be same. Then itkImageToVTKImageFilter will convert data from itk to vtk image format that we will visualize through VTK+Qt pipeline. In VTK you can try both viewers just by uncomment two lines of vtkImageViewer2 and comment lines of vtkResliceImageViewer.

Application have :

1. main.cpp

2. mainwindow.h

3. mainwindow.cpp

4. mainwindow.ui

5. CmakeLists.txt

Step 1. Copy XML code of ui form into a text editor and save it as mainwindow.ui format. It will create ui.

Step 2. Create headers, cpp and cmake files.

Step 3. Cmake to generate project file, build and run.

Here is code

mainwindow.ui 

<?xml version="1.0" encoding="UTF-8"?>

<ui version="4.0">

 <class>MainWindow</class>

 <widget class="QMainWindow" name="MainWindow">

  <property name="geometry">

   <rect>

    <x>0</x>

    <y>0</y>

    <width>419</width>

    <height>350</height>

   </rect>

  </property>

  <property name="windowTitle">

   <string>MainWindow</string>

  </property>

  <widget class="QWidget" name="centralWidget">

   <widget class="QVTKWidget" name="qVTK1">

    <property name="geometry">

     <rect>

      <x>10</x>

      <y>10</y>

      <width>381</width>

      <height>291</height>

     </rect>

    </property>

    <property name="sizePolicy">

     <sizepolicy hsizetype="Expanding" vsizetype="MinimumExpanding">

      <horstretch>0</horstretch>

      <verstretch>0</verstretch>

     </sizepolicy>

    </property>

   </widget>

  </widget>

  <widget class="QMenuBar" name="menuBar">

   <property name="geometry">

    <rect>

     <x>0</x>

     <y>0</y>

     <width>419</width>

     <height>21</height>

    </rect>

   </property>

   <widget class="QMenu" name="menu_File">

    <property name="title">

     <string>&amp;File</string>

    </property>

    <widget class="QMenu" name="menu_Open">

     <property name="title">

      <string>&amp;Open</string>

     </property>

     <addaction name="actionDICOM_Sequence"/>

    </widget>

    <addaction name="menu_Open"/>

    <addaction name="separator"/>

    <addaction name="actionExit"/>

   </widget>

   <addaction name="menu_File"/>

  </widget>

  <widget class="QToolBar" name="mainToolBar">

   <attribute name="toolBarArea">

    <enum>TopToolBarArea</enum>

   </attribute>

   <attribute name="toolBarBreak">

    <bool>false</bool>

   </attribute>

  </widget>

  <widget class="QStatusBar" name="statusBar"/>

  <action name="actionJPEG">

   <property name="text">

    <string>JPEG</string>

   </property>

  </action>

  <action name="actionDICOM">

   <property name="text">

    <string>DICOM</string>

   </property>

  </action>

  <action name="actionDICOM_Sequence">

   <property name="text">

    <string>DICOM Sequence</string>

   </property>

  </action>

  <action name="actionExit">

   <property name="text">

    <string>Exit</string>

   </property>

  </action>

 </widget>

 <layoutdefault spacing="6" margin="11"/>

 <customwidgets>

  <customwidget>

   <class>QVTKWidget</class>

   <extends>QWidget</extends>

   <header>QVTKWidget.h</header>

   <container>1</container>

   <slots>

    <slot>sopenimage()</slot>

   </slots>

  </customwidget>

 </customwidgets>

 <resources/>

 <connections/>

</ui>

mainwindow.h

#ifndef MAINWINDOW_H

#define MAINWINDOW_H

#include <QMainWindow>

#include "vtkSmartPointer.h"

class vtkImageViewer2;

class vtkResliceImageViewer;

namespace Ui {

class MainWindow;

}

class MainWindow : public QMainWindow

{

    Q_OBJECT

   

public:

    explicit MainWindow(QWidget *parent = 0);

    ~MainWindow();

   

private slots:

    int DICOMseq();

private:

      //vtkImageViewer2 *image_view;

    vtkSmartPointer<vtkResliceImageViewer> image_view;

    Ui::MainWindow *ui;

};

#endif // MAINWINDOW_H

mainwindow.cpp

//Qt

#include "mainwindow.h"

#include "ui_mainwindow.h"

#include<QFileDialog>

#include<QFileInfoList>

#include<QDir>

#include<iostream>

//ITK

#include "itkImage.h"

#include "itkImageSeriesReader.h"

#include "itkImageToVTKImageFilter.h"

//VTK

#include "vtkImageViewer2.h"

#include "vtkResliceImageViewer.h"

#include "vtkRenderWindow.h"

#include "vtkRenderWindowInteractor.h"

#include "vtkRenderer.h"

using namespace std;

MainWindow::MainWindow(QWidget *parent) :

    QMainWindow(parent),

    ui(new Ui::MainWindow)

{

    ui->setupUi(this);

  

      //image_view = vtkImageViewer2::New();

      image_view = vtkSmartPointer<vtkResliceImageViewer>::New();

     

