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details Geometric Transformations VIGRA

Functions

template<... >
void affineWarpImage (...)
 Warp an image according to an affine transformation.
template<... >
void reflectImage (...)
 Reflect image horizontally or vertically.
template<... >
void resampleImage (...)
 Resample image by a given factor.
template<... >
void resizeImageCatmullRomInterpolation (...)
 Resize image using the Catmull/Rom interpolation function.
template<... >
void resizeImageCoscotInterpolation (...)
 Resize image using the Coscot interpolation function.
template<... >
void resizeImageLinearInterpolation (...)
 Resize image using linear interpolation.
template<... >
void resizeImageNoInterpolation (...)
 Resize image by repeating the nearest pixel values.
template<... >
void resizeImageSplineInterpolation (...)
 Resize image using B-spline interpolation.
template<... >
void resizeMultiArraySplineInterpolation (...)
 Resize MultiArray using B-spline interpolation.
template<... >
void rotateImage (...)
 Rotate image by an arbitrary angle.
linalg::TemporaryMatrix< double > rotationMatrix2DDegrees (double angle)
 Create homogeneous matrix representing a 2D rotation about the coordinate origin.
linalg::TemporaryMatrix< double > rotationMatrix2DDegrees (double angle, TinyVector< double, 2 > const &center)
 Create homogeneous matrix representing a 2D rotation about the given point.
linalg::TemporaryMatrix< double > rotationMatrix2DRadians (double angle)
 Create homogeneous matrix representing a 2D rotation about the coordinate origin.
linalg::TemporaryMatrix< double > rotationMatrix2DRadians (double angle, TinyVector< double, 2 > const &center)
 Create homogeneous matrix representing a 2D rotation about the given point.
linalg::TemporaryMatrix< double > scalingMatrix2D (double scalingFactor)
 Create homogeneous matrix representing a 2D uniform scaling about the coordinate origin.
linalg::TemporaryMatrix< double > scalingMatrix2D (double sx, double sy)
 Create homogeneous matrix representing a 2D non-uniform scaling about the coordinate origin.
linalg::TemporaryMatrix< double > shearMatrix2D (double s01, double s10)
 Create homogeneous matrix representing a 2D shearing.
linalg::TemporaryMatrix< double > translationMatrix2D (TinyVector< double, 2 > const &shift)
 Create homogeneous matrix representing a 2D translation.
template<... >
void transposeImage (...)
 Transpose an image over the major or minor diagonal.


Detailed Description

Zoom up and down by repeating pixels, or using various interpolation schemes.

See also: resamplingConvolveImage(), resampleImage(), resizeMultiArraySplineInterpolation()

#include <vigra/stdimagefunctions.hxx>
or
#include <vigra/resizeimage.hxx>


Function Documentation

linalg::TemporaryMatrix<double> vigra::translationMatrix2D ( TinyVector< double, 2 > const &  shift)

Create homogeneous matrix representing a 2D translation.

For use with affineWarpImage().

linalg::TemporaryMatrix<double> vigra::scalingMatrix2D ( double  scalingFactor)

Create homogeneous matrix representing a 2D uniform scaling about the coordinate origin.

For use with affineWarpImage().

linalg::TemporaryMatrix<double> vigra::scalingMatrix2D ( double  sx,
double  sy 
)

Create homogeneous matrix representing a 2D non-uniform scaling about the coordinate origin.

For use with affineWarpImage().

linalg::TemporaryMatrix<double> vigra::shearMatrix2D ( double  s01,
double  s10 
)

Create homogeneous matrix representing a 2D shearing.

For use with affineWarpImage().

linalg::TemporaryMatrix<double> vigra::rotationMatrix2DRadians ( double  angle)

Create homogeneous matrix representing a 2D rotation about the coordinate origin.

For use with affineWarpImage(). Angle must be in radians.

linalg::TemporaryMatrix<double> vigra::rotationMatrix2DDegrees ( double  angle)

Create homogeneous matrix representing a 2D rotation about the coordinate origin.

For use with affineWarpImage(). Angle must be in degrees.

linalg::TemporaryMatrix<double> vigra::rotationMatrix2DRadians ( double  angle,
TinyVector< double, 2 > const &  center 
)

Create homogeneous matrix representing a 2D rotation about the given point.

