scalefilter.cpp File Reference

#include "qimageblitz.h"
#include <cmath>

Include dependency graph for scalefilter.cpp:

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Namespaces
namespace	BlitzScaleFilter
Defines
#define	B   (1.0/3.0)
#define	C   (1.0/3.0)
#define	MagickEpsilon   1.0e-6
#define	MagickPI   3.14159265358979323846264338327950288419716939937510
#define	P0   (( 6.0- 2.0*B )/6.0)
#define	P2   ((-18.0+12.0*B+ 6.0*C)/6.0)
#define	P3   (( 12.0- 9.0*B- 6.0*C)/6.0)
#define	Q0   (( 8.0*B+24.0*C)/6.0)
#define	Q1   (( -12.0*B-48.0*C)/6.0)
#define	Q2   (( 6.0*B+30.0*C)/6.0)
#define	Q3   (( - 1.0*B- 6.0*C)/6.0)
Functions
float	BlitzScaleFilter::Bessel (const float x, const float)
float	BlitzScaleFilter::BesselOrderOne (float x)
float	BlitzScaleFilter::Blackman (const float x, const float)
float	BlitzScaleFilter::BlackmanBessel (const float x, const float support)
float	BlitzScaleFilter::BlackmanSinc (const float x, const float support)
float	BlitzScaleFilter::Box (const float x, const float)
float	BlitzScaleFilter::Catrom (const float x, const float)
float	BlitzScaleFilter::Cubic (const float x, const float)
float	BlitzScaleFilter::Gaussian (const float x, const float)
float	BlitzScaleFilter::Hamming (const float x, const float)
float	BlitzScaleFilter::Hanning (const float x, const float)
float	BlitzScaleFilter::Hermite (const float x, const float)
bool	BlitzScaleFilter::horizontalFilter (QImage *srcImg, QImage *destImg, float x_factor, float blur, ContributionInfo *contribution, Blitz::ScaleFilterType filter)
float	BlitzScaleFilter::J1 (float x)
float	BlitzScaleFilter::Lanczos (const float x, const float support)
float	BlitzScaleFilter::Mitchell (const float x, const float)
float	BlitzScaleFilter::P1 (float x)
float	BlitzScaleFilter::Q1 (float x)
float	BlitzScaleFilter::Quadratic (const float x, const float)
float	BlitzScaleFilter::Sinc (const float x, const float)
float	BlitzScaleFilter::Triangle (const float x, const float)
bool	BlitzScaleFilter::verticalFilter (QImage *srcImg, QImage *destImg, float y_factor, float blur, ContributionInfo *contribution, Blitz::ScaleFilterType filter)
Variables
static const float	BlitzScaleFilter::filterSupport [Blitz::SincFilter+1]
static const float	BlitzScaleFilter::J1Pone []
static const float	BlitzScaleFilter::J1Qone []
static const float	BlitzScaleFilter::P1Pone []
static const float	BlitzScaleFilter::P1Qone []
static const float	BlitzScaleFilter::Q1Pone []
static const float	BlitzScaleFilter::Q1Qone []

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Define Documentation

#define B   (1.0/3.0)

#define C   (1.0/3.0)

#define MagickEpsilon   1.0e-6

This is a port of the ImageMagick scaling functions from resize.c.

The most signficant change is ImageMagick uses a function pointer for the filter type. This is called usually a couple times in a loop for each horizontal and vertical coordinate. I changed this into a switch statement that does each type with inline functions. More code but faster.

Definition at line 70 of file scalefilter.cpp.

#define MagickPI   3.14159265358979323846264338327950288419716939937510

Definition at line 71 of file scalefilter.cpp.

#define P0   (( 6.0- 2.0*B )/6.0)

#define P2   ((-18.0+12.0*B+ 6.0*C)/6.0)

#define P3   (( 12.0- 9.0*B- 6.0*C)/6.0)

#define Q0   (( 8.0*B+24.0*C)/6.0)

#define Q1   (( -12.0*B-48.0*C)/6.0)

#define Q2   (( 6.0*B+30.0*C)/6.0)

#define Q3   (( - 1.0*B- 6.0*C)/6.0)