Exposure fusion. Code, tests.

This commit is contained in:
Fedor Morozov 2013-07-05 16:14:08 +04:00
parent a5e11079d7
commit 0aee5b61e3
4 changed files with 232 additions and 131 deletions

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@ -96,8 +96,10 @@ CV_EXPORTS_W void fastNlMeansDenoisingColoredMulti( InputArrayOfArrays srcImgs,
CV_EXPORTS_W void makeHDR(InputArrayOfArrays srcImgs, const std::vector<float>& exp_times, OutputArray dst);
CV_EXPORTS_W void tonemap(InputArray src, OutputArray dst, tonemap_algorithms algorithm, std::vector<float>& params = std::vector<float>());
CV_EXPORTS_W void tonemap(InputArray src, OutputArray dst, tonemap_algorithms algorithm,
const std::vector<float>& params = std::vector<float>());
CV_EXPORTS_W void exposureFusion(InputArrayOfArrays srcImgs, OutputArray dst, float wc = 1, float ws = 1, float we = 0);
} // cv
#endif

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@ -64,14 +64,12 @@ static void generateResponce(float responce[])
responce[0] = responce[1];
}
void makeHDR(InputArrayOfArrays _images, const std::vector<float>& _exp_times, OutputArray _dst)
static void checkImages(std::vector<Mat>& images, bool hdr, const std::vector<float>& _exp_times = std::vector<float>())
{
std::vector<Mat> images;
_images.getMatVector(images);
if(images.empty()) {
CV_Error(Error::StsBadArg, "Need at least one image");
}
if(images.size() != _exp_times.size()) {
if(hdr && images.size() != _exp_times.size()) {
CV_Error(Error::StsBadArg, "Number of images and number of exposure times must be equal.");
}
int width = images[0].cols;
@ -85,8 +83,16 @@ void makeHDR(InputArrayOfArrays _images, const std::vector<float>& _exp_times, O
CV_Error(Error::StsBadArg, "Images must have CV_8UC3 type.");
}
}
}
void makeHDR(InputArrayOfArrays _images, const std::vector<float>& _exp_times, OutputArray _dst)
{
std::vector<Mat> images;
_images.getMatVector(images);
checkImages(images, true, _exp_times);
_dst.create(images[0].size(), CV_32FC3);
Mat result = _dst.getMat();
std::vector<float> exp_times(_exp_times.size());
for(size_t i = 0; i < exp_times.size(); i++) {
exp_times[i] = log(_exp_times[i]);
@ -122,4 +128,88 @@ void makeHDR(InputArrayOfArrays _images, const std::vector<float>& _exp_times, O
result = result / max;
}
void exposureFusion(InputArrayOfArrays _images, OutputArray _dst, float wc, float ws, float we)
{
std::vector<Mat> images;
_images.getMatVector(images);
checkImages(images, false);
std::vector<Mat> weights(images.size());
Mat weight_sum = Mat::zeros(images[0].size(), CV_32FC1);
for(size_t im = 0; im < images.size(); im++) {
Mat img, gray, contrast, saturation, wellexp;
std::vector<Mat> channels(3);
images[im].convertTo(img, CV_32FC3, 1.0/255.0);
cvtColor(img, gray, COLOR_RGB2GRAY);
split(img, channels);
Laplacian(gray, contrast, CV_32F);
contrast = abs(contrast);
Mat mean = (channels[0] + channels[1] + channels[2]) / 3.0f;
saturation = Mat::zeros(channels[0].size(), CV_32FC1);
for(int i = 0; i < 3; i++) {
Mat deviation = channels[i] - mean;
pow(deviation, 2.0, deviation);
saturation += deviation;
}
sqrt(saturation, saturation);
wellexp = Mat::ones(gray.size(), CV_32FC1);
for(int i = 0; i < 3; i++) {
Mat exp = channels[i] - 0.5f;
