/// <summary>
/// Gets a 2D slice from the 3D data.
/// </summary>
/// <param name="volume">Full 3D data.</param>
/// <param name="sliceN">Number of slice to be selected.</param>
/// <param name="axis">Axis on which selection will be made.</param>
/// <returns></returns>
public static vtkImageData volumeSlicer(vtkImageData volume, int[] sliceN, int axis)
{
//Initialize VOI extractor and permuter.
//Permuter will correct the orientation of the output image
vtkExtractVOI slicer = vtkExtractVOI.New();
vtkImagePermute permuter = vtkImagePermute.New();
//Connect data to slicer
slicer.SetInput(volume);
slicer.Update();
//Get data dimensions
int[] dims = slicer.GetOutput().GetExtent();
//Get slice
//Coronal plane
if (axis == 0)
{
//Set VOI
slicer.SetVOI(sliceN[0] - 1, sliceN[0], dims[2], dims[3], dims[4], dims[5]);
slicer.Update();
//Permute image (not necessary here)
permuter.SetInputConnection(slicer.GetOutputPort());
permuter.SetFilteredAxes(1, 2, 0);
permuter.Update();
}
//Transverse plane YZ
if (axis == 1)
{
//Set VOI
slicer.SetVOI(dims[0], dims[1], sliceN[1] - 1, sliceN[1], dims[4], dims[5]);
slicer.Update();
//Permute image
permuter.SetInputConnection(slicer.GetOutputPort());
permuter.SetFilteredAxes(0, 2, 1);
permuter.Update();
}
//Transverse plane, XZ
if (axis == 2)
{
//Set VOI
slicer.SetVOI(dims[0], dims[1], dims[2], dims[3], sliceN[2] - 1, sliceN[2]);
slicer.Update();
//Permute image
permuter.SetInputConnection(slicer.GetOutputPort());
permuter.SetFilteredAxes(0, 1, 2);
permuter.Update();
}
//slicer.Update();
//Return copy of the slice
return(permuter.GetOutput());
}
/// <summary>
/// Converts 3D byte array to vtkImageData.
/// </summary>
/// <param name="data">Input array.</param>
/// <param name="orientation">Data orientation as a list of axes (0-2)</param>
/// <returns>Converted array.</returns>
public static vtkImageData byteToVTK(byte[,,] data, int[] orientation = null)
{
//Get input dimensions
int[] dims = new int[] { data.GetLength(0), data.GetLength(1), data.GetLength(2) };
//Create VTK data for putput
vtkImageData vtkdata = vtkImageData.New();
//Character array for conversion
vtkUnsignedCharArray charArray = vtkUnsignedCharArray.New();
//Pin byte array
GCHandle pinnedArray = GCHandle.Alloc(data, GCHandleType.Pinned);
//Set character array input
charArray.SetArray(pinnedArray.AddrOfPinnedObject(), dims[0] * dims[1] * dims[2], 1);
//Set vtkdata properties and connect array
//Data from char array
vtkdata.GetPointData().SetScalars(charArray);
//Number of scalars/pixel
vtkdata.SetNumberOfScalarComponents(1);
//Data extent, 1st and last axis are swapped from the char array
//Data is converted back to original orientation
vtkdata.SetExtent(0, dims[2] - 1, 0, dims[1] - 1, 0, dims[0] - 1);
//Scalar type
vtkdata.SetScalarTypeToUnsignedChar();
vtkdata.SetSpacing(1.0, 1.0, 1.0);
vtkdata.Update();
pinnedArray.Free();
//Return vtk data
if (orientation == null)
{
return(vtkdata);
}
else
{
vtkImagePermute permuter = vtkImagePermute.New();
permuter.SetInput(vtkdata);
permuter.SetFilteredAxes(orientation[0], orientation[1], orientation[2]);
permuter.Update();
return(permuter.GetOutput());
}
}
/// <summary>
/// Scans the input mask slice by slice and selects the largest binary component of each slice.
