rawTherapee/rtengine/histmatching.cc
2019-09-10 12:34:57 +02:00

399 lines
13 KiB
C++

/* -*- C++ -*-
*
* This file is part of RawTherapee.
*
* Copyright (c) 2018 Alberto Griggio <alberto.griggio@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 "rawimagesource.h"
#include "rtthumbnail.h"
#include "curves.h"
#include "color.h"
#include "rt_math.h"
#include "iccstore.h"
#include "procparams.h"
#include "../rtgui/mydiagonalcurve.h"
#include "improcfun.h"
//#define BENCHMARK
#include "StopWatch.h"
#include <iostream>
namespace rtengine {
extern const Settings *settings;
namespace {
struct CdfInfo {
std::vector<int> cdf;
int min_val;
int max_val;
CdfInfo(): cdf(256), min_val(-1), max_val(-1) {}
};
CdfInfo getCdf(const IImage8 &img)
{
CdfInfo ret;
for (int y = 0; y < img.getHeight(); ++y) {
for (int x = 0; x < img.getWidth(); ++x) {
int lum = LIM(int(Color::rgbLuminance(float(img.r(y, x)), float(img.g(y, x)), float(img.b(y, x)))), 0, 255);
++ret.cdf[lum];
}
}
int sum = 0;
for (size_t i = 0; i < ret.cdf.size(); ++i) {
if (ret.cdf[i] > 0) {
if (ret.min_val < 0) {
ret.min_val = i;
}
ret.max_val = i;
}
sum += ret.cdf[i];
ret.cdf[i] = sum;
}
return ret;
}
int findMatch(int val, const std::vector<int> &cdf, int j)
{
if (cdf[j] <= val) {
for (; j < int(cdf.size()); ++j) {
if (cdf[j] == val) {
return j;
} else if (cdf[j] > val) {
return (cdf[j] - val <= val - cdf[j-1] ? j : j-1);
}
}
return 255;
} else {
for (; j >= 0; --j) {
if (cdf[j] == val) {
return j;
} else if (cdf[j] < val) {
return (val - cdf[j] <= cdf[j+1] - val ? j : j+1);
}
}
return 0;
}
}
void mappingToCurve(const std::vector<int> &mapping, std::vector<double> &curve)
{
curve.clear();
int idx = 15;
for (; idx < int(mapping.size()); ++idx) {
if (mapping[idx] >= idx) {
break;
}
}
if (idx == int(mapping.size())) {
for (idx = 1; idx < int(mapping.size())-1; ++idx) {
if (mapping[idx] >= idx) {
break;
}
}
}
auto coord = [](int v) -> double { return double(v)/255.0; };
auto doit =
[&](int start, int stop, int step, bool addstart, int maxdelta=0) -> void
{
if (!maxdelta) maxdelta = step * 2;
int prev = start;
if (addstart && mapping[start] >= 0) {
curve.push_back(coord(start));
curve.push_back(coord(mapping[start]));
}
for (int i = start; i < stop; ++i) {
int v = mapping[i];
if (v < 0) {
continue;
}
bool change = i > 0 && v != mapping[i-1];
int diff = i - prev;
if ((change && std::abs(diff - step) <= 1) || diff > maxdelta) {
curve.push_back(coord(i));
curve.push_back(coord(v));
prev = i;
}
}
};
curve.push_back(0.0);
curve.push_back(0.0);
int start = 0;
while (start < idx && (mapping[start] < 0 || start < idx / 2)) {
++start;
}
const int npoints = 8;
int step = std::max(int(mapping.size())/npoints, 1);
int end = mapping.size();
if (idx <= end / 3) {
doit(start, idx, idx / 2, true);
step = (end - idx) / 4;
doit(idx, end, step, false, step);
} else {
doit(start, idx, idx > step ? step : idx / 2, true);
doit(idx, end, step, idx - step > step / 2 && std::abs(curve[curve.size()-2] - coord(idx)) > 0.01);
}
if (curve.size() > 2 && (1 - curve[curve.size()-2] <= coord(step) / 3)) {
curve.pop_back();
curve.pop_back();
}
curve.push_back(1.0);
curve.push_back(1.0);
// we assume we are matching an S-shaped curve, so try to avoid
// concavities in the upper part of the S
const auto getpos =
[](float x, float xa, float ya, float xb, float yb)
