[vtkusers] Image blending using a lookup table

[Anka Kochanowska]

Hi!
I have found somewhere (at Kitware site?)  the following example -
TestThinPlateWarp:

#include "vtkImageGridSource.h"
#include "vtkLookupTable.h"
#include "vtkImageMapToColors.h"
#include "vtkBMPReader.h"
#include "vtkImageBlend.h"
#include "vtkPoints.h"
#include "vtkThinPlateSplineTransform.h"
#include "vtkImageReslice.h"
#include "vtkSmartPointer.h"
#include "vtkDataObject.h"
#include "vtkRenderer.h"
#include "vtkRenderWindow.h"
#include "vtkRenderWindowInteractor.h"
#include "vtkInteractorStyleTerrain.h"
#include "vtkImageMapper.h"
#include "vtkActor2D.h"

// warp an image with a thin plate spline

int main(int argc, char** argv)
{
    char filename[256];
    const char *temp=getenv("VTK_DATA_ROOT");
    if ( ! temp )
    {
        cerr << "ERROR: Please define environment variable VTK_DATA_ROOT\n";
        return 0;
    }
    strcpy(filename,temp);
    strcat(filename,"Data/masonry.bmp");
    // first, create an image to warp
    vtkSmartPointer< vtkImageGridSource > imageGrid = vtkSmartPointer<
vtkImageGridSource >::New();
    imageGrid->SetGridSpacing( 16, 16, 0 );
    imageGrid->SetGridOrigin( 0, 0, 0 );
    imageGrid->SetDataExtent( 0, 255, 0, 255, 0, 0 );
    imageGrid->SetDataScalarTypeToUnsignedChar();

    vtkSmartPointer< vtkLookupTable > table = vtkSmartPointer<
vtkLookupTable >::New();
    table->SetTableRange( 0, 1 );
    table->SetAlphaRange( 0.0, 1.0 );
    table->SetHueRange( 0.15, 0.15 );
    table->SetSaturationRange( 1, 1 );
    table->SetValueRange( 0, 1 );
    table->Build();

    vtkSmartPointer< vtkImageMapToColors > alpha = vtkSmartPointer<
vtkImageMapToColors >::New();
    alpha->SetInputConnection( imageGrid->GetOutputPort() );
    alpha->SetLookupTable( table );

    vtkSmartPointer< vtkBMPReader > reader = vtkSmartPointer<
vtkBMPReader >::New();
    reader->SetFileName(filename);
    reader->Update();

    vtkSmartPointer< vtkImageBlend > blend = vtkSmartPointer<
vtkImageBlend >::New();
    blend->AddInput( 0, (vtkDataObject*)reader->GetOutput() );
    blend->AddInput( 0, (vtkDataObject*)alpha->GetOutput() );

    // next, create a ThinPlateSpline transform

    vtkSmartPointer< vtkPoints > p1 = vtkSmartPointer< vtkPoints >::New();
    p1->SetNumberOfPoints( 8 );
    p1->SetPoint( 0, 0, 0, 0 );
    p1->SetPoint( 1, 0, 255, 0);
    p1->SetPoint( 2, 255, 0, 0 );
    p1->SetPoint( 3, 255, 255, 0 );
    p1->SetPoint( 4, 96, 96, 0 );
    p1->SetPoint( 5, 96, 159, 0 );
    p1->SetPoint( 6, 159, 159, 0 );
    p1->SetPoint( 7, 159, 96, 0 );

    vtkSmartPointer< vtkPoints > p2 = vtkSmartPointer< vtkPoints >::New();
    p2->SetNumberOfPoints( 8 );
    p2->SetPoint( 0, 0, 0, 0 );
    p2->SetPoint( 1, 0, 255, 0 );
    p2->SetPoint( 2, 255, 0, 0 );
    p2->SetPoint( 3, 255, 255, 0);
    p2->SetPoint( 4, 96, 159, 0 );
    p2->SetPoint( 5, 159, 159, 0 );
    p2->SetPoint( 6, 159, 96, 0 );
    p2->SetPoint( 7, 96, 96, 0 );

    vtkSmartPointer< vtkThinPlateSplineTransform > transform =
vtkSmartPointer< vtkThinPlateSplineTransform >::New();
    transform->SetSourceLandmarks( p2 );
    transform->SetTargetLandmarks( p1 );
    transform->SetBasisToR2LogR();
    // you must invert the transform before passing it to vtkImageReslice
    transform->Inverse();

    vtkSmartPointer< vtkImageReslice > reslice = vtkSmartPointer<
vtkImageReslice >::New();
    reslice->SetInputConnection( blend->GetOutputPort() );
//    reslice->SetResliceTransform( transform );
    reslice->SetInterpolationModeToLinear();
    vtkSmartPointer< vtkImageMapper > map = vtkSmartPointer<
vtkImageMapper >::New();
    map->SetInput( reslice->GetOutput() );
    map->SetColorWindow( 255.0);
    map->SetColorLevel( 127.5 );
    map->SetZSlice( 0 );
    vtkSmartPointer< vtkActor2D > act = vtkSmartPointer< vtkActor2D >::New();
    act->SetMapper( map );
    act->SetPosition( 0.0, 0.0 );

    vtkSmartPointer< vtkRenderer > renderer = vtkSmartPointer<
vtkRenderer >::New();
    renderer->AddActor( act );
    vtkSmartPointer< vtkRenderWindow > window = vtkSmartPointer<
vtkRenderWindow >::New();
    window->SetSize( 640, 480 );
    window->AddRenderer(renderer);
    vtkSmartPointer< vtkRenderWindowInteractor > interactor =
vtkSmartPointer< vtkRenderWindowInteractor >::New();
    interactor->SetRenderWindow(window);
    vtkSmartPointer< vtkInteractorStyleTerrain > style =
vtkSmartPointer< vtkInteractorStyleTerrain >::New();
    interactor->SetInteractorStyle( style );
    interactor->Initialize();
    interactor->Start();
	return 0;
}

_____________________________
Anka



On Wed, Mar 3, 2010 at 11:08 AM, "Tim Hütz (VTK)" <vtk at huetz.biz> wrote:
> Hey David,
>
> of course I can do this. I'll will extract the corresponding code
> parts out of my project and will build a simple example for using
> the vtkImageMapToColors class. Should I submit this sample to this
> list (with all required files)?
>
> Best regards,
> Tim
>
> David Doria schrieb:
>> On Wed, Mar 3, 2010 at 10:52 AM, "Tim Hütz (VTK)" <vtk at huetz.biz
>> <mailto:vtk at huetz.biz>> wrote:
>>
>>     Hey David,
>>
>>     thank you for your fast reply. With the vtkImageMapToColors class,
>>     it works
>>     perfectly. Thanks a lot.
>>
>>
>>     Best regards,
>>     Tim
>>
>>
>> Tim,
>>
>> There is no example that uses vtkImageMapToColors. Would you be
>> interested in adding one? At the very least, could you send a small
>> sample code to the mailing list and I'll make one?
>>
>> Thanks,
>>
>> David
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