VTK 医学图像处理---放大镜/区域放大功能
本博文主要内容为：实现放大镜的源代码；实现思路；具体代码说明。
简介：
放大镜（局部放大）在医学图像处理软件中是一个常用的功能，本博文基于VTK实现放大镜功能，该功能主要涉及到交互和放大镜功能实现，具体实现过程中（源代码中），wxInteractorStyleImage类主要实现左键按下、移动到抬起这个过程中局部图像放大的交互；wxMagnifierAcotor类实现局部图像方法功能的实现和显示。
1 放大镜源代码
Main函数入口和主体在 <021_Magnifier.cpp>文件中，wxInteractorStyleImage类主要实现鼠标的交互功能，wxMagnifierAcotor类实现局部图像方法功能的实现和显示。项目工程组织如下图：
在自己的项目中添加 wxInteractorStyleImage 和 wxMagnifierAcotor 两个类的源码（可以自己新建类，把下面代码拷贝进来，然后修改下文件名称即可），然后将Magnifier.cpp文件中的内容拷贝到自己项目main函数所在文件，就可以直接运行。
1 wxInteractorStyleImage 类源代码
头文件如下：
#ifndef wxInteractorStyleImage_h
#define wxInteractorStyleImage_h
#include "vtkInteractorStyleTrackballCamera.h"
// Motion flags
#define VTKIS_WINDOW_LEVEL 1024
#define VTKIS_SLICE 1025
#define VTKIS_MAGNIFIER 1026 /* 添加放大镜事件 ID */
// Style flags
#define VTKIS_IMAGE2D 2
#define VTKIS_IMAGE3D 3
#define VTKIS_IMAGE_SLICING 4
class vtkImageProperty;
class wxMagnifierAcotor;
class wxInteractorStyleImage : public vtkInteractorStyleTrackballCamera
{
public:
static wxInteractorStyleImage *New();
vtkTypeMacro(wxInteractorStyleImage, vtkInteractorStyleTrackballCamera);
void PrintSelf(ostream& os, vtkIndent indent) override;
virtual void SetMagnifier(wxMagnifierAcotor* pActor);
//@{
/**
* Some useful information for handling window level
*/
vtkGetVector2Macro(WindowLevelStartPosition, int);
vtkGetVector2Macro(WindowLevelCurrentPosition, int);
//@}
//@{
/**
* Event bindings controlling the effects of pressing mouse buttons
* or moving the mouse.
*/
void onm ouseMove() override;
void OnLeftButtonDown() override;
void OnLeftButtonUp() override;
void OnMiddleButtonDown() override;
void OnMiddleButtonUp() override;
void OnRightButtonDown() override;
void OnRightButtonUp() override;
//@}
/**
* Override the "fly-to" (f keypress) for images.
*/
void OnChar() override;
// These methods for the different interactions in different modes
// are overridden in subclasses to perform the correct motion. Since
// they might be called from OnTimer, they do not have mouse coord parameters
// (use interactor's GetEventPosition and GetLastEventPosition)
virtual void WindowLevel();
virtual void Pick();
virtual void Slice();
// Interaction mode entry points used internally.
virtual void StartWindowLevel();
virtual void EndWindowLevel();
virtual void StartPick();
virtual void EndPick();
virtual void StartSlice();
virtual void EndSlice();
virtual void StartMagnifier();
virtual void EndMagnifier();
virtual void Magnifier();
//@{
/**
* Set/Get current mode to 2D or 3D. The default is 2D. In 3D mode,
* it is possible to rotate the camera to view oblique slices. In Slicing
* mode, it is possible to slice through the data, but not to generate oblique
* views by rotating the camera.
*/
vtkSetClampMacro(InteractionMode, int, VTKIS_IMAGE2D, VTKIS_IMAGE_SLICING);
vtkGetMacro(InteractionMode, int);
void SetInteractionModeToImage2D() {
this->SetInteractionMode(VTKIS_IMAGE2D);
}
void SetInteractionModeToImage3D() {
this->SetInteractionMode(VTKIS_IMAGE3D);
}
void SetInteractionModeToImageSlicing() {
this->SetInteractionMode(VTKIS_IMAGE_SLICING);
}
//@}
//@{
/**
* Set the orientations that will be used when the X, Y, or Z
* keys are pressed. See SetImageOrientation for more information.
