Revision 3aa616282b380f949257a2f086017170e352aa99 authored by renchao_lu on 24 June 2021, 18:50:34 UTC, committed by renchao_lu on 27 June 2021, 11:18:32 UTC
1 parent 9baf475
Raster.cpp
/**
* @file Raster.cpp
* @author Thomas Fischer
* @date 2011-09-07
* @brief Implementation of the GeoLib::Raster class.
*
* @copyright
* Copyright (c) 2012-2021, OpenGeoSys Community (http://www.opengeosys.org)
* Distributed under a Modified BSD License.
* See accompanying file LICENSE.txt or
* http://www.opengeosys.org/project/license
*/
#include "Raster.h"
#include <fstream>
// BaseLib
#include "BaseLib/FileTools.h"
#include "BaseLib/StringTools.h"
#include "Triangle.h"
namespace GeoLib
{
void Raster::refineRaster(std::size_t scaling)
{
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;
}
Raster::~Raster()
{
delete[] _raster_data;
}
double Raster::getValueAtPoint(const MathLib::Point3d& pnt) const
{
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;
}
double Raster::interpolateValueAtPoint(MathLib::Point3d const& pnt) const
{
// 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);
}
bool Raster::isPntOnRaster(MathLib::Point3d const& pnt) const
{
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)));
}
} // end namespace GeoLib
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