Detailed Description

Class Raster is used for managing raster data.

A raster consists of the meta data like number of columns and rows, the lower left point, the size of a raster pixel and a value for invalid data pixels. Additional the object needs the raster data itself. The raster data will be copied from the constructor. The destructor will release the memory.

Definition at line 42 of file Raster.h.

#include <Raster.h>

Collaboration diagram for GeoLib::Raster:

[legend]

Public Types
using	const_iterator = const double *

using	iterator = double *

Public Member Functions
template<typename InputIterator >
	Raster (RasterHeader header, InputIterator begin, InputIterator end)
	Constructor for an object of class Raster. The raster data have to be handed over via input iterators. Deploying iterators has the advantage that the use of the class is independent from the input container. More...

	Raster (Raster const &)=delete

	Raster (Raster &&)=delete

Raster &	operator= (Raster const &)=delete

Raster &	operator= (Raster &&)=delete

RasterHeader const &	getHeader () const
	Returns the complete header information. More...

void	refineRaster (std::size_t scaling)

const_iterator	begin () const

const_iterator	end () const

double	getValueAtPoint (const MathLib::Point3d &pnt) const

double	interpolateValueAtPoint (const MathLib::Point3d &pnt) const
	Interpolates the elevation of the given point based on the 8-neighbourhood of the raster cell it is located on. More...

bool	isPntOnRaster (MathLib::Point3d const &pnt) const
	Checks if the given point is located within the (x,y)-extension of the raster. More...

	~Raster ()

Private Member Functions
void	setCellSize (double cell_size)

void	setNoDataVal (double no_data_val)

Private Attributes
GeoLib::RasterHeader	_header

double *	_raster_data

Member Typedef Documentation

◆ const_iterator

using GeoLib::Raster::const_iterator = const double*

Definition at line 44 of file Raster.h.

◆ iterator

using GeoLib::Raster::iterator = double*

Definition at line 45 of file Raster.h.

Constructor & Destructor Documentation

◆ Raster() [1/3]

template<typename InputIterator >

GeoLib::Raster::Raster	(	RasterHeader	header,
		InputIterator	begin,
		InputIterator	end
	)

inline

Constructor for an object of class Raster. The raster data have to be handed over via input iterators. Deploying iterators has the advantage that the use of the class is independent from the input container.

Parameters

header	meta-information about the raster (height, width, etc.)
begin	input iterator pointing to the first element of the data
end	input iterator pointing to the last element of the data, end have to be reachable from begin

Definition at line 57 of file Raster.h.

         : _header(std::move(header)),
           _raster_data(new double[_header.n_cols * _header.n_rows])
     {
         std::copy(begin, end, _raster_data);
     }

References _raster_data, begin(), MathLib::LinAlg::copy(), and end().

◆ Raster() [2/3]

GeoLib::Raster::Raster ( Raster const & )

delete

◆ Raster() [3/3]

GeoLib::Raster::Raster ( Raster && )

delete

◆ ~Raster()

GeoLib::Raster::~Raster ( )

Definition at line 58 of file Raster.cpp.

 {
     delete[] _raster_data;
 }

References _raster_data.

Member Function Documentation

◆ begin()

const_iterator GeoLib::Raster::begin ( ) const

inline

Constant iterator that is pointing to the first raster pixel value.

Returns: constant iterator

Definition at line 81 of file Raster.h.

81 { return _raster_data; }

References _raster_data.

Referenced by Raster(), LayeredMeshGenerator::calcEpsilon(), MeshLib::RasterToMesh::convert(), and FileIO::AsciiRasterInterface::writeRasterAsASC().

◆ end()

const_iterator GeoLib::Raster::end ( ) const

inline

Constant iterator that is pointing to the last raster pixel value.

Returns: constant iterator

Definition at line 86 of file Raster.h.

86 { return _raster_data + _header.n_rows*_header.n_cols; }

References _header, _raster_data, GeoLib::RasterHeader::n_cols, and GeoLib::RasterHeader::n_rows.

Referenced by Raster(), and LayeredMeshGenerator::calcEpsilon().

◆ getHeader()

RasterHeader const& GeoLib::Raster::getHeader ( ) const

inline

Returns the complete header information.

Definition at line 70 of file Raster.h.

70 { return _header; }

References _header.

Referenced by MeshLib::RasterToMesh::convert(), DirectConditionGenerator::directToSurfaceNodes(), LayeredMeshGenerator::getNewLayerNode(), MeshLib::MeshLayerMapper::layerMapping(), MeshLib::RasterDataToMesh::projectToElements(), MeshLib::RasterDataToMesh::projectToNodes(), and FileIO::AsciiRasterInterface::writeRasterAsASC().

