[vtkusers] how to _ color_ write on a vtkImageCanvasSource2D ?

[Sebastien_MARAUX]

I would like to draw lines, etc. on a (jpeg read) image data.
I use a vtkimageCanvasSource2D to gain access to the 
image data , but when I read the re exported image as a 
jpeg file, I can only see white drawings.

What do I do wrong ?

snippet : 
/*==============================================*/

 vtkImageData *fond = vtkImageData::New();
 fond->SetDimensions(2048,2048,1);
 fond->SetImageData(jpgReader->GetOutput());
 fond->SetScalarTypeToUnsignedChar();
 fond->SetNumberOfScalarComponents(3);
 fond->SetExtent(jpgReader->GetOutput()->GetExtent());

 vtkImageCanvasSource2D *vicsSIG = vtkImageCanvasSource2D::New();
 vicsSIG->SetScalarTypeToUnsignedChar();
 vicsSIG->SetNumberOfScalarComponents(3);
 vicsSIG->SetExtent(fond->GetExtent());
 vicsSIG->SetDrawColor(0.0,0.0,0.0);
 vicsSIG->FillBox(0,texSize[0],0,texSize[1]);
 vicsSIG->SetDrawColor(255.0,0.0,0.0);
 vicsSIG->FillBox(100,500,100,500);
 
 vicsSIG->SetDrawColor(255.0,255.0,0,0);
 vicsSIG->DrawSegment(0,0,1024,1024);
 vicsSIG->Update();

 vtkJPEGWriter *jpgWriter2=vtkJPEGWriter::New();
 jpgWriter2->SetInput(vicsSIG->GetOutput());
 jpgWriter2->SetFileName("sortie2048.jpg");
 jpgWriter2->SetQuality(95);
 jpgWriter2->ProgressiveOn();
 tPrint("\toutputing texture : sorti2048.jpg\n");

/*==============================================*/

Sebastien MARAUX
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://www.vtk.org/pipermail/vtkusers/attachments/20020605/68792b23/attachment.htm>