pow(exp, 2, exp);
exp = -exp / 0.08;
wellexp = wellexp.mul(exp);
}
pow(contrast, wc, contrast);
pow(saturation, ws, saturation);
pow(wellexp, we, wellexp);
weights[im] = contrast;
weights[im] = weights[im].mul(saturation);
weights[im] = weights[im].mul(wellexp);
weight_sum += weights[im];
}
int maxlevel = (int)(log((double)max(images[0].rows, images[0].cols)) / log(2.0)) - 1;
std::vector<Mat> res_pyr(maxlevel + 1);
for(size_t im = 0; im < images.size(); im++) {
weights[im] /= weight_sum;
Mat img;
images[im].convertTo(img, CV_32FC3, 1/255.0);
std::vector<Mat> img_pyr, weight_pyr;
buildPyramid(img, img_pyr, maxlevel);
buildPyramid(weights[im], weight_pyr, maxlevel);
for(int lvl = 0; lvl < maxlevel; lvl++) {
Mat up;
pyrUp(img_pyr[lvl + 1], up, img_pyr[lvl].size());
img_pyr[lvl] -= up;
}
for(int lvl = 0; lvl <= maxlevel; lvl++) {
std::vector<Mat> channels(3);
split(img_pyr[lvl], channels);
for(int i = 0; i < 3; i++) {
channels[i] = channels[i].mul(weight_pyr[lvl]);
}
merge(channels, img_pyr[lvl]);
if(res_pyr[lvl].empty()) {
res_pyr[lvl] = img_pyr[lvl];
} else {
res_pyr[lvl] += img_pyr[lvl];
}
}
}
for(int lvl = maxlevel; lvl > 0; lvl--) {
Mat up;
pyrUp(res_pyr[lvl], up, res_pyr[lvl - 1].size());
res_pyr[lvl - 1] += up;
}
_dst.create(images[0].size(), CV_32FC3);
Mat result = _dst.getMat();
res_pyr[0].copyTo(result);
}
};

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@ -45,146 +45,147 @@
namespace cv
{
static float getParam(std::vector<float>& params, size_t i, float defval)
{
if(params.size() > i) {
return params[i];
} else {
return defval;
}
}
static void DragoMap(Mat& src_img, Mat &dst_img, std::vector<float>& params)
{
float bias_value = getParam(params, 1, 0.85f);
Mat gray_img;
cvtColor(src_img, gray_img, COLOR_RGB2GRAY);
Mat log_img;
log(gray_img, log_img);
float mean = exp((float)sum(log_img)[0] / log_img.total());
gray_img /= mean;
log_img.release();
double max;
minMaxLoc(gray_img, NULL, &max);
static float getParam(const std::vector<float>& params, size_t i, float defval)
{
if(params.size() > i) {
return params[i];
} else {
return defval;
}
}
Mat map;
log(gray_img + 1.0f, map);
Mat div;
pow(gray_img / (float)max, log(bias_value) / log(0.5f), div);
log(2.0f + 8.0f * div, div);
map = map.mul(1.0f / div);
map = map.mul(1.0f / gray_img);
div.release();
gray_img.release();
static void DragoMap(Mat& src_img, Mat &dst_img, const std::vector<float>& params)
{
float bias_value = getParam(params, 1, 0.85f);
Mat gray_img;
cvtColor(src_img, gray_img, COLOR_RGB2GRAY);
Mat log_img;
log(gray_img, log_img);
float mean = exp((float)sum(log_img)[0] / log_img.total());
gray_img /= mean;
log_img.release();
std::vector<Mat> channels(3);
split(src_img, channels);
for(int i = 0; i < 3; i++) {
channels[i] = channels[i].mul(map);
}
map.release();
merge(channels, dst_img);
}
double max;
minMaxLoc(gray_img, NULL, &max);
static void ReinhardDevlinMap(Mat& src_img, Mat &dst_img, std::vector<float>& params)
{
float intensity = getParam(params, 1, 0.0f);
float color_adapt = getParam(params, 2, 0.0f);
float light_adapt = getParam(params, 3, 1.0f);
Mat map;
log(gray_img + 1.0f, map);
Mat div;
pow(gray_img / (float)max, log(bias_value) / log(0.5f), div);
