OpenCV_4.2.0/opencv_contrib-4.2.0/modules/quality/samples/brisque_eval_tid2008.cpp

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#include <fstream>
#include "opencv2/quality.hpp"
#include "opencv2/imgproc.hpp"
#include "opencv2/imgcodecs.hpp"
#include "opencv2/ml.hpp"
/*
BRISQUE evaluator using TID2008
TID2008:
http://www.ponomarenko.info/tid2008.htm
[1] N. Ponomarenko, V. Lukin, A. Zelensky, K. Egiazarian, M. Carli,
F. Battisti, "TID2008 - A Database for Evaluation of Full-Reference
Visual Quality Assessment Metrics", Advances of Modern
Radioelectronics, Vol. 10, pp. 30-45, 2009.
[2] N. Ponomarenko, F. Battisti, K. Egiazarian, J. Astola, V. Lukin
"Metrics performance comparison for color image database", Fourth
international workshop on video processing and quality metrics
for consumer electronics, Scottsdale, Arizona, USA. Jan. 14-16, 2009, 6 p.
*/
namespace {
// get ordinal ranks of data, fractional ranks assigned for ties. O(n^2) time complexity
// optional binary predicate used for rank ordering of data elements, equality evaluation
template <typename T, typename PrEqual = std::equal_to<T>, typename PrLess = std::less<T>>
std::vector<float> rank_ordinal(const T* data, std::size_t sz, PrEqual&& eq = {}, PrLess&& lt = {})
{
std::vector<float> result{};
result.resize(sz, -1);// set all ranks to -1, indicating not yet done
int rank = 0;
while (rank < (int)sz)
{
std::vector<int> els = {};
for (int i = 0; i < (int)sz; ++i)
{
if (result[i] < 0)//not yet done
{
if (!els.empty())// already found something
{
if (lt(data[i], data[els[0]]))//found a smaller item, replace existing
{
els.clear();
els.emplace_back(i);
}
else if (eq(data[i], data[els[0]]))// found a tie, add to vector
els.emplace_back(i);
}
else//els.empty==no current item, add it
els.emplace_back(i);
}
}
CV_Assert(!els.empty());
// compute, assign arithmetic mean
const auto assigned_rank = (double)rank + (double)(els.size() - 1) / 2.;
for (auto el : els)
result[el] = (float)assigned_rank;
rank += (int)els.size();
}
return result;
}
template <typename T>
double pearson(const T* x, const T* y, std::size_t sz)
{
// based on https://www.geeksforgeeks.org/program-spearmans-rank-correlation/
double sigma_x = {}, sigma_y = {}, sigma_xy = {}, sigma_xsq = {}, sigma_ysq = {};
for (unsigned i = 0; i < sz; ++i)
{
sigma_x += x[i];
sigma_y += y[i];
sigma_xy += x[i] * y[i];
sigma_xsq += x[i] * x[i];
sigma_ysq += y[i] * y[i];
}
const double
num = (sz * sigma_xy - sigma_x * sigma_y)
, den = std::sqrt(((double)sz*sigma_xsq - sigma_x * sigma_x) * ((double)sz*sigma_ysq - sigma_y * sigma_y))
;
return num / den;
}
// https://en.wikipedia.org/wiki/Spearman%27s_rank_correlation_coefficient
template <typename T>
double spearman(const T* x, const T* y, std::size_t sz)
{
// convert x, y to ranked integral vectors
const auto
x_rank = rank_ordinal(x, sz)
, y_rank = rank_ordinal(y, sz)
;
return pearson(x_rank.data(), y_rank.data(), sz);
}
// returns cv::Mat of columns: { Distortion Type ID, MOS_Score, Brisque_Score }
cv::Mat tid2008_eval(const std::string& root, cv::quality::QualityBRISQUE& alg)
{
const std::string
mos_with_names_path = root + "mos_with_names.txt"
, dist_imgs_root = root + "distorted_images/"
;
cv::Mat result(0, 3, CV_32FC1);
// distortion types we care about
static const std::vector<int> distortion_types = {
10 // jpeg compression
, 11 // jp2k compression
, 1 // additive gaussian noise
, 8 // gaussian blur
};
static const int
num_images = 25 // [I01_ - I25_], file names
, num_distortions = 4 // num distortions per image
;
// load mos_with_names. format: { mos, fname }
std::vector<std::pair<float, std::string>> mos_with_names = {};
std::ifstream mos_file(mos_with_names_path, std::ios::in);
while (true)
{
std::string line;
std::getline(mos_file, line);
if (!line.empty())
{
const auto space_pos = line.find(' ');
CV_Assert(space_pos != line.npos);
mos_with_names.emplace_back(std::make_pair(
(float)std::atof(line.substr(0, space_pos).c_str())
, line.substr(space_pos + 1)
));
}
if (mos_file.peek() == EOF)
break;
};
// foreach image
// foreach distortion type
// foreach distortion level
// distortion type id, mos value, brisque value
for (int i = 0; i < num_images; ++i)
{
for (int ty = 0; ty < (int)distortion_types.size(); ++ty)
{
for (int dist = 1; dist <= num_distortions; ++dist)
{
float mos_val = 0.f;
const std::string img_name = std::string("i")
+ (((i + 1) < 10) ? "0" : "")
+ std::to_string(i + 1)
+ "_"
+ ((distortion_types[ty] < 10) ? "0" : "")
+ std::to_string(distortion_types[ty])
+ "_"
+ std::to_string(dist)
+ ".bmp";
// find mos
bool found = false;
for (const auto& val : mos_with_names)
{
if (val.second == img_name)
{
found = true;
mos_val = val.first;
break;
}
}
CV_Assert(found);
// do brisque
auto img = cv::imread(dist_imgs_root + img_name);
// typeid, mos, brisque
cv::Mat row(1, 3, CV_32FC1);
row.at<float>(0) = (float)distortion_types[ty];
row.at<float>(1) = mos_val;
row.at<float>(2) = (float)alg.compute(img)[0];
result.push_back(row);
}// dist
}//ty
}//i
return result;
}
}
inline void printHelp()
{
using namespace std;
cout << " Demo of comparing BRISQUE quality assessment model against TID2008 database." << endl;
cout << " A. Mittal, A. K. Moorthy and A. C. Bovik, 'No Reference Image Quality Assessment in the Spatial Domain'" << std::endl << std::endl;
cout << " Usage: program <tid2008_path> <brisque_model_path> <brisque_range_path>" << endl << endl;
}
int main(int argc, const char * argv[])
{
using namespace cv::ml;
if (argc != 4)
{
printHelp();
exit(1);
}
std::cout << "Evaluating database at " << argv[1] << "..." << std::endl;
const auto ptr = cv::quality::QualityBRISQUE::create(argv[2], argv[3]);
const auto data = tid2008_eval( std::string( argv[1] ) + "/", *ptr );
// create contiguous mats
const auto mos = data.col(1).clone();
const auto brisque = data.col(2).clone();
// calc srocc
const auto cc = spearman((const float*)mos.data, (const float*)brisque.data, data.rows);
std::cout << "SROCC: " << cc << std::endl;
return 0;
}