/// Return cleaned mask as vtkImageData
/// </summary>
/// <param name="input"></param>
/// <param name="extent"></param>
/// <param name="threshold"></param>
/// <param name="axes"></param>
/// <returns></returns>
public static vtkImageData FalsePositiveSuppresion(vtkImageData input, int[] extent, double threshold, int axis, double scale = 1.0)
{
//Slice extractor
vtkExtractVOI slicer = vtkExtractVOI.New();
//Permuter
vtkImagePermute permuter = vtkImagePermute.New();
//List of outputs
List <byte[, , ]> outputs = new List <byte[, , ]>();
//List of output orientations
List <int[]> orientations = new List <int[]>();
//vtkImageData size
int[] full_extent = input.GetExtent();
//Set range for slices
int start = 0, stop = 0;
int[] size = new int[2];
int[] outextent = new int[4];
if (axis == 0)
{
start = extent[0];
stop = extent[1];
size = new int[] { extent[3] - extent[2] + 1, extent[5] - extent[4] + 1 };
outextent = new int[] { extent[2], extent[3] + 1, extent[4], extent[5] + 1 };
}
if (axis == 1)
{
start = extent[2];
stop = extent[3];
size = new int[] { extent[1] - extent[0] + 1, extent[5] - extent[4] + 1 };
outextent = new int[] { extent[0], extent[1] + 1, extent[4], extent[5] + 1 };
}
if (axis == 2)
{
start = extent[4];
stop = extent[5];
size = new int[] { extent[1] - extent[0] + 1, extent[3] - extent[2] + 1 };
outextent = new int[] { extent[0], extent[1] + 1, extent[2], extent[3] + 1 };
}
//Temporary array for output
byte[,,] output = new byte[full_extent[1] + 1, full_extent[3] + 1, full_extent[5] + 1];
int[] outsize = new int[] { size[0], size[1], stop - start + 1 };
//Loop over current axis
for (int k = start; k < stop; k++)
{
byte[] bytedata = new byte[size[0] * size[1]];
//Select slice
if (axis == 0)
{
slicer.Dispose();
slicer = vtkExtractVOI.New();
slicer.SetInput(input);
slicer.SetVOI(k, k, extent[2], extent[3], extent[4], extent[5]);
slicer.Update();
permuter.Dispose();
permuter = vtkImagePermute.New();
permuter.SetInput(slicer.GetOutput());
permuter.SetFilteredAxes(1, 2, 0);
permuter.Update();
}
if (axis == 1)
{
slicer.Dispose();
slicer = vtkExtractVOI.New();
slicer.SetInput(input);
slicer.SetVOI(extent[0], extent[1], k, k, extent[4], extent[5]);
slicer.Update();
permuter.Dispose();
permuter = vtkImagePermute.New();
permuter.SetInput(slicer.GetOutput());
permuter.SetFilteredAxes(0, 2, 1);
permuter.Update();
}
if (axis == 2)
{
slicer.Dispose();
slicer = vtkExtractVOI.New();
slicer.SetInput(input);
slicer.SetVOI(extent[0], extent[1], extent[2], extent[3], k, k);
slicer.Update();
permuter.Dispose();
permuter = vtkImagePermute.New();
permuter.SetInput(slicer.GetOutput());
permuter.SetFilteredAxes(0, 1, 2);
permuter.Update();
}
//Convert data to byte
bytedata = DataTypes.vtkToByte(permuter.GetOutput());
slicer.Dispose();
permuter.Dispose();
//convert data to Mat
Mat image = new Mat(size[1], size[0], MatType.CV_8UC1, bytedata);
//Get largest binary object
Mat bw = Processing.LargestBWObject(image, 0.7 * 255.0);
//Set slice to byte array
if (bw.Sum().Val0 > 0)
{
output = DataTypes.setByteSlice(output, bw, outextent, axis, k);
}
}
return(DataTypes.byteToVTK(output));
}