◆ getValueAtPoint()

double GeoLib::Raster::getValueAtPoint ( const MathLib::Point3d & pnt ) const

Returns the raster value at the position of the given point.

Definition at line 63 of file Raster.cpp.

 {
     if (pnt[0] >= _header.origin[0] &&
         pnt[0] < (_header.origin[0] + (_header.cell_size * _header.n_cols)) &&
         pnt[1] >= _header.origin[1] &&
         pnt[1] < (_header.origin[1] + (_header.cell_size * _header.n_rows)))
     {
         auto cell_x = static_cast<int>(
             std::floor((pnt[0] - _header.origin[0]) / _header.cell_size));
         auto cell_y = static_cast<int>(
             std::floor((pnt[1] - _header.origin[1]) / _header.cell_size));
  
         // use raster boundary values if node is outside raster due to rounding
         // errors or floating point arithmetic
         cell_x = (cell_x < 0) ? 0
                               : ((cell_x > static_cast<int>(_header.n_cols))
                                      ? static_cast<int>(_header.n_cols - 1)
                                      : cell_x);
         cell_y = (cell_y < 0) ? 0
                               : ((cell_y > static_cast<int>(_header.n_rows))
                                      ? static_cast<int>(_header.n_rows - 1)
                                      : cell_y);
  
         const std::size_t index = cell_y * _header.n_cols + cell_x;
         return _raster_data[index];
     }
     return _header.no_data;
 }

References _header, _raster_data, GeoLib::RasterHeader::cell_size, GeoLib::RasterHeader::n_cols, GeoLib::RasterHeader::n_rows, GeoLib::RasterHeader::no_data, and GeoLib::RasterHeader::origin.

Referenced by DirectConditionGenerator::directToSurfaceNodes(), and MeshLib::MeshLayerMapper::layerMapping().

◆ interpolateValueAtPoint()

double GeoLib::Raster::interpolateValueAtPoint ( const MathLib::Point3d & pnt ) const

Interpolates the elevation of the given point based on the 8-neighbourhood of the raster cell it is located on.

Definition at line 92 of file Raster.cpp.

 {
     // position in raster
     double const xPos((pnt[0] - _header.origin[0]) / _header.cell_size);
     double const yPos((pnt[1] - _header.origin[1]) / _header.cell_size);
     // raster cell index
     double const xIdx(std::floor(xPos));  // carry out computions in double
     double const yIdx(std::floor(yPos));  //  so not to over- or underflow.
  
     // weights for bilinear interpolation
     double const xShift = std::abs((xPos - xIdx) - 0.5);
     double const yShift = std::abs((yPos - yIdx) - 0.5);
     Eigen::Vector4d weight = {(1 - xShift) * (1 - yShift),
                               xShift * (1 - yShift), xShift * yShift,
                               (1 - xShift) * yShift};
  
     // neighbors to include in interpolation
     int const xShiftIdx = (xPos - xIdx >= 0.5) ? 1 : -1;
     int const yShiftIdx = (yPos - yIdx >= 0.5) ? 1 : -1;
     std::array<int, 4> const x_nb = {{0, xShiftIdx, xShiftIdx, 0}};
     std::array<int, 4> const y_nb = {{0, 0, yShiftIdx, yShiftIdx}};
  
     // get pixel values
     Eigen::Vector4d pix_val{};
     unsigned no_data_count(0);
     for (unsigned j = 0; j < 4; ++j)
     {
         // check if neighbour pixel is still on the raster, otherwise substitute
         // a no data value. This also allows the cast to unsigned type.
         if ((xIdx + x_nb[j]) < 0 || (yIdx + y_nb[j]) < 0 ||
             (xIdx + x_nb[j]) > (_header.n_cols - 1) ||
             (yIdx + y_nb[j]) > (_header.n_rows - 1))
         {
             pix_val[j] = _header.no_data;
         }
         else
         {
             pix_val[j] = _raster_data[static_cast<std::size_t>(yIdx + y_nb[j]) *
                                           _header.n_cols +
                                       static_cast<std::size_t>(xIdx + x_nb[j])];
         }
  
         // remove no data values
         if (std::abs(pix_val[j] - _header.no_data) <
             std::numeric_limits<double>::epsilon())
         {
             weight[j] = 0;
             no_data_count++;
         }
     }
  
     // adjust weights if necessary
     if (no_data_count > 0)
     {
         if (no_data_count == 4)
         {  // if there is absolutely no data just use the default value
             return _header.no_data;
         }
  
         weight /= weight.sum();
     }
  
     // new value
     return weight.dot(pix_val);
 }

References _header, _raster_data, GeoLib::RasterHeader::cell_size, GeoLib::RasterHeader::n_cols, GeoLib::RasterHeader::n_rows, GeoLib::RasterHeader::no_data, and GeoLib::RasterHeader::origin.

