|
| 1 | +// |
| 2 | +// Created by Jack Yu on 23/03/2018. |
| 3 | +// |
| 4 | + |
| 5 | +#ifndef FACE_DEMO_FACEPREPROCESS_H |
| 6 | +#define FACE_DEMO_FACEPREPROCESS_H |
| 7 | + |
| 8 | +#include<opencv2/opencv.hpp> |
| 9 | + |
| 10 | + |
| 11 | +namespace FacePreprocess { |
| 12 | + |
| 13 | + cv::Mat meanAxis0(const cv::Mat &src) |
| 14 | + { |
| 15 | + int num = src.rows; |
| 16 | + int dim = src.cols; |
| 17 | + |
| 18 | + // x1 y1 |
| 19 | + // x2 y2 |
| 20 | + |
| 21 | + cv::Mat output(1,dim,CV_32F); |
| 22 | + for(int i = 0 ; i < dim; i ++) |
| 23 | + { |
| 24 | + float sum = 0 ; |
| 25 | + for(int j = 0 ; j < num ; j++) |
| 26 | + { |
| 27 | + sum+=src.at<float>(j,i); |
| 28 | + } |
| 29 | + output.at<float>(0,i) = sum/num; |
| 30 | + } |
| 31 | + |
| 32 | + return output; |
| 33 | + } |
| 34 | + |
| 35 | + cv::Mat elementwiseMinus(const cv::Mat &A,const cv::Mat &B) |
| 36 | + { |
| 37 | + cv::Mat output(A.rows,A.cols,A.type()); |
| 38 | + |
| 39 | + assert(B.cols == A.cols); |
| 40 | + if(B.cols == A.cols) |
| 41 | + { |
| 42 | + for(int i = 0 ; i < A.rows; i ++) |
| 43 | + { |
| 44 | + for(int j = 0 ; j < B.cols; j++) |
| 45 | + { |
| 46 | + output.at<float>(i,j) = A.at<float>(i,j) - B.at<float>(0,j); |
| 47 | + } |
| 48 | + } |
| 49 | + } |
| 50 | + return output; |
| 51 | + } |
| 52 | + |
| 53 | + |
| 54 | + cv::Mat varAxis0(const cv::Mat &src) |
| 55 | + { |
| 56 | + cv:Mat temp_ = elementwiseMinus(src,meanAxis0(src)); |
| 57 | + cv::multiply(temp_ ,temp_ ,temp_ ); |
| 58 | + return meanAxis0(temp_); |
| 59 | + |
| 60 | + } |
| 61 | + |
| 62 | + |
| 63 | + |
| 64 | + int MatrixRank(cv::Mat M) |
| 65 | + { |
| 66 | + Mat w, u, vt; |
| 67 | + SVD::compute(M, w, u, vt); |
| 68 | + Mat1b nonZeroSingularValues = w > 0.0001; |
| 69 | + int rank = countNonZero(nonZeroSingularValues); |
| 70 | + return rank; |
| 71 | + |
| 72 | + } |
| 73 | + |
| 74 | +// References |
| 75 | +// ---------- |
| 76 | +// .. [1] "Least-squares estimation of transformation parameters between two |
| 77 | +// point patterns", Shinji Umeyama, PAMI 1991, DOI: 10.1109/34.88573 |
| 78 | +// |
| 79 | +// """ |
| 80 | +// |
| 81 | +// Anthor:Jack Yu |
| 82 | + cv::Mat similarTransform(cv::Mat src,cv::Mat dst) { |
| 83 | + int num = src.rows; |
| 84 | + int dim = src.cols; |
| 85 | + cv::Mat src_mean = meanAxis0(src); |
| 86 | + cv::Mat dst_mean = meanAxis0(dst); |
| 87 | + cv::Mat src_demean = elementwiseMinus(src, src_mean); |
| 88 | + cv::Mat dst_demean = elementwiseMinus(dst, dst_mean); |
