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

-#include "AlgorithmGrayCode.h"
+#include "AlgorithmLineShift.h"
 #include <cmath>
 #include "cvtools.h"
+#include <opencv2/imgproc.hpp>
 #ifndef log2f
 #define log2f(x) (log(x)/log(2.0))
 #endif
-//using namespace std;
+static unsigned int nLineShifts = 8; // number of columns over which each line is shifted
 /*
  * The purpose of this function is to convert an unsigned
  * binary number to reflected binary Gray code.
+ *
       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;
     return 1 << exponent;
+}
 // Algorithm
-AlgorithmGrayCode::AlgorithmGrayCode(unsigned int _screenCols, unsigned int _screenRows) : Algorithm(_screenCols, _screenRows){
+AlgorithmLineShift::AlgorithmLineShift(unsigned int _screenCols, unsigned int _screenRows) : Algorithm(_screenCols, _screenRows){
+    nGrayBits = ceilf(log2f((float)screenCols)) - floorf(log2f((float)nLineShifts));
-    Nbits = ceilf(log2f((float)screenCols));
-    N = 2 + Nbits*2;
+    N = 2 + 2*nGrayBits + nLineShifts;
     // 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
+    // Gray code patterns
-    for(unsigned int p=0; p<Nbits; p++){
+    for(unsigned int p=0; p<nGrayBits; 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);
+            int bit = (int)getBit(jGray, nGrayBits-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);
+    }
+    // line shifts
+    for(unsigned int p=0; p<nLineShifts; p++){
+        cv::Mat pattern(1, screenCols, CV_8UC3, cv::Vec3b(0, 0, 0));
-}
+        for(unsigned int j=p; j<screenCols; j+= nLineShifts)
+            pattern.at<cv::Vec3b>(0, j) = cv::Vec3b(255, 255, 255);
-cv::Mat AlgorithmGrayCode::getEncodingPattern(unsigned int depth){
-    return patterns[depth];
+        patterns.push_back(pattern);
+    }
-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);
+cv::Mat AlgorithmLineShift::getEncodingPattern(unsigned int depth){
-    // remove duplicates
+    return patterns[depth];
-    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);
                            + (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 getlineCenters(const cv::Mat& linesScanLine, const cv::Mat& codeScanLine, std::vector<cv::Vec4i>& lineCenters){
+    int nCols = linesScanLine.cols;
+    // fourth order derivative filtering
+    cv::Mat der(1, nCols, CV_8U);
+    for(int i=2; i<nCols-2; i++)
+        der.at<unsigned char>(0, i) = linesScanLine.at<unsigned char>(0, i-2)+linesScanLine.at<unsigned char>(0, i-1)-
+                                      linesScanLine.at<unsigned char>(0, i+1)-linesScanLine.at<unsigned char>(0, i+2);
+    for(int i=0; i<nCols; i++){
+        if(der.at<unsigned char>(0, i) > 0 && der.at<unsigned char>(0, i+1) < 0){
+            lineCenters.push_back(i, codeScanLine.at<unsigned char>(0, i));
+            // TODO: subpixel interpolation, non-max suppression
+        }
+    }
+}
-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){
+void AlgorithmLineShift::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(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);
         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(frames0Rect[0], "frames0Rect_0.mat", "frames0Rect_0");
-//    cvtools::writeMat(frames0[0], "frames0_0.mat", "frames0_0");
+    //cvtools::writeMat(frames0Rect[1], "frames0Rect_1.mat", "frames0Rect_1");
-//    cvtools::writeMat(frames0Rect[22], "frames0Rect_22.mat", "frames0Rect_22");
+    //cvtools::writeMat(frames0Rect[20], "frames0Rect_20.mat", "frames0Rect_20");
-//    cvtools::writeMat(frames0Rect[23], "frames0Rect_23.mat", "frames0Rect_23");
+    //cvtools::writeMat(frames0Rect[21], "frames0Rect_21.mat", "frames0Rect_21");
-//    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 > 20) & (occlusion0Rect < 250);
     cv::subtract(frames1Rect[0], frames1Rect[1], occlusion1Rect);
     occlusion1Rect = (occlusion1Rect > 20) & (occlusion1Rect < 250);
+    //cvtools::writeMat(occlusion0Rect, "occlusion0Rect.mat", "occlusion0Rect");
+    //cvtools::writeMat(occlusion1Rect, "occlusion1Rect.mat", "occlusion1Rect");
     // 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);
+    }
-//cvtools::writeMat(frames0Rect[22], "frames0Rect_22.mat", "frames0Rect_22");
+    //cvtools::writeMat(frames0Rect[22], "frames0Rect_22.mat", "frames0Rect_22");
-//cvtools::writeMat(frames0Rect[23], "frames0Rect_23.mat", "frames0Rect_23");
+    //cvtools::writeMat(frames0Rect[23], "frames0Rect_23.mat", "frames0Rect_23");
+    // divide into Gray coding frames and line shift frames
+    std::vector<cv::Mat> frames0GrayCode(frames0Rect.begin()+2, frames0Rect.begin()+2+nGrayBits);