log(2.0f + 8.0f * div, div);
map = map.mul(1.0f / div);
map = map.mul(1.0f / gray_img);
div.release();
gray_img.release();
Mat gray_img;
cvtColor(src_img, gray_img, COLOR_RGB2GRAY);
Mat log_img;
log(gray_img, log_img);
std::vector<Mat> channels(3);
split(src_img, channels);
for(int i = 0; i < 3; i++) {
channels[i] = channels[i].mul(map);
}
map.release();
merge(channels, dst_img);
}
float log_mean = (float)sum(log_img)[0] / log_img.total();
double log_min, log_max;
minMaxLoc(log_img, &log_min, &log_max);
log_img.release();
static void ReinhardDevlinMap(Mat& src_img, Mat &dst_img, const std::vector<float>& params)
{
float intensity = getParam(params, 1, 0.0f);
float color_adapt = getParam(params, 2, 0.0f);
float light_adapt = getParam(params, 3, 1.0f);
double key = (float)((log_max - log_mean) / (log_max - log_min));
float map_key = 0.3f + 0.7f * pow((float)key, 1.4f);
intensity = exp(-intensity);
Scalar chan_mean = mean(src_img);
float gray_mean = (float)mean(gray_img)[0];
Mat gray_img;
cvtColor(src_img, gray_img, COLOR_RGB2GRAY);
Mat log_img;
log(gray_img, log_img);
std::vector<Mat> channels(3);
split(src_img, channels);
float log_mean = (float)sum(log_img)[0] / log_img.total();
double log_min, log_max;
minMaxLoc(log_img, &log_min, &log_max);
log_img.release();
for(int i = 0; i < 3; i++) {
float global = color_adapt * (float)chan_mean[i] + (1.0f - color_adapt) * gray_mean;
Mat adapt = color_adapt * channels[i] + (1.0f - color_adapt) * gray_img;
adapt = light_adapt * adapt + (1.0f - light_adapt) * global;
pow(intensity * adapt, map_key, adapt);
channels[i] = channels[i].mul(1.0f / (adapt + channels[i]));
}
gray_img.release();
merge(channels, dst_img);
}
double key = (float)((log_max - log_mean) / (log_max - log_min));
float map_key = 0.3f + 0.7f * pow((float)key, 1.4f);
intensity = exp(-intensity);
Scalar chan_mean = mean(src_img);
float gray_mean = (float)mean(gray_img)[0];
static void DurandMap(Mat& src_img, Mat& dst_img, std::vector<float>& params)
{
float contrast = getParam(params, 1, 4.0f);
float sigma_color = getParam(params, 2, 2.0f);
float sigma_space = getParam(params, 3, 2.0f);
std::vector<Mat> channels(3);
split(src_img, channels);
Mat gray_img;
cvtColor(src_img, gray_img, COLOR_RGB2GRAY);
Mat log_img;
log(gray_img, log_img);
Mat map_img;
bilateralFilter(log_img, map_img, -1, sigma_color, sigma_space);
double min, max;
minMaxLoc(map_img, &min, &max);
float scale = contrast / (float)(max - min);
for(int i = 0; i < 3; i++) {
float global = color_adapt * (float)chan_mean[i] + (1.0f - color_adapt) * gray_mean;
Mat adapt = color_adapt * channels[i] + (1.0f - color_adapt) * gray_img;
adapt = light_adapt * adapt + (1.0f - light_adapt) * global;
pow(intensity * adapt, map_key, adapt);
channels[i] = channels[i].mul(1.0f / (adapt + channels[i]));
}
gray_img.release();
merge(channels, dst_img);
}
exp(map_img * (scale - 1.0f) + log_img, map_img);
log_img.release();
map_img = map_img.mul(1.0f / gray_img);
gray_img.release();
static void DurandMap(Mat& src_img, Mat& dst_img, const std::vector<float>& params)
{
float contrast = getParam(params, 1, 4.0f);
float sigma_color = getParam(params, 2, 2.0f);
float sigma_space = getParam(params, 3, 2.0f);
