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/************************************************************************/
/* */
/* vspline - a set of generic tools for creation and evaluation */
/* of uniform b-splines */
/* */
/* Copyright 2015 - 2023 by Kay F. Jahnke */
/* */
/* Permission is hereby granted, free of charge, to any person */
/* obtaining a copy of this software and associated documentation */
/* files (the "Software"), to deal in the Software without */
/* restriction, including without limitation the rights to use, */
/* copy, modify, merge, publish, distribute, sublicense, and/or */
/* sell copies of the Software, and to permit persons to whom the */
/* Software is furnished to do so, subject to the following */
/* conditions: */
/* */
/* The above copyright notice and this permission notice shall be */
/* included in all copies or substantial portions of the */
/* Software. */
/* */
/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND */
/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES */
/* OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND */
/* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT */
/* HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, */
/* WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING */
/* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR */
/* OTHER DEALINGS IN THE SOFTWARE. */
/* */
/************************************************************************/
/// \file slice3.cc
///
/// \brief create 2D image data from a 3D spline
///
/// build a 3D volume from samples of the RGB colour space
/// build a spline over it and extract a 2D slice
///
/// Here we use a quick shot solution.
/// Oftentimes all it takes is a single run of an interpolation with
/// as little programming effort as possible, never mind the performance.
/// Again we use a b-spline with double-precision voxels as value_type,
/// but instead of using vspline::transform, we simply run the calculations
/// in loops.
///
/// compile with:
/// clang++ -std=c++11 -o slice3 -O3 -pthread slice3.cc -lvigraimpex
/// g++ also works.
#include <iostream>
#include <vspline/vspline.h>
#include <vigra/stdimage.hxx>
#include <vigra/imageinfo.hxx>
#include <vigra/impex.hxx>
// voxel_type is the source data type
typedef vigra::RGBValue < double , 0 , 1 , 2 > voxel_type ;
// pixel_type is the result type, here we use a vigra::RGBValue for a change
typedef vigra::RGBValue < unsigned char , 0 , 1 , 2 > pixel_type ;
// coordinate_type has a 3D coordinate
typedef vigra::TinyVector < float , 3 > coordinate_type ;
int main ( int argc , char * argv[] )
{
// we want a b-spline with natural boundary conditions
vigra::TinyVector < vspline::bc_code , 3 > bcv ( vspline::NATURAL ) ;
// create quintic 3D b-spline object containing voxels
vspline::bspline < voxel_type , 3 >
bspl ( vigra::Shape3 ( 10 , 10 , 10 ) , 5 , bcv ) ;
// fill the b-spline's core with a three-way gradient
for ( int z = 0 ; z < 10 ; z++ )
{
for ( int y = 0 ; y < 10 ; y++ )
{
for ( int x = 0 ; x < 10 ; x++ )
{
bspl.core ( x , y , z ) = voxel_type ( 25.5 * x , 25.5 * y , 25.5 * z ) ;
}
}
}
// prefilter the b-spline
bspl.prefilter() ;
// get an evaluator for the b-spline
auto ev = vspline::make_evaluator ( bspl ) ;
// this is where the result should go:
vigra::MultiArray < 2 , pixel_type > target ( vigra::Shape2 ( 1920 , 1080 ) ) ;
// we want the pick-up coordinates to follow this scheme:
// pick ( x , y ) = ( x , 1 - x , y )
// scaled appropriately
for ( int y = 0 ; y < 1080 ; y++ )
{
for ( int x = 0 ; x < 1920 ; x++ )
{
// calculate the pick-up coordinate
coordinate_type pick { x / 192.0f ,
10.0f - x / 192.0f ,
y / 108.0f } ;
// call the evaluator and store the result to 'target'
target ( x , y ) = ev ( pick ) ;
}
}
// store the result with vigra impex
vigra::ImageExportInfo imageInfo ( "slice.tif" );
vigra::exportImage ( target ,
imageInfo
.setPixelType("UINT8")
.setCompression("100")
.setForcedRangeMapping ( 0 , 255 , 0 , 255 ) ) ;
std::cout << "result was written to slice.tif" << std::endl ;
exit ( 0 ) ;
}
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