For use with affineWarpImage(). Angle must be in radians.

linalg::TemporaryMatrix<double> vigra::rotationMatrix2DDegrees ( double  angle,
TinyVector< double, 2 > const &  center 
)

Create homogeneous matrix representing a 2D rotation about the given point.

For use with affineWarpImage(). Angle must be in degrees.

void rotateImage (   ...)

Rotate image by an arbitrary angle.

Rotate image by a multiple of 90 degrees.

The algorithm performs a rotation about the given center point (the image center by default) using the given SplineImageView for interpolation. The destination image must have the same size as the source SplineImageView. The rotation is counter-clockwise, and the angle must be given in degrees.

Declarations:

pass arguments explicitly:

    namespace vigra {
        // rotate about given center point
        template <int ORDER, class T, 
                  class DestIterator, class DestAccessor>
        void rotateImage(SplineImageView<ORDER, T> const & src,
                         DestIterator id, DestAccessor dest, 
                         double angleInDegree, TinyVector<double, 2> const & center);
                         
        // rotate about image center
        template <int ORDER, class T, 
                  class DestIterator, class DestAccessor>
        void 
        rotateImage(SplineImageView<ORDER, T> const & src,
                    DestIterator id, DestAccessor dest, 
                    double angleInDegree)
    }

use argument objects in conjunction with Argument Object Factories :

    namespace vigra {
        // rotate about given center point
        template <int ORDER, class T, 
                  class DestIterator, class DestAccessor>
        void 
        rotateImage(SplineImageView<ORDER, T> const & src,
                    pair<DestImageIterator, DestAccessor> dest, 
                    double angleInDegree, TinyVector<double, 2> const & center);

        // rotate about image center
        template <int ORDER, class T, 
                  class DestIterator, class DestAccessor>
        void 
        rotateImage(SplineImageView<ORDER, T> const & src,
                    pair<DestImageIterator, DestAccessor> dest, 
                    double angleInDegree);
    }

Usage:

#include <vigra/affinegeometry.hxx>
Namespace: vigra

    Image src(width, height);
    vigra::SplineImageView<3, Image::value_type> spline(srcImageRange(src));
    
    Image dest(width, height);
    
    vigra::rotateImage(spline, destImage(dest), 38.5);

Required Interface:

    DestImageIterator dest_upperleft;
    
    double x = ..., y = ...;
    
    if (spline.isInside(x,y))
        dest_accessor.set(spline(x, y), dest_upperleft);

This algorithm just copies the pixels in the appropriate new order. It expects the destination image to have the correct shape for the desired rotation.

Declarations:

pass arguments explicitly:

    namespace vigra {
        template <class SrcIterator, class SrcAccessor,
                  class DestIterator, class DestAccessor>
        void 
        rotateImage(SrcIterator is, SrcIterator end, SrcAccessor as,
                    DestIterator id, DestAccessor ad, int rotation);
    }

use argument objects in conjunction with Argument Object Factories :

    namespace vigra {
        template <class SrcImageIterator, class SrcAccessor,
              class DestImageIterator, class DestAccessor>
        inline void 
        rotateImage(triple<SrcImageIterator, SrcImageIterator, SrcAccessor> src,
                    pair<DestImageIterator, DestAccessor> dest, int rotation);
    }

Usage:

#include <vigra/basicgeometry.hxx>
Namespace: vigra

    Image dest(src.height(), src.width()); // note that width and height are exchanged
    
    vigra::rotateImage(srcImageRange(src), destImage(dest), 90);

Required Interface:

    SrcImageIterator src_upperleft, src_lowerright;
    DestImageIterator dest_upperleft;
    
    SrcAccessor src_accessor;
    
    dest_accessor.set(src_accessor(src_upperleft), dest_upperleft);

Preconditions:

    src_lowerright.x - src_upperleft.x > 1
    src_lowerright.y - src_upperleft.y > 1
void vigra::affineWarpImage (   ...)

Warp an image according to an affine transformation.