std::vector<Mat> channels(3);
split(src_img, channels);
for(int i = 0; i < 3; i++) {
channels[i] = channels[i].mul(map_img);
}
merge(channels, dst_img);
}
Mat gray_img;
cvtColor(src_img, gray_img, COLOR_RGB2GRAY);
Mat log_img;
log(gray_img, log_img);
Mat map_img;
bilateralFilter(log_img, map_img, -1, sigma_color, sigma_space);
double min, max;
minMaxLoc(map_img, &min, &max);
float scale = contrast / (float)(max - min);
void tonemap(InputArray _src, OutputArray _dst, tonemap_algorithms algorithm,
std::vector<float>& params)
{
typedef void (*tonemap_func)(Mat&, Mat&, std::vector<float>&);
const unsigned param_count[TONEMAP_COUNT] = {0, 1, 3, 3};
tonemap_func functions[TONEMAP_COUNT] = {
NULL, DragoMap, ReinhardDevlinMap, DurandMap};
exp(map_img * (scale - 1.0f) + log_img, map_img);
log_img.release();
map_img = map_img.mul(1.0f / gray_img);
gray_img.release();
Mat src = _src.getMat();
if(src.empty()) {
CV_Error(Error::StsBadArg, "Empty input image");
}
if(algorithm < 0 || algorithm >= TONEMAP_COUNT) {
CV_Error(Error::StsBadArg, "Wrong algorithm index");
}
std::vector<Mat> channels(3);
split(src_img, channels);
for(int i = 0; i < 3; i++) {
channels[i] = channels[i].mul(map_img);
}
merge(channels, dst_img);
}
_dst.create(src.size(), CV_32FC3);
Mat dst = _dst.getMat();
src.copyTo(dst);
void tonemap(InputArray _src, OutputArray _dst, tonemap_algorithms algorithm,
const std::vector<float>& params)
{
typedef void (*tonemap_func)(Mat&, Mat&, const std::vector<float>&);
tonemap_func functions[TONEMAP_COUNT] = {
NULL, DragoMap, ReinhardDevlinMap, DurandMap};
double min, max;
minMaxLoc(dst, &min, &max);
if(max - min < 1e-10f) {
return;
}
dst = (dst - min) / (max - min);
if(functions[algorithm]) {
functions[algorithm](dst, dst, params);
}
minMaxLoc(dst, &min, &max);
dst = (dst - min) / (max - min);
float gamma = getParam(params, 0, 1.0f);
pow(dst, 1.0f / gamma, dst);
}
Mat src = _src.getMat();
if(src.empty()) {
CV_Error(Error::StsBadArg, "Empty input image");
}
if(algorithm < 0 || algorithm >= TONEMAP_COUNT) {
CV_Error(Error::StsBadArg, "Wrong algorithm index");
}
_dst.create(src.size(), CV_32FC3);
Mat dst = _dst.getMat();
src.copyTo(dst);
double min, max;
minMaxLoc(dst, &min, &max);
if(max - min < 1e-10f) {
return;
}
dst = (dst - min) / (max - min);
if(functions[algorithm]) {
functions[algorithm](dst, dst, params);
}
minMaxLoc(dst, &min, &max);
dst = (dst - min) / (max - min);
float gamma = getParam(params, 0, 1.0f);
pow(dst, 1.0f / gamma, dst);
}
}

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@ -47,7 +47,7 @@
using namespace cv;
using namespace std;
TEST(Photo_MakeHdr, regression)
TEST(Photo_HdrFusion, regression)
{
string folder = string(cvtest::TS::ptr()->get_data_path()) + "hdr/";
@ -75,6 +75,14 @@ TEST(Photo_MakeHdr, regression)
double max = 1.0;
minMaxLoc(abs(result - expected), NULL, &max);
ASSERT_TRUE(max < 0.01);
expected_path = folder + "grand_canal_exp_fusion.png";
expected = imread(expected_path);
ASSERT_FALSE(expected.empty()) << "Could not load input image " << expected_path;
exposureFusion(images, result);
result.convertTo(result, CV_8UC3, 255);
minMaxLoc(abs(result - expected), NULL, &max);
ASSERT_FALSE(max > 0);
}
TEST(Photo_Tonemap, regression)