WebSVN – seema-scanner – Diff – /src/algorithm/AlgorithmGrayCode.cpp

+//
+// Gray Code Structured Light
+//
+// This implementation closely follows Henrik Aanaes, "Lecture Notes on Computer Vision" (2014).
+//
 #include "AlgorithmGrayCode.h"
 #include <cmath>
 #include "cvtools.h"
-#ifndef log2f
-#define log2f(x) (log(x)/log(2.0))
+#include "algorithmtools.h"
-#endif
-//using namespace std;
-/*
- * The purpose of this function is to convert an unsigned
- * binary number to reflected binary Gray code.
- *
- * The operator >> is shift right. The operator ^ is exclusive or.
- * Source: http://en.wikipedia.org/wiki/Gray_code
- */
-static unsigned int binaryToGray(unsigned int num) {
-    return (num >> 1) ^ num;
-}
-/*
- * From Wikipedia: http://en.wikipedia.org/wiki/Gray_code
- * The purpose of this function is to convert a reflected binary
- * Gray code number to a binary number.
- */
-static unsigned int grayToBinary(unsigned int num){
-    unsigned int mask;
-    for(mask = num >> 1; mask != 0; mask = mask >> 1)
-        num = num ^ mask;
-    return num;
-}
-/*
- * Return the Nth bit of an unsigned integer number
- */
-static bool getBit(int decimal, int N){
-    return decimal & 1 << (N-1);
-}
-///*
-// * Return the number of bits set in an integer
-// */
-//static int countBits(int n) {
-//  unsigned int c; // c accumulates the total bits set in v
-//  for (c = 0; n>0; c++)
-//    n &= n - 1; // clear the least significant bit set
-//  return c;
-//}
-/*
- * Return the position of the least significant bit that is set
- */
-static int leastSignificantBitSet(int x){
-  if(x == 0)
-      return 0;
-  int val = 1;
-  while(x>>=1)
-      val++;
-  return val;
-}
-//static int get_bit(int decimal, int N){
-//    // Shifting the 1 for N-1 bits
-//    int constant = 1 << (N-1);
-//    // If the bit is set, return 1
-//    if( decimal & constant )
-//        return 1;
-//    else
-//        return 0;
-//}
-static inline unsigned int powi(int num, unsigned int exponent){
-    if(exponent == 0)
-        return 1;
-    float res = num;
-    for(unsigned int i=0; i<exponent-1; i++)
-        res *= num;
-    return res;
-}
-static inline unsigned int twopowi(unsigned int exponent){
-    return 1 << exponent;
-}
 // Algorithm
 AlgorithmGrayCode::AlgorithmGrayCode(unsigned int _screenCols, unsigned int _screenRows) : Algorithm(_screenCols, _screenRows){
     Nbits = ceilf(log2f((float)screenCols)) - 1;
     N = 2 + Nbits*2;
     // all on pattern
     cv::Mat allOn(1, screenCols, CV_8UC3, cv::Scalar::all(255));
     patterns.push_back(allOn);
     // all off pattern
     cv::Mat allOff(1, screenCols, CV_8UC3, cv::Scalar::all(0));
     patterns.push_back(allOff);
     // horizontally encoding patterns
     for(unsigned int p=0; p<Nbits; p++){
         cv::Mat pattern(1, screenCols, CV_8UC3);
         cv::Mat patternInv(1, screenCols, CV_8UC3);
         for(unsigned int j=0; j<screenCols; j++){
             unsigned int jGray = binaryToGray(j);
             // Amplitude of channels
             int bit = (int)getBit(jGray, Nbits-p+1);
             pattern.at<cv::Vec3b>(0,j) = cv::Vec3b(255.0*bit,255.0*bit,255.0*bit);
             int invBit = bit^1;
             patternInv.at<cv::Vec3b>(0,j) = cv::Vec3b(255.0*invBit,255.0*invBit,255.0*invBit);
+        }
         patterns.push_back(pattern);
         patterns.push_back(patternInv);
+    }
+}
 cv::Mat AlgorithmGrayCode::getEncodingPattern(unsigned int depth){
     return patterns[depth];
+}
 bool sortingLarger(cv::Vec4i i,cv::Vec4i j){ return (i[3]<j[3]);}