Declarations:

pass arguments explicitly:

    namespace vigra {
        template <int ORDER, class T, 
                class DestIterator, class DestAccessor,
                class C>
        void affineWarpImage(SplineImageView<ORDER, T> const & src,
                            DestIterator dul, DestIterator dlr, DestAccessor dest, 
                            MultiArrayView<2, double, C> const & affineMatrix);
    }

use argument objects in conjunction with Argument Object Factories :

    namespace vigra {
        template <int ORDER, class T, 
                class DestIterator, class DestAccessor,
                class C>
        void affineWarpImage(SplineImageView<ORDER, T> const & src,
                            triple<DestIterator, DestIterator, DestAccessor> dest, 
                            MultiArrayView<2, double, C> const & affineMatrix);
    }

The algorithm applies the given affineMatrix to the destination coordinates and copies the image value from the resulting source coordinates, using the given SplineImageView src for interpolation. If the resulting coordinate is outside the source image, nothing will be written at that destination point.

        for all dest pixels:
            currentSrcCoordinate = affineMatrix * currentDestCoordinate;
            if src.isInside(currentSrcCoordinate):
                dest[currentDestCoordinate] = src[currentSrcCoordinate]; // copy an interpolated value

The matrix represent a 2-dimensional affine transform by means of homogeneous coordinates, i.e. it must be a 3x3 matrix whose last row is (0,0,1).

Usage:

#include <vigra/affinegeometry.hxx>
Namespace: vigra

    Image src(width, height);
    vigra::SplineImageView<3, Image::value_type> spline(srcImageRange(src));
    
    Image dest1(width, height);
    
    // equivalent (up to round-off errors) with 
    //     rotateImage(spline, destImage(dest1), 45.0);
    TinyVector<double, 2> center((width-1.0)/2.0, (height-1.0)/2.0);
    affineWarpImage(spline, destImageRange(dest1), rotationMatrix2DDegrees(45.0, center));
    
    Image dest2(2*width-1, 2*height-1);
    
    // equivalent (up to round-off errors) with 
    //     resizeImageSplineInterpolation(srcImageRange(img), destImageRange(dest2));
    // note that scaleFactor = 0.5, because we must pass the transformation from destination to source
    affineWarpImage(spline, destImageRange(dest2), scalingMatrix2D(0.5));

Required Interface:

    DestImageIterator dest_upperleft;
    
    double x = ..., y = ...;
    
    if (spline.isInside(x,y))
        dest_accessor.set(spline(x, y), dest_upperleft);

See also: Functions to specify affine transformation: translationMatrix2D(), scalingMatrix2D(), shearMatrix2D(), rotationMatrix2DRadians(), rotationMatrix2DDegrees()

void vigra::reflectImage (   ...)

Reflect image horizontally or vertically.

The reflection direction refers to the reflection axis, i.e. horizontal reflection turns the image upside down, vertical reflection changes left for right. The directions are selected by the enum values vigra::horizontal and vigra::vertical. The two directions can also be "or"ed together to perform both reflections simultaneously (see example below) -- this is the same as a 180 degree rotation.

Declarations:

pass arguments explicitly:

    namespace vigra {
        template <class SrcIterator, class SrcAccessor,
                  class DestIterator, class DestAccessor>
        void 
        reflectImage(SrcIterator is, SrcIterator end, SrcAccessor as,
                     DestIterator id, DestAccessor ad, Reflect axis);
    }

use argument objects in conjunction with Argument Object Factories :

    namespace vigra {
        template <class SrcImageIterator, class SrcAccessor,
              class DestImageIterator, class DestAccessor>
        inline void 
        reflectImage(triple<SrcImageIterator, SrcImageIterator, SrcAccessor> src,
                     pair<DestImageIterator, DestAccessor> dest, Reflect axis);
    }

Usage:

#include <vigra/basicgeometry.hxx>
Namespace: vigra

    Image dest(src.width(), src.height());
    
    vigra::reflectImage(srcImageRange(src), destImage(dest), vigra::horizontal | vigra::vertical);

Required Interface:

    SrcImageIterator src_upperleft, src_lowerright;
    DestImageIterator dest_upperleft;
    
    SrcAccessor src_accessor;
    
    dest_accessor.set(src_accessor(src_upperleft), dest_upperleft);

Preconditions:

    src_lowerright.x - src_upperleft.x > 1
    src_lowerright.y - src_upperleft.y > 1
void vigra::transposeImage (   ...)

Transpose an image over the major or minor diagonal.