*/
vtkSetVector3Macro(XViewRightVector, double);
vtkGetVector3Macro(XViewRightVector, double);
vtkSetVector3Macro(XViewUpVector, double);
vtkGetVector3Macro(XViewUpVector, double);
vtkSetVector3Macro(YViewRightVector, double);
vtkGetVector3Macro(YViewRightVector, double);
vtkSetVector3Macro(YViewUpVector, double);
vtkGetVector3Macro(YViewUpVector, double);
vtkSetVector3Macro(ZViewRightVector, double);
vtkGetVector3Macro(ZViewRightVector, double);
vtkSetVector3Macro(ZViewUpVector, double);
vtkGetVector3Macro(ZViewUpVector, double);
//@}
/**
* Set the view orientation, in terms of the horizontal and
* vertical directions of the computer screen. The first
* vector gives the direction that will correspond to moving
* horizontally left-to-right across the screen, and the
* second vector gives the direction that will correspond to
* moving bottom-to-top up the screen. This method changes
* the position of the camera to provide the desired view.
*/
void SetImageOrientation(const double leftToRight[3],
const double bottomToTop[3]);
/**
* Set the image to use for WindowLevel interaction.
* Any images for which the Pickable flag is off are ignored.
* Images are counted back-to-front, so 0 is the rearmost image.
* Negative values can be used to count front-to-back, so -1 is
* the frontmost image, -2 is the image behind that one, etc.
* The default is to use the frontmost image for interaction.
* If the specified image does not exist, then no WindowLevel
* interaction will take place.
*/
virtual void SetCurrentImageNumber(int i);
int GetCurrentImageNumber() { return this->CurrentImageNumber; }
/**
* Get the current image property, which is set when StartWindowLevel
* is called immediately before StartWindowLevelEvent is generated.
* This is the image property of the topmost vtkImageSlice in the
* renderer or nullptr if no image actors are present.
*/
vtkImageProperty *GetCurrentImageProperty() {
return this->CurrentImageProperty;
}
protected:
wxInteractorStyleImage();
~wxInteractorStyleImage() override;
wxMagnifierAcotor* MagnifierAcotor;
int WindowLevelStartPosition[2];
int WindowLevelCurrentPosition[2];
double WindowLevelInitial[2];
vtkImageProperty *CurrentImageProperty;
int CurrentImageNumber;
int InteractionMode;
double XViewRightVector[3];
double XViewUpVector[3];
double YViewRightVector[3];
double YViewUpVector[3];
double ZViewRightVector[3];
double ZViewUpVector[3];
private:
wxInteractorStyleImage(const wxInteractorStyleImage&) = delete;
void operator=(const wxInteractorStyleImage&) = delete;
};
#endif
wxInteractorStyleImage类源代码 具体实现.cpp文件源码如下：
#include "wxInteractorStyleImage.h"
#include "vtkAbstractPropPicker.h"
#include "vtkAssemblyPath.h"
#include "vtkPropCollection.h"
#include "vtkCallbackCommand.h"
#include "vtkMath.h"
#include "vtkObjectFactory.h"
#include "vtkRenderer.h"
#include "vtkRenderWindow.h"
#include "vtkCamera.h"
#include "vtkRenderWindowInteractor.h"
#include "vtkImageSlice.h"
#include "vtkImageMapper3D.h"
#include "vtkImageProperty.h"
#include "wxMagnifierAcotor.h"
vtkStandardNewMacro(wxInteractorStyleImage);
//----------------------------------------------------------------------------
wxInteractorStyleImage::wxInteractorStyleImage()
{
this->WindowLevelStartPosition[0] = 0;
this->WindowLevelStartPosition[1] = 0;
this->WindowLevelCurrentPosition[0] = 0;
this->WindowLevelCurrentPosition[1] = 0;
this->WindowLevelInitial[0] = 1.0; // Window
this->WindowLevelInitial[1] = 0.5; // Level
this->CurrentImageProperty = nullptr;
this->CurrentImageNumber = -1;
this->MagnifierAcotor = nullptr;
this->InteractionMode = VTKIS_IMAGE2D;
this->XViewRightVector[0] = 0;
this->XViewRightVector[1] = 1;
this->XViewRightVector[2] = 0;
this->XViewUpVector[0] = 0;
this->XViewUpVector[1] = 0;
this->XViewUpVector[2] = -1;
this->YViewRightVector[0]