 bool sortingEqual(cv::Vec4i i,cv::Vec4i j){ return (i[3]==j[3]);}
 void getEdgeLabels(const cv::Mat& scanLine, int Nbits, std::vector<cv::Vec4i>& edges){
     int nCols = scanLine.cols;
     const int *data = scanLine.ptr<const int>(0);
     int labelLeft;
     int labelRight = data[0];
     // collect edges
     for(int col=1; col<nCols; col++){
         labelLeft = labelRight;
         labelRight = data[col];
         // labels need to be non-background, and differ in exactly one bit
         if(labelLeft != -1 && labelRight != -1 && (grayToBinary(labelRight) == grayToBinary(labelLeft)+1)){
             int orderingRelation = (labelLeft << Nbits) + labelRight;
             // store left label column
             edges.push_back(cv::Vec4i(col-1, labelLeft, labelRight, orderingRelation));
+        }
+    }
     // sort
     std::sort(edges.begin(), edges.end(), sortingLarger);
     // remove duplicates
     std::vector<cv::Vec4i>::iterator it;
     it = std::unique(edges.begin(), edges.end(), sortingEqual);
     edges.resize(std::distance(edges.begin(),it));
+}
-//static cv::Vec3b getColorSubpix(const cv::Mat& img, cv::Point2f pt){
-//    assert(!img.empty());
-//    assert(img.channels() == 3);
-//    int x = (int)pt.x;
-//    int y = (int)pt.y;
-//    int x0 = cv::borderInterpolate(x,   img.cols, cv::BORDER_REFLECT_101);
-//    int x1 = cv::borderInterpolate(x+1, img.cols, cv::BORDER_REFLECT_101);
-//    int y0 = cv::borderInterpolate(y,   img.rows, cv::BORDER_REFLECT_101);
-//    int y1 = cv::borderInterpolate(y+1, img.rows, cv::BORDER_REFLECT_101);
-//    float a = pt.x - (float)x;
-//    float c = pt.y - (float)y;
-//    uchar b = (uchar)cvRound((img.at<cv::Vec3b>(y0, x0)[0] * (1.f - a) + img.at<cv::Vec3b>(y0, x1)[0] * a) * (1.f - c)
-//                           + (img.at<cv::Vec3b>(y1, x0)[0] * (1.f - a) + img.at<cv::Vec3b>(y1, x1)[0] * a) * c);
-//    uchar g = (uchar)cvRound((img.at<cv::Vec3b>(y0, x0)[1] * (1.f - a) + img.at<cv::Vec3b>(y0, x1)[1] * a) * (1.f - c)
-//                           + (img.at<cv::Vec3b>(y1, x0)[1] * (1.f - a) + img.at<cv::Vec3b>(y1, x1)[1] * a) * c);
-//    uchar r = (uchar)cvRound((img.at<cv::Vec3b>(y0, x0)[2] * (1.f - a) + img.at<cv::Vec3b>(y0, x1)[2] * a) * (1.f - c)
-//                           + (img.at<cv::Vec3b>(y1, x0)[2] * (1.f - a) + img.at<cv::Vec3b>(y1, x1)[2] * a) * c);
-//    return cv::Vec3b(b, g, r);
-//}
 void AlgorithmGrayCode::get3DPoints(SMCalibrationParameters calibration, const std::vector<cv::Mat>& frames0, const std::vector<cv::Mat>& frames1, std::vector<cv::Point3f>& Q, std::vector<cv::Vec3b>& color){
     assert(frames0.size() == N);
     assert(frames1.size() == N);
 //    for(int i=0; i<1920; i++){
 //        std::cout << i << " " << binaryToGray(i) << " " << grayToBinary(binaryToGray(i)) << std::endl;
 //    }
     int frameRows = frames0[0].rows;
     int frameCols = frames0[0].cols;
     // rectifying homographies (rotation+projections)
     cv::Size frameSize(frameCols, frameRows);
     cv::Mat R, T;
     // stereoRectify segfaults unless R is double precision
     cv::Mat(calibration.R1).convertTo(R, CV_64F);
     cv::Mat(calibration.T1).convertTo(T, CV_64F);
     cv::Mat R0, R1, P0, P1, QRect;
     cv::stereoRectify(calibration.K0, calibration.k0, calibration.K1, calibration.k1, frameSize, R, T, R0, R1, P0, P1, QRect, 0);
 //    std::cout << "R0" << std::endl << R0 << std::endl;
 //    std::cout << "P0" << std::endl << P0 << std::endl;
 //    std::cout << "R1" << std::endl << R1 << std::endl;