The transposition direction refers to the axis, i.e. major transposition turns the upper right corner into the lower left one, whereas minor transposition changes the upper left corner into the lower right one. The directions are selected by the enum values vigra::major and vigra::minor. The two directions can also be "or"ed together to perform both reflections simultaneously (see example below) -- this is the same as a 180 degree rotation. (Caution: When doing multi-platform development, you should be aware that some <sys/types.h> define major/minor, too. Do not omit the vigra namespace prefix.)

Declarations:

pass arguments explicitly:

    namespace vigra {
        template <class SrcIterator, class SrcAccessor,
                  class DestIterator, class DestAccessor>
        void 
        transposeImage(SrcIterator is, SrcIterator end, SrcAccessor as,
                       DestIterator id, DestAccessor ad, Transpose axis);
    }

use argument objects in conjunction with Argument Object Factories :

    namespace vigra {
        template <class SrcImageIterator, class SrcAccessor,
              class DestImageIterator, class DestAccessor>
        inline void 
        transposeImage(triple<SrcImageIterator, SrcImageIterator, SrcAccessor> src,
                       pair<DestImageIterator, DestAccessor> dest, Transpose axis);
    }

Usage:

#include <vigra/basicgeometry.hxx>
Namespace: vigra

    Image dest(src.width(), src.height());
    
    vigra::transposeImage(srcImageRange(src), destImage(dest), vigra::major | vigra::minor);

Required Interface:

    SrcImageIterator src_upperleft, src_lowerright;
    DestImageIterator dest_upperleft;
    
    SrcAccessor src_accessor;
    
    dest_accessor.set(src_accessor(src_upperleft), dest_upperleft);

Preconditions:

    src_lowerright.x - src_upperleft.x > 1
    src_lowerright.y - src_upperleft.y > 1
void vigra::resampleImage (   ...)

Resample image by a given factor.

This algorithm is very fast and does not require any arithmetic on the pixel types. The input image must have a size of at least 2x2. Destiniation pixels are directly copied from the appropriate source pixels. The size of the result image is the product of factor and the original size, where we round up if factor < 1.0 and down otherwise. This size calculation is the main difference to the convention used in the similar function resizeImageNoInterpolation(): there, the result size is calculated as n*(old_width-1)+1 and n*(old_height-1)+1. This is because resizeImageNoInterpolation() does not replicate the last pixel in every row/column in order to make it compatible with the other functions of the resizeImage... family.

The function can be called with different resampling factors for x and y, or with a single factor to be used for both directions.

It should also be noted that resampleImage() is implemented so that an enlargement followed by the corresponding shrinking reproduces the original image. The function uses accessors.

Declarations:

pass arguments explicitly:

    namespace vigra {
        template <class SrcIterator, class SrcAccessor,
                  class DestIterator, class DestAccessor>
        void 
        resampleImage(SrcIterator is, SrcIterator iend, SrcAccessor sa,
                      DestIterator id, DestAccessor ad, double factor);
                      
        template <class SrcIterator, class SrcAccessor,
                  class DestIterator, class DestAccessor>
        void 
        resampleImage(SrcIterator is, SrcIterator iend, SrcAccessor sa,
                      DestIterator id, DestAccessor ad, double xfactor, double yfactor);
    }

use argument objects in conjunction with Argument Object Factories :

    namespace vigra {
        template <class SrcImageIterator, class SrcAccessor,
              class DestImageIterator, class DestAccessor>
        inline void 
        resampleImage(triple<SrcImageIterator, SrcImageIterator, SrcAccessor> src,
                      pair<DestImageIterator, DestAccessor> dest, double factor);
                      
        template <class SrcImageIterator, class SrcAccessor,
              class DestImageIterator, class DestAccessor>
        inline void 
        resampleImage(triple<SrcImageIterator, SrcImageIterator, SrcAccessor> src,
                      pair<DestImageIterator, DestAccessor> dest, double xfactor, double yfactor);
    }

Usage:

#include <vigra/basicgeometry.hxx>
Namespace: vigra

    double factor = 2.0;
    Image dest((int)(factor*src.width()), (int)(factor*src.height()));
    
    vigra::resampleImage(srcImageRange(src), destImage(dest), factor);

Required Interface:

    SrcImageIterator src_upperleft, src_lowerright;
    DestImageIterator dest_upperleft;
    
    SrcAccessor src_accessor;
    
    dest_accessor.set(src_accessor(src_upperleft), dest_upperleft);

Preconditions:

    src_lowerright.x - src_upperleft.x > 1
    src_lowerright.y - src_upperleft.y > 1

Resize MultiArray using B-spline interpolation.