{
// line equation:
// (x - xa) / (xb - xa) = (y - ya) / (yb - ya)
return (x - xa) / (xb - xa) * (yb - ya) + ya;
};
idx = -1;
for (ssize_t i = curve.size()-1; i > 0; i -= 2) {
if (curve[i] <= 0.f) {
idx = i+1;
break;
}
}
if (idx >= 0 && size_t(idx) < curve.size()) {
// idx is the position of the first point in the upper part of the S
// for each 3 consecutive points (xa, ya), (x, y), (xb, yb) we check
// that y is above the point at x of the line between the other two
// if this is not the case, we remove (x, y) from the curve
while (size_t(idx+5) < curve.size()) {
float xa = curve[idx];
float ya = curve[idx+1];
float x = curve[idx+2];
float y = curve[idx+3];
float xb = curve[idx+4];
float yb = curve[idx+5];
float yy = getpos(x, xa, ya, xb, yb);
if (yy > y) {
// we have to remove (x, y) from the curve
curve.erase(curve.begin()+(idx+2), curve.begin()+(idx+4));
} else {
// move on to the next point
idx += 2;
}
}
}
if (curve.size() < 4) {
curve = { DCT_Linear }; // not enough points, fall back to linear
} else {
curve.insert(curve.begin(), DCT_Spline);
DiagonalCurve c(curve);
double gap = 0.05;
double x = 0.0;
curve = { DCT_CatumullRom };
while (x < 1.0) {
curve.push_back(x);
curve.push_back(c.getVal(x));
x += gap;
gap *= 1.4;
}
curve.push_back(1.0);
curve.push_back(c.getVal(1.0));
}
}
} // namespace
void RawImageSource::getAutoMatchedToneCurve(const ColorManagementParams &cp, std::vector<double> &outCurve)
{
BENCHFUN
if (settings->verbose) {
std::cout << "performing histogram matching for " << getFileName() << " on the embedded thumbnail" << std::endl;
}
const auto same_profile =
[](const ColorManagementParams &a, const ColorManagementParams &b) -> bool
{
return (a.inputProfile == b.inputProfile
&& a.toneCurve == b.toneCurve
&& a.applyLookTable == b.applyLookTable
&& a.applyBaselineExposureOffset == b.applyBaselineExposureOffset
&& a.applyHueSatMap == b.applyHueSatMap
&& a.dcpIlluminant == b.dcpIlluminant);
};
if (!histMatchingCache.empty() && same_profile(*histMatchingParams, cp)) {
if (settings->verbose) {
std::cout << "tone curve found in cache" << std::endl;
}
outCurve = histMatchingCache;
return;
}
outCurve = { DCT_Linear };
int fw, fh;
getFullSize(fw, fh, TR_NONE);
if (getRotateDegree() == 90 || getRotateDegree() == 270) {
std::swap(fw, fh);
}
int skip = 3;
if (settings->verbose) {
std::cout << "histogram matching: full raw image size is " << fw << "x" << fh << std::endl;
}
ProcParams neutral;
neutral.icm = cp;
neutral.raw.bayersensor.method = RAWParams::BayerSensor::getMethodString(RAWParams::BayerSensor::Method::FAST);
neutral.raw.xtranssensor.method = RAWParams::XTransSensor::getMethodString(RAWParams::XTransSensor::Method::FAST);
neutral.icm.outputProfile = ColorManagementParams::NoICMString;
std::unique_ptr<IImage8> source;
{
RawMetaDataLocation rml;
eSensorType sensor_type;
int w, h;
std::unique_ptr<Thumbnail> thumb(Thumbnail::loadQuickFromRaw(getFileName(), rml, sensor_type, w, h, 1, false, true, true));
if (!thumb) {
if (settings->verbose) {
std::cout << "histogram matching: no thumbnail found, generating a neutral curve" << std::endl;
}
histMatchingCache = outCurve;
*histMatchingParams = cp;
return;
} else if (w * 33 < fw || w * h < 19200) {
// Some cameras have extremely small thumbs, for example Canon PowerShot A3100 IS has 128x96 thumbs.