 //    std::cout << "P1" << std::endl << P1 << std::endl;
     // interpolation maps
     cv::Mat map0X, map0Y, map1X, map1Y;
     cv::initUndistortRectifyMap(calibration.K0, calibration.k0, R0, P0, frameSize, CV_32F, map0X, map0Y);
     cv::initUndistortRectifyMap(calibration.K1, calibration.k1, R1, P1, frameSize, CV_32F, map1X, map1Y);
     // gray-scale and remap
     std::vector<cv::Mat> frames0Rect(N);
     std::vector<cv::Mat> frames1Rect(N);
     for(unsigned int i=0; i<N; i++){
         cv::Mat temp;
         cv::cvtColor(frames0[i], temp, CV_BayerBG2GRAY);
         cv::remap(temp, frames0Rect[i], map0X, map0Y, CV_INTER_LINEAR);
         cv::cvtColor(frames1[i], temp, CV_BayerBG2GRAY);
         cv::remap(temp, frames1Rect[i], map1X, map1Y, CV_INTER_LINEAR);
+    }
 //    cvtools::writeMat(frames0Rect[0], "frames0Rect_0.mat", "frames0Rect_0");
 //    cvtools::writeMat(frames0[0], "frames0_0.mat", "frames0_0");
 //    cvtools::writeMat(frames0Rect[22], "frames0Rect_22.mat", "frames0Rect_22");
 //    cvtools::writeMat(frames0Rect[23], "frames0Rect_23.mat", "frames0Rect_23");
 //    cv::imwrite("frames0[0].png", frames0[0]);
 //    cv::imwrite("frames0Rect[0].png", frames0Rect[0]);
 //    cv::imwrite("frames1[0].png", frames1[0]);
 //    cv::imwrite("frames1Rect[0].png", frames1Rect[0]);
     // color debayer and remap
     cv::Mat color0Rect, color1Rect;
 //    frames0[0].convertTo(color0Rect, CV_8UC1, 1.0/256.0);
     cv::cvtColor(frames0[0], color0Rect, CV_BayerBG2RGB);
     cv::remap(color0Rect, color0Rect, map0X, map0Y, CV_INTER_LINEAR);
 //    frames1[0].convertTo(color1Rect, CV_8UC1, 1.0/256.0);
     cv::cvtColor(frames1[0], color1Rect, CV_BayerBG2RGB);
     cv::remap(color1Rect, color1Rect, map1X, map1Y, CV_INTER_LINEAR);
     int frameRectRows = frames0Rect[0].rows;
     int frameRectCols = frames0Rect[0].cols;
 //cvtools::writeMat(frames0Rect[0], "frames0Rect_0.mat", "frames0Rect_0");
 //cvtools::writeMat(frames0Rect[1], "frames0Rect_1.mat", "frames0Rect_1");
 //cvtools::writeMat(frames0Rect[20], "frames0Rect_20.mat", "frames0Rect_20");
 //cvtools::writeMat(frames0Rect[21], "frames0Rect_21.mat", "frames0Rect_21");
     // occlusion masks
     cv::Mat occlusion0Rect, occlusion1Rect;
     cv::subtract(frames0Rect[0], frames0Rect[1], occlusion0Rect);
     occlusion0Rect = (occlusion0Rect > 10) & (occlusion0Rect < 250);
     cv::subtract(frames1Rect[0], frames1Rect[1], occlusion1Rect);
     occlusion1Rect = (occlusion1Rect > 10) & (occlusion1Rect < 250);
     // erode occlusion masks
     cv::Mat strel = cv::getStructuringElement(cv::MORPH_ELLIPSE, cv::Size(2,2));
     cv::erode(occlusion0Rect, occlusion0Rect, strel);
     cv::erode(occlusion1Rect, occlusion1Rect, strel);
 //cvtools::writeMat(frames0Rect[0], "frames0Rect_0.mat", "frames0Rect_0");
 //cvtools::writeMat(frames0Rect[1], "frames0Rect_1.mat", "frames0Rect_1");
 //cvtools::writeMat(frames0Rect[20], "frames0Rect_20.mat", "frames0Rect_20");
 //cvtools::writeMat(frames0Rect[21], "frames0Rect_21.mat", "frames0Rect_21");
 //    // correct for projector inversion error
 //    cv::Mat W;
 //    cv::add(frames0Rect[0], frames0Rect[1], W, cv::noArray(), CV_32F);
 //    for(int i=2; i<N; i+=2){
 //        cv::Mat S, E;
 //        cv::add(frames0Rect[i], frames0Rect[i+1], S, cv::noArray(), CV_32F);
 //        cv::subtract(W, S, E, cv::noArray(), CV_32F);
 //        E *= 0.5;
 //        cv::add(frames0Rect[i], E, frames0Rect[i], cv::noArray(), CV_16UC1);
 //        cv::add(frames0Rect[i+1], E, frames0Rect[i+1], cv::noArray(), CV_16UC1);