-//cvtools::writeMat(occlusion0Rect, "occlusion0Rect.mat", "occlusion0Rect");
+    std::vector<cv::Mat> frames0LineShift(frames0Rect.begin()+2+nGrayBits, frames0Rect.end());
+    std::vector<cv::Mat> frames1GrayCode(frames1Rect.begin()+2, frames1Rect.begin()+2+nGrayBits);
-//cvtools::writeMat(occlusion1Rect, "occlusion1Rect.mat", "occlusion1Rect");
+    std::vector<cv::Mat> frames1LineShift(frames1Rect.begin()+2+nGrayBits, frames1Rect.end());
     // decode patterns
-    cv::Mat code0Rect(frameRectRows, frameRectCols, CV_32S, cv::Scalar(0));
+    cv::Mat code0Gray(frameRectRows, frameRectCols, CV_32S, cv::Scalar(0));
-    cv::Mat code1Rect(frameRectRows, frameRectCols, CV_32S, cv::Scalar(0));
+    cv::Mat code1Gray(frameRectRows, frameRectCols, CV_32S, cv::Scalar(0));
     // into gray code
-    for(int i=0; i<Nbits; i++){
+    for(int i=0; i<nGrayBits; i++){
         cv::Mat temp, bit0, bit1;
-        cv::compare(frames0Rect[i*2+2], frames0Rect[i*2+3], temp, cv::CMP_GT);
+        cv::compare(frames0GrayCode[i*2], frames0GrayCode[i*2+1], 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::add(code0Gray, bit0*twopowi(Nbits-i-1), code0Gray, cv::noArray(), CV_32S);
-        cv::compare(frames1Rect[i*2+2], frames1Rect[i*2+3], temp, cv::CMP_GT);
+        cv::compare(frames1GrayCode[i*2], frames1GrayCode[i*2+1], 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);
+        cv::add(code1Gray, bit1*twopowi(Nbits-i-1), code1Gray, 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;
+                code0Gray.at<int>(r,c) = -1;
             if(occlusion1Rect.at<unsigned char>(r,c) == 0)
-                code1Rect.at<int>(r,c) = -1;
+                code1Gray.at<int>(r,c) = -1;
+        }
+    }
+    // convert to standard binary
+    cv::Mat code0Binary(code0Gray.rows, code0Gray.cols, CV_32F);
+    cv::Mat code1Binary(code1Gray.rows, code1Gray.cols, CV_32F);
+    for(int r=0; r<frameRectRows; r++){
+        for(int c=0; c<frameRectCols; c++){
+            if(code0Gray.at<int>(r,c) != -1)
+                code0Binary.at<float>(r,c) = grayToBinary(code0Gray.at<int>(r,c));
+            if(code1Gray.at<int>(r,c) != -1)
+                code1Binary.at<float>(r,c) = grayToBinary(code1Gray.at<int>(r,c));
+        }
+    }
-//    cvtools::writeMat(code0Rect, "code0Rect.mat", "code0Rect");
+    //cvtools::writeMat(code0Gray, "code0Gray.mat", "code0Gray");
-//    cvtools::writeMat(code1Rect, "code1Rect.mat", "code1Rect");
+    //cvtools::writeMat(code1Gray, "code1Gray.mat", "code1Gray");
+    // TODO: iterate through all line frames
+    cv::Mat lines0 = frames0LineShift[0];
+    cv::Mat lines1 = frames1LineShift[0];
     // matching
     std::vector<cv::Vec2f> q0Rect, q1Rect;
     for(int row=0; row<frameRectRows; row++){
-        // edge data structure containing [floor(column), labelLeft, labelRight, orderingRelation]
+        // line center data structure containing [x-coordinate (sub-px), region-code]
-        std::vector<cv::Vec4i> edges0, edges1;
+        std::vector<cv::Vec2f> lineCenters0, lineCenters1;
-        // sorted, unique edges
+        // sorted, unique line centers
-        getEdgeLabels(code0Rect.row(row), Nbits, edges0);
+        getlineCenters(lines0.row(row), code0Binary.row(row), lineCenters0);
-        getEdgeLabels(code1Rect.row(row), Nbits, edges1);
+        getlineCenters(lines1.row(row), code1Binary.row(row), lineCenters1);
-        // match edges
+        // match and store
-        std::vector<cv::Vec4i> matchedEdges0, matchedEdges1;
         int i=0, j=0;
-        while(i<edges0.size() && j<edges1.size()){
+        while(i<lineCenters0.size() && j<lineCenters1.size()){
-            if(edges0[i][3] == edges1[j][3]){
+            if(lineCenters0[i][1] == lineCenters1[j][1]){
-                matchedEdges0.push_back(edges0[i]);
+                q0Rect.push_back(cv::Point2f(lineCenters0[0][0], row));
-                matchedEdges1.push_back(edges1[j]);
+                q1Rect.push_back(cv::Point2f(lineCenters1[0][0], row));
                 i += 1;
                 j += 1;
-            } else if(edges0[i][3] < edges1[j][3]){
+            } else if(lineCenters0[i][1] < lineCenters1[j][1]){
                 i += 1;
-            } else if(edges0[i][3] > edges1[j][3]){
+            } else if(lineCenters0[i][1] > lineCenters1[j][1]){
                 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<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){
         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;

Subversion Repositories seema-scanner

(root)/src/algorithm/AlgorithmLineShift.cpp – Rev 122 → 123