// For them we skip histogram matching.
// With 160x120 thumbs from RICOH GR DIGITAL 2 it works fine, so we use 19200 as limit.
if (settings->verbose) {
std::cout << "histogram matching: the embedded thumbnail is too small: " << w << "x" << h << std::endl;
}
histMatchingCache = outCurve;
*histMatchingParams = cp;
return;
}
skip = LIM(skip * fh / h, 6, 10); // adjust the skip factor -- the larger the thumbnail, the less we should skip to get a good match
source.reset(thumb->quickProcessImage(neutral, fh / skip, TI_Nearest));
if (settings->verbose) {
std::cout << "histogram matching: extracted embedded thumbnail" << std::endl;
}
}
std::unique_ptr<IImage8> target;
{
RawMetaDataLocation rml;
eSensorType sensor_type;
double scale;
int w = fw / skip, h = fh / skip;
std::unique_ptr<Thumbnail> thumb(Thumbnail::loadFromRaw(getFileName(), rml, sensor_type, w, h, 1, false, false, true));
if (!thumb) {
if (settings->verbose) {
std::cout << "histogram matching: raw decoding failed, generating a neutral curve" << std::endl;
}
histMatchingCache = outCurve;
*histMatchingParams = cp;
return;
}
target.reset(thumb->processImage(neutral, sensor_type, fh / skip, TI_Nearest, getMetaData(), scale, false, true));
int sw = source->getWidth(), sh = source->getHeight();
int tw = target->getWidth(), th = target->getHeight();
float thumb_ratio = float(std::max(sw, sh)) / float(std::min(sw, sh));
float target_ratio = float(std::max(tw, th)) / float(std::min(tw, th));
if (std::abs(thumb_ratio - target_ratio) > 0.01) {
int cx = 0, cy = 0;
if (thumb_ratio > target_ratio) {
// crop the height
int ch = th - (tw * float(sh) / float(sw));
cy += ch / 2;
th -= ch;
} else {
// crop the width
int cw = tw - (th * float(sw) / float(sh));
cx += cw / 2;
tw -= cw;
}
if (settings->verbose) {
std::cout << "histogram matching: cropping target to get an aspect ratio of " << round(thumb_ratio * 100)/100.0 << ":1, new size is " << tw << "x" << th << std::endl;
}
if (cx || cy) {
Image8 *tmp = new Image8(tw, th);
#ifdef _OPENMP
#pragma omp parallel for
#endif
for (int y = 0; y < th; ++y) {
for (int x = 0; x < tw; ++x) {
tmp->r(y, x) = target->r(y+cy, x+cx);
tmp->g(y, x) = target->g(y+cy, x+cx);
tmp->b(y, x) = target->b(y+cy, x+cx);
}
}
target.reset(tmp);
}
}
if (settings->verbose) {
std::cout << "histogram matching: generated neutral rendering" << std::endl;
}
}
if (target->getWidth() != source->getWidth() || target->getHeight() != source->getHeight()) {
Image8 *tmp = new Image8(source->getWidth(), source->getHeight());
target->resizeImgTo(source->getWidth(), source->getHeight(), TI_Nearest, tmp);
target.reset(tmp);
}
CdfInfo scdf = getCdf(*source);
CdfInfo tcdf = getCdf(*target);
std::vector<int> mapping;
int j = 0;
for (int i = 0; i < int(tcdf.cdf.size()); ++i) {
j = findMatch(tcdf.cdf[i], scdf.cdf, j);
if (i >= tcdf.min_val && i <= tcdf.max_val && j >= scdf.min_val && j <= scdf.max_val) {
mapping.push_back(j);
} else {
mapping.push_back(-1);
}
}
mappingToCurve(mapping, outCurve);
if (settings->verbose) {
std::cout << "histogram matching: generated curve with " << outCurve.size()/2 << " control points" << std::endl;
}
histMatchingCache = outCurve;
*histMatchingParams = cp;
}
} // namespace rtengine