 //    }
 //    // correct for texture modulation and ambient
 //    cv::Mat A0 = frames0Rect[1];
 //    cv::Mat M0 = frames0Rect[0]-frames0Rect[1];
 ////cvtools::writeMat(A0, "A0.mat", "A0");
 ////cvtools::writeMat(M0, "M0.mat", "M0");
 ////cvtools::writeMat(frames0Rect[20], "frames0Rect_20.mat", "frames0Rect_20");
 ////cvtools::writeMat(frames0Rect[21], "frames0Rect_21.mat", "frames0Rect_21");
 //    cv::divide(256.0, M0, M0, CV_32F);
 //    cv::Mat A1 = frames1Rect[1];
 //    cv::Mat M1 = frames1Rect[0]-frames1Rect[1];
 //    cv::divide(256.0, M1, M1, CV_32F);
 //    for(int i=2; i<N; i++){
 //        cv::multiply(frames0Rect[i]-A0, M0, frames0Rect[i], 1.0, CV_8UC1);
 //        cv::multiply(frames1Rect[i]-A1, M1, frames1Rect[i], 1.0, CV_8UC1);
 //    }
 //cvtools::writeMat(frames0Rect[22], "frames0Rect_22.mat", "frames0Rect_22");
 //cvtools::writeMat(frames0Rect[23], "frames0Rect_23.mat", "frames0Rect_23");
 //cvtools::writeMat(occlusion0Rect, "occlusion0Rect.mat", "occlusion0Rect");
 //cvtools::writeMat(occlusion1Rect, "occlusion1Rect.mat", "occlusion1Rect");
     // decode patterns
     cv::Mat code0Rect(frameRectRows, frameRectCols, CV_32S, cv::Scalar(0));
     cv::Mat code1Rect(frameRectRows, frameRectCols, CV_32S, cv::Scalar(0));
     // into gray code
     for(unsigned int i=0; i<Nbits; i++){
         cv::Mat temp, bit0, bit1;
         cv::compare(frames0Rect[i*2+2], frames0Rect[i*2+3], temp, cv::CMP_GT);
         temp.convertTo(bit0, CV_32S, 1.0/255.0);
         cv::add(code0Rect, bit0*twopowi(Nbits-i-1), code0Rect, cv::noArray(), CV_32S);
         cv::compare(frames1Rect[i*2+2], frames1Rect[i*2+3], temp, cv::CMP_GT);
         temp.convertTo(bit1, CV_32S, 1.0/255.0);
         cv::add(code1Rect, bit1*twopowi(Nbits-i-1), code1Rect, cv::noArray(), CV_32S);
+    }
 //cvtools::writeMat(code0Rect, "code0Rect.mat", "code0Rect");
 //cvtools::writeMat(code1Rect, "code1Rect.mat", "code1Rect");
 //    // convert to standard binary
 //    cv::Mat code0Binary(code0Rect.rows, code0Rect.cols, CV_32F);
 //    cv::Mat code1Binary(code1Rect.rows, code1Rect.cols, CV_32F);
 //    for(int r=0; r<frameRectRows; r++){
 //        for(int c=0; c<frameRectCols; c++){
 //            if(code0Rect.at<int>(r,c) != -1)
 //                code0Binary.at<float>(r,c) = grayToBinary(code0Rect.at<int>(r,c));
 //            if(code1Rect.at<int>(r,c) != -1)
 //                code1Binary.at<float>(r,c) = grayToBinary(code1Rect.at<int>(r,c));
 //        }
 //    }
 //cvtools::writeMat(code0Binary, "code0Binary.mat", "code0Binary");
 //cvtools::writeMat(code1Binary, "code1Binary.mat", "code1Binary");
 //    // threshold on vertical discontinuities (due to imperfect rectification)
 //    cv::Mat edges0;
 //    cv::Sobel(code0Binary, edges0, -1, 0, 1, 5);
 //    occlusion0Rect = occlusion0Rect & (abs(edges0) < 50);
 //    cv::Mat edges1;
 //    cv::Sobel(code1Binary, edges1, -1, 0, 1, 5);
 //    occlusion1Rect = occlusion1Rect & (abs(edges1) < 50);
 //cvtools::writeMat(edges0, "edges0.mat", "edges0");
 //cvtools::writeMat(edges1, "edges1.mat", "edges1");
     // set occluded pixels to -1
     for(int r=0; r<frameRectRows; r++){
         for(int c=0; c<frameRectCols; c++){
             if(occlusion0Rect.at<unsigned char>(r,c) == 0)
                 code0Rect.at<int>(r,c) = -1;
             if(occlusion1Rect.at<unsigned char>(r,c) == 0)
                 code1Rect.at<int>(r,c) = -1;
+        }
+    }
 //    cvtools::writeMat(code0Rect, "code0Rect.mat", "code0Rect");
 //    cvtools::writeMat(code1Rect, "code1Rect.mat", "code1Rect");
