人臉姿態估計

由於需要在採集的集中選擇與待識別人臉姿態最接近的與之進行對比，因此考慮使用人臉姿態估計計算人臉在三維空間的角度，然後找出與之最接近的角度。

在網上查閱資料發現大多都是演算法介紹，缺少原始碼，最終在github上找到乙個基於dlib68點檢測和opencv計算角度的專案<< head-pose-estimation>>，感謝lincolnhard。

在此貼出計算一張人臉姿態的**。

facepose_estimation.cpp：

#include 

#include 
#include 
#include 
#include 
#include 
using
namespace dlib;
using
namespace
std;
//intrisics can be calculated using opencv sample code under opencv/sources/samples/cpp/tutorial_code/calib3d
double k[9] = ;
double d[5] = ;
int main()
//fill in 2d ref points, annotations follow 
image_pts.push_back(cv::point2d(shape.part(17).x(), shape.part(17).y())); //#17 left brow left corner
image_pts.push_back(cv::point2d(shape.part(21).x(), shape.part(21).y())); //#21 left brow right corner
image_pts.push_back(cv::point2d(shape.part(22).x(), shape.part(22).y())); //#22 right brow left corner
image_pts.push_back(cv::point2d(shape.part(26).x(), shape.part(26).y())); //#26 right brow right corner
image_pts.push_back(cv::point2d(shape.part(36).x(), shape.part(36).y())); //#36 left eye left corner
image_pts.push_back(cv::point2d(shape.part(39).x(), shape.part(39).y())); //#39 left eye right corner
image_pts.push_back(cv::point2d(shape.part(42).x(), shape.part(42).y())); //#42 right eye left corner
image_pts.push_back(cv::point2d(shape.part(45).x(), shape.part(45).y())); //#45 right eye right corner
image_pts.push_back(cv::point2d(shape.part(31).x(), shape.part(31).y())); //#31 nose left corner
image_pts.push_back(cv::point2d(shape.part(35).x(), shape.part(35).y())); //#35 nose right corner
image_pts.push_back(cv::point2d(shape.part(48).x(), shape.part(48).y())); //#48 mouth left corner
image_pts.push_back(cv::point2d(shape.part(54).x(), shape.part(54).y())); //#54 mouth right corner
image_pts.push_back(cv::point2d(shape.part(57).x(), shape.part(57).y())); //#57 mouth central bottom corner
image_pts.push_back(cv::point2d(shape.part(8).x(), shape.part(8).y())); //#8 chin corner
//calc pose
cv::solvepnp(object_pts, image_pts, cam_matrix, dist_coeffs, rotation_vec, translation_vec);
//reproject
cv::projectpoints(reprojectsrc, rotation_vec, translation_vec, cam_matrix, dist_coeffs, reprojectdst);
//draw axis
line(temp, reprojectdst[0], reprojectdst[1], cv::scalar(0, 0, 255));
line(temp, reprojectdst[1], reprojectdst[2], cv::scalar(0, 0, 255));
line(temp, reprojectdst[2], reprojectdst[3], cv::scalar(0, 0, 255));
line(temp, reprojectdst[3], reprojectdst[0], cv::scalar(0, 0, 255));
line(temp, reprojectdst[4], reprojectdst[5], cv::scalar(0, 0, 255));
line(temp, reprojectdst[5], reprojectdst[6], cv::scalar(0, 0, 255));
line(temp, reprojectdst[6], reprojectdst[7], cv::scalar(0, 0, 255));
line(temp, reprojectdst[7], reprojectdst[4], cv::scalar(0, 0, 255));
line(temp, reprojectdst[0], reprojectdst[4], cv::scalar(0, 0, 255));
line(temp, reprojectdst[1], reprojectdst[5], cv::scalar(0, 0, 255));
line(temp, reprojectdst[2], reprojectdst[6], cv::scalar(0, 0, 255));
line(temp, reprojectdst[3], reprojectdst[7], cv::scalar(0, 0, 255));
//calc euler angle
cv::rodrigues(rotation_vec, rotation_mat);
cv::hconcat(rotation_mat, translation_vec, pose_mat);
cv::decomposeprojectionmatrix(pose_mat, out_intrinsics, out_rotation, out_translation, cv::noarray(), cv::noarray(), cv::noarray(), euler_angle);
//show angle result 
outtext << "x: "
<< setprecision(3) << euler_angle.at(0);
cv::puttext(temp, outtext.str(), cv::point(50, 40), cv::font_hershey_******x, 0.75, cv::scalar(0, 255, 0));
outtext.str("");
outtext << "y: "
<< setprecision(3) << euler_angle.at(1);
cv::puttext(temp, outtext.str(), cv::point(50, 60), cv::font_hershey_******x, 0.75, cv::scalar(0, 255, 0));
outtext.str("");
outtext << "z: "
<< setprecision(3) << euler_angle.at(2);
cv::puttext(temp, outtext.str(), cv::point(50, 80), cv::font_hershey_******x, 0.75, cv::scalar(0, 255, 0));
outtext.str("");
image_pts.clear();
}imshow("demo", temp);
cvwaitkey(0);
return
0;}

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