void DataManager::GenerateLookupTable()
{
// compute vtkLookupTable colors for labels, first color is black for background
// rest are pre-calculated by Build() based on the number of labels
double rgba[4]{ 0.05, 0.05, 0.05, HIGHLIGHT_ALPHA };
auto labels = m_labelMap->GetNumberOfLabelObjects();
Q_ASSERT(0 != labels);
m_lookupTable->Allocate();
m_lookupTable->SetNumberOfTableValues(labels + 1);
m_lookupTable->SetTableRange(0, labels);
m_lookupTable->SetTableValue(0, rgba);
auto temporal_table = vtkSmartPointer<vtkLookupTable>::New();
temporal_table->SetNumberOfTableValues(labels);
temporal_table->SetRange(0, labels-1);
temporal_table->Build();
for (unsigned int index = 0; index < labels; ++index)
{
temporal_table->GetTableValue(index, rgba);
m_lookupTable->SetTableValue(index + 1, rgba[0], rgba[1], rgba[2], DIM_ALPHA);
}
}
bool Exporter::exportImageFormat(ImageDataObject & image, const QString & fileName)
{
QString ext = QFileInfo(fileName).suffix().toLower();
vtkSmartPointer<vtkImageWriter> writer;
if (ext == "png")
{
writer = vtkSmartPointer<vtkPNGWriter>::New();
}
else if (ext == "jpg" || ext == "jpeg")
{
writer = vtkSmartPointer<vtkJPEGWriter>::New();
}
else if (ext == "bmp")
{
writer = vtkSmartPointer<vtkBMPWriter>::New();
}
if (!writer)
{
return false;
}
const auto scalars = image.dataSet()->GetPointData()->GetScalars();
if (!scalars)
{
return false;
}
const auto components = scalars->GetNumberOfComponents();
if (components != 1 && components != 3 && components != 4)
{
return false;
}
if (scalars->GetDataType() == VTK_UNSIGNED_CHAR)
{
writer->SetInputData(image.dataSet());
}
else
{
auto toUChar = vtkSmartPointer<ImageMapToColors>::New();
toUChar->SetInputData(image.dataSet());
auto lut = vtkSmartPointer<vtkLookupTable>::New();
lut->SetNumberOfTableValues(0xFF);
lut->SetHueRange(0, 0);
lut->SetSaturationRange(0, 0);
lut->SetValueRange(0, 1);
ValueRange<> totalRange;
for (int c = 0; c < components; ++c)
{
ValueRange<> range;
scalars->GetRange(range.data(), c);
totalRange.add(range);
}
toUChar->SetOutputFormat(
components == 3 ? VTK_RGB :
(components == 4 ? VTK_RGBA :
VTK_LUMINANCE));
toUChar->SetLookupTable(lut);
writer->SetInputConnection(toUChar->GetOutputPort());
}
writer->SetFileName(fileName.toUtf8().data());
writer->Write();
return true;
}