Declarations:

pass arguments explicitly:

    namespace vigra {
        template <class SrcIterator, class Shape, class SrcAccessor,
                  class DestIterator, class DestAccessor,
                  class Kernel = BSpline<3, double> >
        void
        resizeMultiArraySplineInterpolation(
                              SrcIterator si, Shape const & sshape, SrcAccessor src,
                              DestIterator di, Shape const & dshape, DestAccessor dest,
                              Kernel const & spline = BSpline<3, double>());
    }

use argument objects in conjunction with Argument Object Factories :

    namespace vigra {
        template <class SrcIterator, class Shape, class SrcAccessor,
                  class DestIterator, class DestAccessor,
                  class Kernel = BSpline<3, double> >
        void
        resizeMultiArraySplineInterpolation(
                              triple<SrcIterator, Shape, SrcAccessor> src,
                              triple<DestIterator, Shape, DestAccessor> dest,
                              Kernel const & spline = BSpline<3, double>());
    }

The function implements separable spline interpolation algorithm described in

M. Unser, A. Aldroubi, M. Eden, "B-Spline Signal Processing" IEEE Transactions on Signal Processing, vol. 41, no. 2, pp. 821-833 (part I), pp. 834-848 (part II), 1993.

to obtain optimal interpolation quality and speed. You may pass the function a spline of arbitrary order (e.g. BSpline<ORDER, double> or CatmullRomSpline<double>). The default is a third order spline which gives a twice continuously differentiable interpolant. The implementation ensures that image values are interpolated rather than smoothed by first calling a recursive (sharpening) prefilter as described in the above paper. Then the actual interpolation is done using resamplingConvolveLine().

The range of both the input and output images (resp. regions) must be given. The input image must have a size of at least 4x4, the destination of at least 2x2. The scaling factors are then calculated accordingly. If the source image is larger than the destination, it is smoothed (band limited) using a recursive exponential filter. The source value_type (SrcAccessor::value_type) must be a linear algebra, i.e. it must support addition, subtraction, and multiplication (+, -, *), multiplication with a scalar real number and NumericTraits. The function uses accessors.

Usage:

#include <vigra/multi_resize.hxx>
Namespace: vigra

    typedef vigra::MultiArray<3, float>::difference_type Shape;
    vigra::MultiArray<3, float> src(Shape(5, 7, 10)),
                                dest(Shape(9, 13, 19)); // double the size

    // use default cubic spline interpolator
    vigra::resizeMultiArraySplineInterpolation(
               srcMultiArrayRange(src),
               destMultiArrayRange(dest));

Required Interface:

The source and destination iterators must be compatible with vigra::MultiIterator. The array value types must be models of LinearSpace.

Resize image by repeating the nearest pixel values.

This algorithm is very fast and does not require any arithmetic on the pixel types.

The range of both the input and output images (resp. regions) must be given. Both images must have a size of at least 2x2 pixels. The scaling factors are then calculated accordingly. Destination pixels are directly copied from the appropriate source pixels.

The function uses accessors.

Declarations:

pass arguments explicitly:

    namespace vigra {
        template <class SrcImageIterator, class SrcAccessor,
                  class DestImageIterator, class DestAccessor>
        void
        resizeImageNoInterpolation(
              SrcImageIterator is, SrcImageIterator iend, SrcAccessor sa,
              DestImageIterator id, DestImageIterator idend, DestAccessor da)
    }

use argument objects in conjunction with Argument Object Factories :

    namespace vigra {
        template <class SrcImageIterator, class SrcAccessor,
                  class DestImageIterator, class DestAccessor>
        void
        resizeImageNoInterpolation(
              triple<SrcImageIterator, SrcImageIterator, SrcAccessor> src,
              triple<DestImageIterator, DestImageIterator, DestAccessor> dest)
    }

Usage:

#include <vigra/resizeimage.hxx>
Namespace: vigra

    vigra::resizeImageNoInterpolation(
               src.upperLeft(), src.lowerRight(), src.accessor(),
               dest.upperLeft(), dest.lowerRight(), dest.accessor());

Required Interface:

    SrcImageIterator src_upperleft, src_lowerright;
    DestImageIterator dest_upperleft, src_lowerright;

    SrcAccessor src_accessor;
    DestAccessor dest_accessor;

    dest_accessor.set(src_accessor(src_upperleft), dest_upperleft);

Preconditions:

    src_lowerright.x - src_upperleft.x > 1
    src_lowerright.y - src_upperleft.y > 1
    dest_lowerright.x - dest_upperleft.x > 1
    dest_lowerright.y - dest_upperleft.y > 1
Examples:
pyramid.cxx, and resize.cxx.