     // matching
     std::vector<cv::Vec2f> q0Rect, q1Rect;
     for(int row=0; row<frameRectRows; row++){
         // edge data structure containing [floor(column), labelLeft, labelRight, orderingRelation]
         std::vector<cv::Vec4i> edges0, edges1;
         // sorted, unique edges
         getEdgeLabels(code0Rect.row(row), Nbits, edges0);
         getEdgeLabels(code1Rect.row(row), Nbits, edges1);
         // match edges
         std::vector<cv::Vec4i> matchedEdges0, matchedEdges1;
         unsigned int i=0, j=0;
         while(i<edges0.size() && j<edges1.size()){
             if(edges0[i][3] == edges1[j][3]){
                 matchedEdges0.push_back(edges0[i]);
                 matchedEdges1.push_back(edges1[j]);
                 i += 1;
                 j += 1;
             } else if(edges0[i][3] < edges1[j][3]){
                 i += 1;
             } else if(edges0[i][3] > edges1[j][3]){
                 j += 1;
+            }
+        }
         // crude subpixel refinement
         // finds the intersection of linear interpolants in the positive/negative pattern
         for(unsigned int i=0; i<matchedEdges0.size(); i++){
             int level = Nbits - leastSignificantBitSet(matchedEdges0[i][1]^matchedEdges0[i][2]);
             // refine for camera 0
             float c0 = matchedEdges0[i][0];
             float c1 = c0+1;
             float pos0 = frames0Rect[2*level+2].at<unsigned char>(row, c0);
             float pos1 = frames0Rect[2*level+2].at<unsigned char>(row, c1);
             float neg0 = frames0Rect[2*level+3].at<unsigned char>(row, c0);
             float neg1 = frames0Rect[2*level+3].at<unsigned char>(row, c1);
             float col = c0 + (pos0 - neg0)/(neg1 - neg0 - pos1 + pos0);
             q0Rect.push_back(cv::Point2f(col, row));
             // refine for camera 1
             c0 = matchedEdges1[i][0];
             c1 = c0+1;
             pos0 = frames1Rect[2*level+2].at<unsigned char>(row, c0);
             pos1 = frames1Rect[2*level+2].at<unsigned char>(row, c1);
             neg0 = frames1Rect[2*level+3].at<unsigned char>(row, c0);
             neg1 = frames1Rect[2*level+3].at<unsigned char>(row, c1);
             col = c0 + (pos0 - neg0)/(neg1 - neg0 - pos1 + pos0);
             q1Rect.push_back(cv::Point2f(col, row));
+        }
+    }
     int nMatches = q0Rect.size();
     if(nMatches < 1){
         Q.resize(0);
         color.resize(0);
         return;
+    }
     // retrieve color information (at integer coordinates)
     color.resize(nMatches);
     for(int i=0; i<nMatches; i++){
         cv::Vec3b c0 = color0Rect.at<cv::Vec3b>(q0Rect[i][1], q0Rect[i][0]);
         cv::Vec3b c1 = color1Rect.at<cv::Vec3b>(q1Rect[i][1], q1Rect[i][0]);
-//        cv::Vec3b c0 = getColorSubpix(color0Rect, q0Rect[i]);
-//        cv::Vec3b c1 = getColorSubpix(color1Rect, q0Rect[i]);
         color[i] = 0.5*c0 + 0.5*c1;
+    }
     // triangulate points
     cv::Mat QMatHomogenous, QMat;
 //    cv::Mat C0 = P0.clone();
 //    cv::Mat C1 = P1.clone();
 //    C0.colRange(0, 3) = C0.colRange(0, 3)*R0;
 //    C1.colRange(0, 3) = C1.colRange(0, 3)*R1.t();
     cv::triangulatePoints(P0, P1, q0Rect, q1Rect, QMatHomogenous);
     cvtools::convertMatFromHomogeneous(QMatHomogenous, QMat);
     // undo rectifying rotation
     cv::Mat R0Inv;
     cv::Mat(R0.t()).convertTo(R0Inv, CV_32F);
     QMat = R0Inv*QMat;
     cvtools::matToPoints3f(QMat, Q);
+}

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(root)/src/algorithm/AlgorithmGrayCode.cpp – Rev 167 → 182