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

 #include "AlgorithmGrayCode.h"
 #include <cmath>
 #include "cvtools.h"
 #ifndef log2f
 #define log2f(x) (log(x)/log(2.0))
 #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, CodingDir _dir) : Algorithm(_screenCols, _screenRows, _dir){
     // on/off patterns
     Nbits = ceilf(log2f((float)screenCols));
     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);
             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::Vec4f i,cv::Vec4f j){ return (i[3]<j[3]);}
+bool sortingLarger(cv::Vec4i i,cv::Vec4i j){ return (i[3]<j[3]);}
-bool sortingEqual(cv::Vec4f i,cv::Vec4f 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::Vec4f>& edges){
+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 non-background, and differ in exactly one bit
-        if(labelLeft != -1 && labelRight != -1 && labelLeft != labelRight){
+        if(labelLeft != -1 && labelRight != -1 && countBits(labelLeft^labelRight) == 1){
             int orderingRelation = (labelLeft << Nbits) + labelRight;
+            // store left label column
-            edges.push_back(cv::Vec4f(col-0.5, labelLeft, labelRight, orderingRelation));
+            edges.push_back(cv::Vec4i(col-1, labelLeft, labelRight, orderingRelation));
+        }
+    }
     // sort
     std::sort(edges.begin(), edges.end(), sortingLarger);
     // remove duplicates
-    std::vector<cv::Vec4f>::iterator it;
+    std::vector<cv::Vec4i>::iterator it;
     it = std::unique(edges.begin(), edges.end(), sortingEqual);
     edges.resize(std::distance(edges.begin(),it));
+}
 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++){
+//    for(int i=0; i<1920; i++){
-        std::cout << i << " " << binaryToGray(i) << " " << grayToBinary(binaryToGray(i)) << std::endl;
+//        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 << "R0" << std::endl << R0 << std::endl;
-    std::cout << "P0" << std::endl << P0 << std::endl;
+//    std::cout << "P0" << std::endl << P0 << std::endl;
-    std::cout << "R1" << std::endl << R1 << std::endl;
+//    std::cout << "R1" << std::endl << R1 << std::endl;
-    std::cout << "P1" << std::endl << P1 << 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(int i=0; i<N; i++){
         cv::Mat temp;
         cv::cvtColor(frames0[i], temp, CV_RGB2GRAY);
-        cv::remap(temp, frames0Rect[i], map0X, map0Y, CV_INTER_LINEAR);
+        cv::remap(temp, frames0Rect[i], map0X, map0Y, CV_INTER_CUBIC);
         cv::cvtColor(frames1[i], temp, CV_RGB2GRAY);
-        cv::remap(temp, frames1Rect[i], map1X, map1Y, CV_INTER_LINEAR);
+        cv::remap(temp, frames1Rect[i], map1X, map1Y, CV_INTER_CUBIC);
+    }
+//    cv::imwrite("frames0Rect[N-1].png", frames0Rect[N-1]);
     // color remaps
     cv::Mat color0Rect, color1Rect;
     cv::remap(frames0[0], color0Rect, map0X, map0Y, CV_INTER_CUBIC);
     cv::remap(frames1[0], color1Rect, map1X, map1Y, CV_INTER_CUBIC);
     int frameRectRows = frames0Rect[0].rows;
     int frameRectCols = frames0Rect[0].cols;
-    // occlusion maps
+    // occlusion masks
     cv::Mat occlusion0Rect, occlusion1Rect;
     cv::subtract(frames0Rect[0], frames0Rect[1], occlusion0Rect);
     occlusion0Rect = occlusion0Rect > 50;
     cv::subtract(frames1Rect[0], frames1Rect[1], occlusion1Rect);
     occlusion1Rect = occlusion1Rect > 50;
+    // erode occlusion masks
+    cv::Mat strel = cv::getStructuringElement(cv::MORPH_ELLIPSE, cv::Size(3,3));
+    cv::erode(occlusion0Rect, occlusion0Rect, strel);
+    cv::erode(occlusion1Rect, occlusion1Rect, strel);