Resize image using linear interpolation.

The function uses the standard separable bilinear interpolation algorithm to obtain a good compromise between quality and speed.

The range must of both the input and output images (resp. regions) must be given. Both images must have a size of at least 2x2. The scaling factors are then calculated accordingly. If the source image is larger than the destination, it is smoothed (band limited) using a recursive exponential filter. The source value_type (SrcAccessor::value_type) must be a linear space, i.e. it must support addition, multiplication with a scalar real number and NumericTraits. The function uses accessors.

Declarations:

pass arguments explicitly:

    namespace vigra {
        template <class SrcImageIterator, class SrcAccessor,
                  class DestImageIterator, class DestAccessor>
        void
        resizeImageLinearInterpolation(
              SrcImageIterator is, SrcImageIterator iend, SrcAccessor sa,
              DestImageIterator id, DestImageIterator idend, DestAccessor da)
    }

use argument objects in conjunction with Argument Object Factories :

    namespace vigra {
        template <class SrcImageIterator, class SrcAccessor,
                  class DestImageIterator, class DestAccessor>
        void
        resizeImageLinearInterpolation(
              triple<SrcImageIterator, SrcImageIterator, SrcAccessor> src,
              triple<DestImageIterator, DestImageIterator, DestAccessor> dest)
    }

Usage:

#include <vigra/resizeimage.hxx>
Namespace: vigra

    vigra::resizeImageLinearInterpolation(
               src.upperLeft(), src.lowerRight(), src.accessor(),
               dest.upperLeft(), dest.lowerRight(), dest.accessor());

Required Interface:

    SrcImageIterator src_upperleft, src_lowerright;
    DestImageIterator dest_upperleft, src_lowerright;

    SrcAccessor src_accessor;
    DestAccessor dest_accessor;

    NumericTraits<SrcAccessor::value_type>::RealPromote
                             u = src_accessor(src_upperleft),
                 v = src_accessor(src_upperleft, 1);
    double d;

    u = d * v;
    u = u + v;

    dest_accessor.set(
        NumericTraits<DestAccessor::value_type>::fromRealPromote(u),
    dest_upperleft);

Preconditions:

    src_lowerright.x - src_upperleft.x > 1
    src_lowerright.y - src_upperleft.y > 1
    dest_lowerright.x - dest_upperleft.x > 1
    dest_lowerright.y - dest_upperleft.y > 1
Examples:
resize.cxx.

Resize image using B-spline interpolation.

The function implements separable spline interpolation algorithm described in

M. Unser, A. Aldroubi, M. Eden, "B-Spline Signal Processing" IEEE Transactions on Signal Processing, vol. 41, no. 2, pp. 821-833 (part I), pp. 834-848 (part II), 1993.

to obtain optimal interpolation quality and speed. You may pass the function a spline of arbitrary order (e.g. BSpline<ORDER, double> or CatmullRomSpline<double>). The default is a third order spline which gives a twice continuously differentiable interpolant. The implementation ensures that image values are interpolated rather than smoothed by first calling a recursive (sharpening) prefilter as described in the above paper. Then the actual interpolation is done using resamplingConvolveLine().

The range of both the input and output images (resp. regions) must be given. The input image must have a size of at least 4x4, the destination of at least 2x2. The scaling factors are then calculated accordingly. If the source image is larger than the destination, it is smoothed (band limited) using a recursive exponential filter. The source value_type (SrcAccessor::value_type) must be a linear algebra, i.e. it must support addition, subtraction, and multiplication (+, -, *), multiplication with a scalar real number and NumericTraits. The function uses accessors.

