Homec4science
Diffusion RADIANCE Photon Map (fixSpecular) Browse

RadiancePmap/wavelet.h
d89403d28f6ffixSpecular

Last Change
Raw File

wavelet.h
View Options

/*
=========================================================================
1D wavelet transform on arbitrary sized arrays (i.e. not restricted to
powers of 2) of double 3-tuples. Array boundaries are extended as
constants.
Roland Schregle (roland.schregle@{hslu.ch, gmail.com})
(c) Lucerne University of Applied Sciences and Arts,
supported by the Swiss National Science Foundation
(SNSF #179067, "Light Fields for Spatio-Temporal Glare Assessment")
=========================================================================
$Id$
*/
#ifndef _PMAP_WAVELET_H
#define _PMAP_WAVELET_H
typedef double Coeff;
unsigned waveletXform (Coeff (*x) [3], unsigned xLen, Coeff (*y) [3]);
/* Perform full multiresolution forward wavelet transform
on array x of length xLen containing 3-tuples. Note no intra-tuple
transform occurs (1-D only).
The wavelet coefficients are returned in preallocated array y, containing
the coarsest approximation in y [0] followed by details in order of
increasing resolution/frequency.
Note y must accommodate more than xLen coefficients to accommodate
padding for additional boundary coefficients. The number of coefficients
can be interrogated beforehand by calling the function with either x or y
set to NULL.
Note also that x is used as a buffer for intermediate results, and is
therefore modified.
The returned value is the number of output coefficients in y, or 0 if the
transform failed, e.g. if the input is too short.
*/
unsigned waveletInvXform (Coeff (*y) [3], unsigned yLen,
Coeff (*x) [3], unsigned xLen0
);
/* Perform full multiresolution inverse wavelet transform on array y of
* length yLen containing wavelet coefficients as 3-tuples. Note no
* intra-tuple transform occurs (1-D only). The original signal length xLen0
* is required for the reconstruction.
*
* The reconstructed signal is returned in the preallocated array x. This
* is shorter than yLen since the additional boundary coefficients in y are
* collapsed. Note y is used as buffer for intermediate results, and is
* therefore modified.
*
* The returned value is the reconstructed signal length, which should match
* xLen, or 0 if the transform failed.
*/
#endif
c4science · Help