 //cvtools::writeMat(occlusion0Rect, "occlusion0Rect.mat", "occlusion0Rect");
 //cvtools::writeMat(occlusion1Rect, "occlusion1Rect.mat", "occlusion1Rect");
     // decode patterns
     cv::Mat code0Rect(frameRectRows, frameRectCols, CV_32S, cv::Scalar(-1));
     cv::Mat code1Rect(frameRectRows, frameRectCols, CV_32S, cv::Scalar(-1));
     cv::add(code0Rect, 1, code0Rect, occlusion0Rect, CV_32S);
     cv::add(code1Rect, 1, code1Rect, occlusion1Rect, CV_32S);
     // into gray code
     for(int i=0; i<Nbits; i++){
         cv::Mat bit0;
         cv::subtract(frames0Rect[i*2+2], frames0Rect[i*2+3], bit0);
         bit0 = bit0 > 0;
         bit0.convertTo(bit0, CV_32S, 1.0/255.0);
 //      cvtools::writeMat(bit0, "bit0.mat", "bit0");
         cv::add(code0Rect, bit0*twopowi(Nbits-i-1), code0Rect, occlusion0Rect, CV_32S);
         cv::Mat bit1;
         cv::subtract(frames1Rect[i*2+2], frames1Rect[i*2+3], bit1);
         bit1 = bit1 > 0;
         bit1.convertTo(bit1, CV_32S, 1.0/255.0);
         cv::add(code1Rect, bit1*twopowi(Nbits-i-1), code1Rect, occlusion1Rect, CV_32S);
+    }
 //cvtools::writeMat(code0Rect, "code0Rect.mat", "code0Rect");
 //cvtools::writeMat(code1Rect, "code1Rect.mat", "code1Rect");
 //    // convert to standard binary
 //    for(int r=0; r<frameRectRows; r++){
 //        for(int c=0; c<frameRectCols; c++){
 //            if(code0Rect.at<int>(r,c) != -1)
 //                code0Rect.at<int>(r,c) = grayToBinary(code0Rect.at<int>(r,c));
 //            if(code1Rect.at<int>(r,c) != -1)
 //                code1Rect.at<int>(r,c) = grayToBinary(code1Rect.at<int>(r,c));
 //        }
 //    }
 //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++){
-        std::vector<cv::Vec4f> edges0, edges1;
+        std::vector<cv::Vec4i> edges0, edges1;
         // sorted, unique edges
         getEdgeLabels(code0Rect.row(row), Nbits, edges0);
         getEdgeLabels(code1Rect.row(row), Nbits, edges1);
-        // subpixel refinement
+        // match edges
-        // ...
+        std::vector<cv::Vec4i> matchedEdges0, matchedEdges1;
         int i=0, j=0;
         while(i<edges0.size() && j<edges1.size()){
             if(edges0[i][3] == edges1[j][3]){
-                q0Rect.push_back(cv::Vec2f(edges0[i][0], row));
+                matchedEdges0.push_back(edges0[i]);
-                q1Rect.push_back(cv::Vec2f(edges1[j][0], row));
+                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(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<char>(row, c0);
+            float pos1 = frames0Rect[2*level+2].at<char>(row, c1);
+            float neg0 = frames0Rect[2*level+3].at<char>(row, c0);
+            float neg1 = frames0Rect[2*level+3].at<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<char>(row, c0);
+            pos1 = frames1Rect[2*level+2].at<char>(row, c1);
+            neg0 = frames1Rect[2*level+3].at<char>(row, c0);
+            neg1 = frames1Rect[2*level+3].at<char>(row, c1);
+            col = c0 + (pos0 - neg0)/(neg1 - neg0 - pos1 + pos0);
+            q1Rect.push_back(cv::Point2f(col, row));
+        }
+    }
     // retrieve color information
     int nMatches = q0Rect.size();
     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]);
         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 rectification
     cv::Mat R0Inv;
     cv::Mat(R0.t()).convertTo(R0Inv, CV_32F);
     QMat = R0Inv*QMat;
     cvtools::matToPoints3f(QMat, Q);
+}

Subversion Repositories seema-scanner

(root)/src/algorithm/AlgorithmGrayCode.cpp – Rev 45 → 47