Referenced by VtkImageDataToSurfacePointsFilter::createPointSurface(), LayeredMeshGenerator::getNewLayerNode(), and MeshLib::MeshLayerMapper::layerMapping().

◆ isPntOnRaster()

bool GeoLib::Raster::isPntOnRaster ( MathLib::Point3d const & pnt ) const

Checks if the given point is located within the (x,y)-extension of the raster.

Definition at line 158 of file Raster.cpp.

 {
     return !(
         (pnt[0] < _header.origin[0]) ||
         (pnt[0] > _header.origin[0] + (_header.n_cols * _header.cell_size)) ||
         (pnt[1] < _header.origin[1]) ||
         (pnt[1] > _header.origin[1] + (_header.n_rows * _header.cell_size)));
 }

References _header, GeoLib::RasterHeader::cell_size, GeoLib::RasterHeader::n_cols, GeoLib::RasterHeader::n_rows, and GeoLib::RasterHeader::origin.

Referenced by MeshLib::MeshLayerMapper::layerMapping().

◆ operator=() [1/2]

Raster& GeoLib::Raster::operator= ( Raster && )

delete

◆ operator=() [2/2]

Raster& GeoLib::Raster::operator= ( Raster const & )

delete

◆ refineRaster()

void GeoLib::Raster::refineRaster ( std::size_t scaling )

Refine the raster using scaling as a refinement parameter.

Definition at line 25 of file Raster.cpp.

 {
     auto* new_raster_data(
         new double[_header.n_rows * _header.n_cols * scaling * scaling]);
  
     for (std::size_t row(0); row < _header.n_rows; row++)
     {
         for (std::size_t col(0); col < _header.n_cols; col++)
         {
             const std::size_t idx(row * _header.n_cols + col);
             for (std::size_t new_row(row * scaling);
                  new_row < (row + 1) * scaling;
                  new_row++)
             {
                 const std::size_t idx0(new_row * _header.n_cols * scaling);
                 for (std::size_t new_col(col * scaling);
                      new_col < (col + 1) * scaling;
                      new_col++)
                 {
                     new_raster_data[idx0 + new_col] = _raster_data[idx];
                 }
             }
         }
     }
  
     std::swap(_raster_data, new_raster_data);
     _header.cell_size /= scaling;
     _header.n_cols *= scaling;
     _header.n_rows *= scaling;
  
     delete[] new_raster_data;
 }

References _header, _raster_data, GeoLib::RasterHeader::cell_size, GeoLib::RasterHeader::n_cols, and GeoLib::RasterHeader::n_rows.

◆ setCellSize()

void GeoLib::Raster::setCellSize ( double cell_size )

private

◆ setNoDataVal()

void GeoLib::Raster::setNoDataVal ( double no_data_val )

private

Member Data Documentation

◆ _header

GeoLib::RasterHeader GeoLib::Raster::_header

private

Definition at line 105 of file Raster.h.

Referenced by end(), getHeader(), getValueAtPoint(), interpolateValueAtPoint(), isPntOnRaster(), and refineRaster().

◆ _raster_data

double* GeoLib::Raster::_raster_data

private

Definition at line 106 of file Raster.h.

Referenced by Raster(), ~Raster(), begin(), end(), getValueAtPoint(), interpolateValueAtPoint(), and refineRaster().

The documentation for this class was generated from the following files:

GeoLib/Raster.h
GeoLib/Raster.cpp

Detailed Description

Public Types

Public Member Functions

Private Member Functions

Private Attributes

Member Typedef Documentation

◆ const_iterator

◆ iterator

Constructor & Destructor Documentation

◆ Raster() [1/3]

◆ Raster() [2/3]

◆ Raster() [3/3]

◆ ~Raster()

Member Function Documentation

◆ begin()

◆ end()

◆ getHeader()

◆ getValueAtPoint()

◆ interpolateValueAtPoint()

◆ isPntOnRaster()

◆ operator=() [1/2]

◆ operator=() [2/2]

◆ refineRaster()

◆ setCellSize()

◆ setNoDataVal()

Member Data Documentation

◆ _header

◆ _raster_data