rawTherapee/rtengine/wavelet.h

313 lines
7.2 KiB
C++

/*
* This file is part of RawTherapee.
*
* RawTherapee is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* RawTherapee is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with RawTherapee. If not, see <http://www.gnu.org/licenses/>.
*
* 2010 Ilya Popov <ilia_popov@rambler.ru>
*/
#ifndef WAVELET_H_INCLUDED
#define WAVELET_H_INCLUDED
/////////////////////////////////////////////////////////////////////////////
// Haar wavelets //
/////////////////////////////////////////////////////////////////////////////
// Bad, strong block effect
template<typename T>
void dwt_haar(T * data, size_t pitch, T * buffer, size_t n)
{
size_t n2a = (n + 1) / 2;
size_t n2 = n/2;
for(size_t i = 0, j = 0; i < n2; i++, j += 2 * pitch)
{
T a = data[j];
T b = data[j + pitch];
buffer[i] = (a + b) / 2;
buffer[n2a + i] = (a - b);
}
if(n2 < n2a)
{
buffer[n2] = data[pitch * (n-1)];
}
for(size_t k = 0, q = 0; k < n; k++, q += pitch)
{
data[q] = buffer[k];
}
}
template<typename T>
void idwt_haar(T * data, size_t pitch, T * buffer, size_t n, int alpha)
{
size_t n2a = (n + 1) / 2;
size_t n2 = n/2;
for(size_t i = 0, j = 0; i < n2; i++, j += 2)
{
T p = data[i * pitch];
T q = (alpha * data[(n2a + i)*pitch]) / 1024;
buffer[j] = p + q / 2;
buffer[j + 1] = p - q / 2;
}
if(n2 < n2a)
{
buffer[n-1] = data[pitch * n2];
}
for(size_t k = 0, q = 0; k < n; k++, q += pitch)
{
data[q] = buffer[k];
}
}
/////////////////////////////////////////////////////////////////////////////
// CDF 5/3 wavelets //
/////////////////////////////////////////////////////////////////////////////
// buffer must be of length (n + 4)
template<typename T>
void dwt_53(T * data, size_t pitch, T * buffer, size_t n)
{
size_t n2 = n/2;
size_t n2a = (n + 1) / 2;
T * tmp = buffer + 2;
// copy data
for(size_t i = 0, j = 0; i < n; i++, j += pitch)
{
tmp[i] = data[j];
}
// extend mirror-like
tmp[-1] = tmp[1];
tmp[-2] = tmp[2];
tmp[n] = tmp[n-2];
tmp[n+1] = tmp[n-3];
// calculate coefficients
for(ptrdiff_t i = -1; i < (ptrdiff_t)n + 1; i += 2)
{
tmp[i] = tmp[i] - (tmp[i-1] + tmp[i+1]) / 2;
}
for(ptrdiff_t i = 0; i < (ptrdiff_t)n; i += 2)
{
tmp[i] = tmp[i] + (tmp[i-1] + tmp[i+1] + 2) / 4;
}
// copy with reordering
for(size_t i = 0, j = 0; i < n; i+=2, j += pitch)
{
data[j] = tmp[i];
}
for(size_t i = 1, j = n2a*pitch; i < n; i+=2, j += pitch)
{
data[j] = tmp[i];
}
}
template<typename T>
void idwt_53(T * data, size_t pitch, T * buffer, size_t n, int alpha)
{
size_t n2 = n/2;
size_t n2a = (n + 1) / 2;
T * tmp = buffer + 2;
// copy with reordering
for(size_t i = 0, j = 0; i < n; i+=2, j += pitch)
{
tmp[i] = data[j];
}
for(size_t i = 1, j = n2a*pitch; i < n; i+=2, j += pitch)
{
tmp[i] = (alpha * data[j]) / 1024;
}
// extend mirror-like
tmp[-1] = tmp[1];
tmp[-2] = tmp[2];
tmp[n] = tmp[n-2];
tmp[n+1] = tmp[n-3];
// calculate coefficients
for(ptrdiff_t i = 0; i < (ptrdiff_t)n + 1; i += 2)