   //Qt Signal slot    

      connect(ui->actionDICOM_Sequence,SIGNAL(triggered()),this, SLOT(DICOMseq()));

      connect(ui->actionExit,SIGNAL(triggered()),this, SLOT(close()));

}

MainWindow::~MainWindow()

{

    delete ui;

}

int MainWindow::DICOMseq()

{

      typedef signed short InputPixelType;//Pixel Type

      const unsigned int InputDimension = 3;//Dimension of image

      typedef itk::Image< InputPixelType, InputDimension > InputImageType;//Image Type

      typedef itk::ImageSeriesReader< InputImageType > ReaderType;//Reader of Image Type

      ReaderType::Pointer reader = ReaderType::New();

      //Replacement of name generator of ITK

      QDir dir("Dir");

      dir=QFileDialog::getExistingDirectory(0,"Select Folder: ");

      QFileInfoList list = dir.entryInfoList(QDir::Dirs| QDir::Files | QDir::NoDotAndDotDot);

            std::vector<std::string> names;

         foreach(QFileInfo finfo, list)

                  {

                        std::string str=dir.path().toStdString().c_str();

                        str=str+"/";

                        names.push_back(str+finfo.fileName().toStdString().c_str());

                  }

      reader->SetFileNames( names );

      //Exceptional handling

      try

      {

            reader->Update();

      }

      catch (itk::ExceptionObject & e)

      {

            std::cerr << "exception in file reader " << std::endl;

            std::cerr << e << std::endl;

            return EXIT_FAILURE;

      }

    /*

     

      You can impliment your Filter here and connect its output to connector below.

     

      */

      //connector to convert ITK image data to VTK image data

      typedef itk::ImageToVTKImageFilter<InputImageType> ConnectorType;

      ConnectorType::Pointer connector= ConnectorType::New();

      connector->SetInput( reader->GetOutput() );//Set ITK reader Output to connector you can replace it with filter

     

      //Exceptional handling

      try

      {

            connector->Update();

      }

      catch (itk::ExceptionObject & e)

      {

            std::cerr << "exception in file reader " << std::endl;

            std::cerr << e << std::endl;

            return EXIT_FAILURE;

      }

      //deep copy connector's output to an image else connector will go out of scope

      //and vanish it will cause error while changing slice

      vtkImageData * image = vtkImageData::New();

      image->DeepCopy(connector->GetOutput());

     

      //set VTK Viewer to QVTKWidget in Qt's UI

      ui->qVTK1->SetRenderWindow(image_view->GetRenderWindow());

      image_view->SetupInteractor(ui->qVTK1->GetRenderWindow()->GetInteractor());

      //Set input image to VTK viewer

      image_view->SetInput(image);

      image_view->SetSlice(image_view->GetSliceMax()/2);

      image_view->GetRenderer()->ResetCamera();

      image_view->Render();

    ui->qVTK1->update();

      return EXIT_SUCCESS;

}

main.cpp

#include <QApplication>

#include "mainwindow.h"

int main(int argc, char *argv[])

{

    QApplication a(argc, argv);

    MainWindow w;

    w.show();

   

    return a.exec();

}

CmakeLists.txt

cmake_minimum_required(VERSION 2.6)

PROJECT(main)

IF(NOT VTK_BINARY_DIR)

FIND_PACKAGE(VTK)

IF(NOT VTK_DIR)

  MESSAGE(FATAL_ERROR "Please set VTK_DIR.")

ENDIF(NOT VTK_DIR)

INCLUDE(${VTK_USE_FILE})

ENDIF(NOT VTK_BINARY_DIR)

FIND_PACKAGE ( ITK)

IF ( ITK_FOUND)

INCLUDE( ${USE_ITK_FILE} )

ENDIF( ITK_FOUND)

SET(QT_QMAKE_EXECUTABLE ${VTK_QT_QMAKE_EXECUTABLE} CACHE FILEPATH "")

SET(QT_MOC_EXECUTABLE ${VTK_QT_MOC_EXECUTABLE} CACHE FILEPATH "")

SET(QT_UIC_EXECUTABLE ${VTK_QT_UIC_EXECUTABLE} CACHE FILEPATH "")

FIND_PACKAGE(Qt4 REQUIRED)

INCLUDE(${QT_USE_FILE})

# Set your files and resources here

SET(Main main.cpp mainwindow.cpp)

SET(MainUI mainwindow.ui)

SET(MainH mainwindow.h)

INCLUDE_DIRECTORIES(

  ${QT_INCLUDE_DIR}

  ${CMAKE_CURRENT_BINARY_DIR}

  ${CMAKE_CURRENT_SOURCE_DIR}

)

QT4_WRAP_UI(UISrcs ${MainUI})

QT4_WRAP_CPP(MOCSrcs ${MainH} )

SOURCE_GROUP("Resources" FILES

  ${MainUI}

)

SOURCE_GROUP("Generated" FILES

  ${UISrcs}

  ${MOCSrcs}

  ${RCS_SOURCES}

)

ADD_EXECUTABLE( main ${Main} ${UISrcs} ${MOCSrcs})

TARGET_LINK_LIBRARIES( main QVTK ${ITK_LIBRARIES}  )