| 89 | + cv::Mat A = (dst_demean.t() * src_demean) / static_cast<float>(num); |
| 90 | + cv::Mat d(dim, 1, CV_32F); |
| 91 | + d.setTo(1.0f); |
| 92 | + if (cv::determinant(A) < 0) { |
| 93 | + d.at<float>(dim - 1, 0) = -1; |
| 94 | + |
| 95 | + } |
| 96 | + Mat T = cv::Mat::eye(dim + 1, dim + 1, CV_32F); |
| 97 | + cv::Mat U, S, V; |
| 98 | + SVD::compute(A, S,U, V); |
| 99 | + |
| 100 | + // the SVD function in opencv differ from scipy . |
| 101 | + |
| 102 | + |
| 103 | + int rank = MatrixRank(A); |
| 104 | + if (rank == 0) { |
| 105 | + assert(rank == 0); |
| 106 | + |
| 107 | + } else if (rank == dim - 1) { |
| 108 | + if (cv::determinant(U) * cv::determinant(V) > 0) { |
| 109 | + T.rowRange(0, dim).colRange(0, dim) = U * V; |
| 110 | + } else { |
| 111 | +// s = d[dim - 1] |
| 112 | +// d[dim - 1] = -1 |
| 113 | +// T[:dim, :dim] = np.dot(U, np.dot(np.diag(d), V)) |
| 114 | +// d[dim - 1] = s |
| 115 | + int s = d.at<float>(dim - 1, 0) = -1; |
| 116 | + d.at<float>(dim - 1, 0) = -1; |
| 117 | + |
| 118 | + T.rowRange(0, dim).colRange(0, dim) = U * V; |
| 119 | + cv::Mat diag_ = cv::Mat::diag(d); |
| 120 | + cv::Mat twp = diag_*V; //np.dot(np.diag(d), V.T) |
| 121 | + Mat B = Mat::zeros(3, 3, CV_8UC1); |
| 122 | + Mat C = B.diag(0); |
| 123 | + T.rowRange(0, dim).colRange(0, dim) = U* twp; |
| 124 | + d.at<float>(dim - 1, 0) = s; |
| 125 | + } |
| 126 | + } |
| 127 | + else{ |
| 128 | + cv::Mat diag_ = cv::Mat::diag(d); |
| 129 | + cv::Mat twp = diag_*V.t(); //np.dot(np.diag(d), V.T) |
| 130 | + cv::Mat res = U* twp; // U |
| 131 | + T.rowRange(0, dim).colRange(0, dim) = -U.t()* twp; |
| 132 | + } |
| 133 | + cv::Mat var_ = varAxis0(src_demean); |
| 134 | + float val = cv::sum(var_).val[0]; |
| 135 | + cv::Mat res; |
| 136 | + cv::multiply(d,S,res); |
| 137 | + float scale = 1.0/val*cv::sum(res).val[0]; |
| 138 | + T.rowRange(0, dim).colRange(0, dim) = - T.rowRange(0, dim).colRange(0, dim).t(); |
| 139 | + cv::Mat temp1 = T.rowRange(0, dim).colRange(0, dim); // T[:dim, :dim] |
| 140 | + cv::Mat temp2 = src_mean.t(); //src_mean.T |
| 141 | + cv::Mat temp3 = temp1*temp2; // np.dot(T[:dim, :dim], src_mean.T) |
| 142 | + cv::Mat temp4 = scale*temp3; |
| 143 | + T.rowRange(0, dim).colRange(dim, dim+1)= -(temp4 - dst_mean.t()) ; |
| 144 | + T.rowRange(0, dim).colRange(0, dim) *= scale; |
| 145 | + return T; |
| 146 | + } |
| 147 | + |
| 148 | + |
| 149 | +} |
| 150 | +#endif //FACE_DEMO_FACEPREPROCESS_H |
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