Documentation - C API
homkermap.c File Reference

Homogeneous kernel map - Definition. More...

#include "homkermap.h"
#include "mathop.h"
#include <math.h>
#include "homkermap.c"

Functions

double vl_homogeneouskernelmap_get_spectrum (VlHomogeneousKernelMap const *self, double omega)
 Sample the kernel specturm.
double vl_homogeneouskernelmap_get_smooth_spectrum (VlHomogeneousKernelMap const *self, double omega)
 Sample the smoothed kernel spectrum.
VlHomogeneousKernelMapvl_homogeneouskernelmap_new (VlHomogeneousKernelType kernelType, double gamma, vl_size order, double period, VlHomogeneousKernelMapWindowType windowType)
 Create a new homgeneous kernel map.
void vl_homogeneouskernelmap_delete (VlHomogeneousKernelMap *self)
 Delete a map object.

Detailed Description

Author:
Andrea Vedaldi

Function Documentation

void vl_homogeneouskernelmap_delete ( VlHomogeneousKernelMap self)
Parameters:
selfmap object. The function deletes the specified map object.
double vl_homogeneouskernelmap_get_smooth_spectrum ( VlHomogeneousKernelMap const *  self,
double  omega 
) [inline]
Parameters:
selfhomogeneous kernel map.
omegasampling frequency.
Returns:
the spectrum sampled at omega after smoothing.
double vl_homogeneouskernelmap_get_spectrum ( VlHomogeneousKernelMap const *  self,
double  omega 
) [inline]
Parameters:
selfhomogeneous kernel map.
omegasampling frequency.
Returns:
the spectrum sampled at omega.
VlHomogeneousKernelMap* vl_homogeneouskernelmap_new ( VlHomogeneousKernelType  kernelType,
double  gamma,
vl_size  order,
double  period,
VlHomogeneousKernelMapWindowType  windowType 
)
Parameters:
kernelTypetype of homogeneous kernel.
gammakernel homogeneity degree.
orderapproximation order.
periodkernel period.
windowTypetype of window used to truncate the kernel.
Returns:
the new homogeneous kernel map.

The function intializes a new homogeneous kernel map for the specified kernel type, homogeneity degree, approximation order, period, and truncation window. See Overview for details.

The homogeneity degree gamma must be positive (the standard kernels are obtained by setting gamma to 1). When unsure, set windowType to VlHomogeneousKernelMapWindowRectangular. The period should be non-negative; specifying a negative or null value causes the function to switch to a default value.

The function returns NULL if there is not enough free memory.