Declarations:

pass arguments explicitly:

    namespace vigra {
        template <class SrcImageIterator, class SrcAccessor,
                  class DestImageIterator, class DestAccessor,
                  class SPLINE>
        void
        resizeImageSplineInterpolation(
              SrcImageIterator is, SrcImageIterator iend, SrcAccessor sa,
              DestImageIterator id, DestImageIterator idend, DestAccessor da,
              SPLINE spline = BSpline<3, double>())
    }

use argument objects in conjunction with Argument Object Factories :

    namespace vigra {
        template <class SrcImageIterator, class SrcAccessor,
                  class DestImageIterator, class DestAccessor,
                  class SPLINE>
        void
        resizeImageSplineInterpolation(
              triple<SrcImageIterator, SrcImageIterator, SrcAccessor> src,
              triple<DestImageIterator, DestImageIterator, DestAccessor> dest,
              SPLINE spline = BSpline<3, double>())
    }

Usage:

#include <vigra/resizeimage.hxx>
Namespace: vigra

    vigra::resizeImageSplineInterpolation(
               src.upperLeft(), src.lowerRight(), src.accessor(),
               dest.upperLeft(), dest.lowerRight(), dest.accessor());

Required Interface:

    SrcImageIterator src_upperleft, src_lowerright;
    DestImageIterator dest_upperleft, src_lowerright;

    SrcAccessor src_accessor;
    DestAccessor dest_accessor;

    NumericTraits<SrcAccessor::value_type>::RealPromote
                             u = src_accessor(src_upperleft),
                 v = src_accessor(src_upperleft, 1);
    double d;

    u = d * v;
    u = u + v;
    u = u - v;
    u = u * v;
    u += v;
    u -= v;

    dest_accessor.set(
        NumericTraits<DestAccessor::value_type>::fromRealPromote(u),
    dest_upperleft);

Preconditions:

    src_lowerright.x - src_upperleft.x > 3
    src_lowerright.y - src_upperleft.y > 3
    dest_lowerright.x - dest_upperleft.x > 1
    dest_lowerright.y - dest_upperleft.y > 1
Examples:
resize.cxx.

Resize image using the Catmull/Rom interpolation function.

The function calls like resizeImageSplineInterpolation() with vigra::CatmullRomSpline as an interpolation kernel. The interpolated function has one continuous derivative. (See resizeImageSplineInterpolation() for more documentation)

Declarations:

pass arguments explicitly:

    namespace vigra {
        template <class SrcIterator, class SrcAccessor,
                  class DestIterator, class DestAccessor>
        void
        resizeImageCatmullRomInterpolation(SrcIterator src_iter, SrcIterator src_iter_end, SrcAccessor src_acc,
                              DestIterator dest_iter, DestIterator dest_iter_end, DestAccessor dest_acc);
    }

use argument objects in conjunction with Argument Object Factories :

    namespace vigra {
        template <class SrcIterator, class SrcAccessor,
                  class DestIterator, class DestAccessor>
        void
        resizeImageCatmullRomInterpolation(triple<SrcIterator, SrcIterator, SrcAccessor> src,
                              triple<DestIterator, DestIterator, DestAccessor> dest);
    }

#include <vigra/resizeimage.hxx>
Namespace: vigra

Resize image using the Coscot interpolation function.

The function calls resizeImageSplineInterpolation() with vigra::CoscotFunction as an interpolation kernel. The interpolated function has one continuous derivative. (See resizeImageSplineInterpolation() for more documentation)

Declarations:

pass arguments explicitly:

    namespace vigra {
        template <class SrcIterator, class SrcAccessor,
                  class DestIterator, class DestAccessor>
        void
        resizeImageCoscotInterpolation(SrcIterator src_iter, SrcIterator src_iter_end, SrcAccessor src_acc,
                              DestIterator dest_iter, DestIterator dest_iter_end, DestAccessor dest_acc);
    }

use argument objects in conjunction with Argument Object Factories :

    namespace vigra {
        template <class SrcIterator, class SrcAccessor,
                  class DestIterator, class DestAccessor>
        void
        resizeImageCoscotInterpolation(triple<SrcIterator, SrcIterator, SrcAccessor> src,
                              triple<DestIterator, DestIterator, DestAccessor> dest);
    }

#include <vigra/resizeimage.hxx>
Namespace: vigra

© Ullrich Köthe (ullrich.koethe@iwr.uni-heidelberg.de)
Heidelberg Collaboratory for Image Processing, University of Heidelberg, Germany

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vigra 1.9.0 (Tue Nov 6 2012)