{
tmp[i] = tmp[i] - (tmp[i-1] + tmp[i+1] + 2) / 4;
}
for(ptrdiff_t i = 1; i < (ptrdiff_t)n; i += 2)
{
tmp[i] = tmp[i] + (tmp[i-1] + tmp[i+1]) / 2;
}
// copy data
for(size_t i = 0, j = 0; i < n; i++, j += pitch)
{
data[j] = tmp[i];
}
}
/////////////////////////////////////////////////////////////////////////////
// Edge-avoiding wavelets //
/////////////////////////////////////////////////////////////////////////////
// based on
// Edge-Avoiding Wavelets and their Applications
// Raanan Fattal <raananf@cs.huji.ac.il>,
// Hebrew University of Jerusalem, Israel
//
// WCDF variant from this paper is used here
// T must be one of floating-point types
/////////////////////////////////////////////////////////////////////////////
template<typename T>
inline T wcdf_weight(T a, T b)
{
static const T eps = 1;
static const T one = 1.0;
return one / (fabs(a - b) + eps);
}
// buffer is a temporary storage
// buffer2 must be preserved between dwt and idwt
template<typename T>
void dwt_wcdf(T * data, size_t pitch, T * buffer, size_t n, T * buffer2)
{
size_t n2 = n/2;
size_t n2a = (n + 1) / 2;
T * tmp = buffer + 2;
T * w = buffer2 + 2;
// copy data
for(size_t i = 0, j = 0; i < n; i++, j += pitch)
{
tmp[i] = data[j];
}
// extend mirror-like
tmp[-1] = tmp[1];
tmp[-2] = tmp[2];
tmp[n] = tmp[n-2];
tmp[n+1] = tmp[n-3];
// calculate weights
for(ptrdiff_t i = 0; i < (ptrdiff_t)n - 1; i++)
{
w[i] = wcdf_weight(tmp[i], tmp[i+1]);
//w[i] = 1;
}
w[-1] = w[-2] = (T)0.0;
w[n-1] = w[n] = w[n + 1] = (T)0.0;
// calculate coefficients
for(ptrdiff_t i = 1; i < (ptrdiff_t)n; i += 2)
{
tmp[i] = tmp[i] - (w[i-1]*tmp[i-1] + w[i]*tmp[i+1]) / (w[i-1] + w[i]);
}
for(ptrdiff_t i = 0; i < (ptrdiff_t)n; i += 2)
{
tmp[i] = tmp[i] + (T)0.5 * (w[i-1]*tmp[i-1] + w[i]*tmp[i+1]) / (w[i-1] + w[i]);
}
// copy with reordering
for(size_t i = 0, j = 0; i < n; i+=2, j += pitch)
{
data[j] = tmp[i];
}
for(size_t i = 1, j = n2a*pitch; i < n; i+=2, j += pitch)
{
data[j] = tmp[i];
}
}
template<typename T>
void idwt_wcdf(T * data, size_t pitch, T * buffer, size_t n, int alpha, T * buffer2)
{
size_t n2 = n/2;
size_t n2a = (n + 1) / 2;
T * tmp = buffer + 2;
T * w = buffer2 + 2;
// copy with reordering
for(size_t i = 0, j = 0; i < n; i+=2, j += pitch)
{
tmp[i] = data[j];
}
for(size_t i = 1, j = n2a*pitch; i < n; i+=2, j += pitch)
{
tmp[i] = (alpha * data[j]) / 1024;
}
// extend mirror-like
tmp[-1] = tmp[1];
tmp[-2] = tmp[2];
tmp[n] = tmp[n-2];
tmp[n+1] = tmp[n-3];
// calculate coefficients
for(ptrdiff_t i = 0; i < (ptrdiff_t)n; i += 2)
{
tmp[i] = tmp[i] - (T)0.5 * (w[i-1]*tmp[i-1] + w[i]*tmp[i+1]) / (w[i-1] + w[i]);
}
for(ptrdiff_t i = 1; i < (ptrdiff_t)n; i += 2)
{
tmp[i] = tmp[i] + (w[i-1]*tmp[i-1] + w[i]*tmp[i+1]) / (w[i-1] + w[i]);
}
// copy data
for(size_t i = 0, j = 0; i < n; i++, j += pitch)
{
data[j] = tmp[i];
}
}
//////////////////////////////////////////////////////////////////////////////
#endif