rawTherapee/rtengine/filmnegativethumb.cc
2019-11-03 17:03:40 +01:00

125 lines
4.1 KiB
C++

/*
* This file is part of RawTherapee.
*
* Copyright (c) 2019 Alberto Romei <aldrop8@gmail.com>
*
* 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 <https://www.gnu.org/licenses/>.
*/
#include <cmath>
#include "LUT.h"
#include "rtengine.h"
#include "rtthumbnail.h"
#include "opthelper.h"
#include "sleef.h"
#include "rt_algo.h"
#include "settings.h"
#include "procparams.h"
#define BENCHMARK
#include "StopWatch.h"
void rtengine::Thumbnail::processFilmNegative(
const procparams::ProcParams &params,
const Imagefloat* baseImg,
const int rwidth, const int rheight,
float &rmi, float &gmi, float &bmi
) {
// Channel exponents
const float rexp = -params.filmNegative.redRatio * params.filmNegative.greenExp;
const float gexp = -params.filmNegative.greenExp;
const float bexp = -params.filmNegative.blueRatio * params.filmNegative.greenExp;
// Need to calculate channel averages, to fake the same conditions
// found in rawimagesource, where get_ColorsCoeff is called with
// forceAutoWB=true.
float rsum = 0.f, gsum = 0.f, bsum = 0.f;
// Channel vectors to calculate medians
std::vector<float> rv, gv, bv;
for (int i = 0; i < rheight; i++) {
for (int j = 0; j < rwidth; j++) {
const float r = baseImg->r(i, j);
const float g = baseImg->g(i, j);
const float b = baseImg->b(i, j);
rsum += r;
gsum += g;
bsum += b;
rv.push_back(r);
gv.push_back(g);
bv.push_back(b);
}
}
const float ravg = rsum / (rheight*rwidth);
const float gavg = gsum / (rheight*rwidth);
const float bavg = bsum / (rheight*rwidth);
// Shifting current WB multipliers, based on channel averages.
rmi /= (gavg/ravg);
// gmi /= (gAvg/gAvg); green chosen as reference channel
bmi /= (gavg/bavg);
float rmed, gmed, bmed;
findMinMaxPercentile(rv.data(), rv.size(), 0.5f, rmed, 0.5f, rmed, true);
findMinMaxPercentile(gv.data(), gv.size(), 0.5f, gmed, 0.5f, gmed, true);
findMinMaxPercentile(bv.data(), bv.size(), 0.5f, bmed, 0.5f, bmed, true);
rmed = powf(rmed, rexp);
gmed = powf(gmed, gexp);
bmed = powf(bmed, bexp);
const float MAX_OUT_VALUE = 65000.f;
const float rmult = (MAX_OUT_VALUE / (rmed * 24)) ;
const float gmult = (MAX_OUT_VALUE / (gmed * 24)) ;
const float bmult = (MAX_OUT_VALUE / (bmed * 24)) ;
if (settings->verbose) {
printf("Thumbnail channel medians: %g %g %g\n", rmed, gmed, bmed);
printf("Thumbnail computed multipliers: %g %g %g\n", rmult, gmult, bmult);
}
#ifdef __SSE2__
const vfloat clipv = F2V(MAXVALF);
const vfloat rexpv = F2V(rexp);
const vfloat gexpv = F2V(gexp);
const vfloat bexpv = F2V(bexp);
const vfloat rmultv = F2V(rmult);
const vfloat gmultv = F2V(gmult);
const vfloat bmultv = F2V(bmult);
#endif
for (int i = 0; i < rheight; i++) {
float *rline = baseImg->r(i);
float *gline = baseImg->g(i);
float *bline = baseImg->b(i);
int j = 0;
#ifdef __SSE2__
for (; j < rwidth - 3; j +=4) {
STVFU(rline[j], vminf(rmultv * pow_F(LVFU(rline[j]), rexpv), clipv));
STVFU(gline[j], vminf(gmultv * pow_F(LVFU(gline[j]), gexpv), clipv));
STVFU(bline[j], vminf(bmultv * pow_F(LVFU(bline[j]), bexpv), clipv));
}
#endif
for (; j < rwidth; ++j) {
rline[j] = CLIP(rmult * pow_F(rline[j], rexp));
gline[j] = CLIP(gmult * pow_F(gline[j], gexp));
bline[j] = CLIP(bmult * pow_F(bline[j], bexp));
}
}
}