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"
#include "algorithmtools.h"
 
// Algorithm
AlgorithmGrayCode::AlgorithmGrayCode(unsigned int _screenCols, unsigned int _screenRows) : Algorithm(_screenCols, _screenRows){
 
    Nbits = 6;
    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);
    }
 
 
    std::cout << "N patterns" << patterns.size() << std::endl;
}
 
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
        if(labelLeft != -1 && labelRight != -1) {
            unsigned int binLeft = grayToBinary(labelLeft);
            unsigned int binRight = grayToBinary(labelRight);
            // and differ in exactly one bit
            if (binRight + 1 == binLeft || binRight == binLeft + 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));
}
 
void AlgorithmGrayCode::get3DPoints(const SMCalibrationParameters &calibration, const std::vector<cv::Mat>& frames0, const std::vector<cv::Mat>& frames1, std::vector<cv::Point3f>& Q, std::vector<cv::Vec3f>& color){
 
    assert(frames0.size() == N);
    assert(frames1.size() == N);
 
    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);
 
    // 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_RGB2GRAY);
        cv::remap(temp, frames0Rect[i], map0X, map0Y, CV_INTER_LINEAR);
        cv::cvtColor(frames1[i], temp, CV_RGB2GRAY);
        cv::remap(temp, frames1Rect[i], map1X, map1Y, CV_INTER_LINEAR);
    }
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
    // color remap
    cv::Mat color0Rect, color1Rect;
    cv::remap(frames0[0], color0Rect, map0X, map0Y, CV_INTER_LINEAR);
    cv::remap(frames1[0], color1Rect, map1X, map1Y, CV_INTER_LINEAR);
 
    int frameRectRows = frames0Rect[0].rows;
    int frameRectCols = frames0Rect[0].cols;
 
    // occlusion masks
    cv::Mat occlusion0Rect, occlusion1Rect;
    cv::subtract(frames0Rect[0], frames0Rect[1], occlusion0Rect);
    occlusion0Rect = (occlusion0Rect > 0.1) & (occlusion0Rect < 0.99);
    cv::subtract(frames1Rect[0], frames1Rect[1], occlusion1Rect);
    occlusion1Rect = (occlusion1Rect > 0.1) & (occlusion1Rect < 0.99);
 
    // 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);
 
//    // 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];
//    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);
//    }
 
    // 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");
 
 
    #ifdef QT_DEBUG
        // 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");
    #endif
 
//    // 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);
 
 
    // 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;
        }
    }
 
 
#ifdef QT_DEBUG
    cv::imwrite("code0Rect.png", code0Rect);
    cv::imwrite("code1Rect.png", code1Rect);
#endif
 
    #ifdef QT_DEBUG
        cvtools::writeMat(code0Rect, "code0Rect.mat", "code0Rect");
        cvtools::writeMat(code1Rect, "code1Rect.mat", "code1Rect");
    #endif
 
    // matching
    std::vector<cv::Vec2f> q0, q1;
    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<float>(row, c0);
            float pos1 = frames0Rect[2*level+2].at<float>(row, c1);
            float neg0 = frames0Rect[2*level+3].at<float>(row, c0);
            float neg1 = frames0Rect[2*level+3].at<float>(row, c1);
 
            float col = c0 + (pos0 - neg0)/(neg1 - neg0 - pos1 + pos0);
            q0.push_back(cv::Point2f(col, row));
 
            // refine for camera 1
            c0 = matchedEdges1[i][0];
            c1 = c0+1;
 
            pos0 = frames1Rect[2*level+2].at<float>(row, c0);
            pos1 = frames1Rect[2*level+2].at<float>(row, c1);
            neg0 = frames1Rect[2*level+3].at<float>(row, c0);
            neg1 = frames1Rect[2*level+3].at<float>(row, c1);
 
            col = c0 + (pos0 - neg0)/(neg1 - neg0 - pos1 + pos0);
            q1.push_back(cv::Point2f(col, row));
 
        }
 
    }
 
    int nMatches = q0.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::Vec3f c0 = color0Rect.at<cv::Vec3f>(q0[i][1], q0[i][0]);
        cv::Vec3f c1 = color1Rect.at<cv::Vec3f>(q1[i][1], q1[i][0]);
 
        color[i] = 0.5*c0 + 0.5*c1;
    }
 
    // Triangulate by means of disparity projection
    Q.resize(q0.size());
    cv::Matx44f QRectx = cv::Matx44f(QRect);
    cv::Matx33f R0invx = cv::Matx33f(cv::Mat(R0.t()));
 
    #pragma omp parallel for
    for(unsigned int i=0; i<q0.size(); i++){
        float disparity = q0[i][0]-q1[i][0];
        cv::Vec4f Qih = QRectx*cv::Vec4f(q0[i][0], q0[i][1], disparity, 1.0);
        float winv = float(1.0)/Qih[3];
        Q[i] = R0invx * cv::Point3f(Qih[0]*winv, Qih[1]*winv, Qih[2]*winv);
    }
 
}
 

Subversion Repositories seema-scanner

(root)/src/algorithm/AlgorithmGrayCode.cpp – Rev 245 → 255

Rev 245		Rev 255
1	`//`	1	`//`
2	`// Gray Code Structured Light`	2	`// Gray Code Structured Light`
3	`//`	3	`//`
4	`// This implementation closely follows Henrik Aanaes, "Lecture Notes on Computer Vision" (2014).`	4	`// This implementation closely follows Henrik Aanaes, "Lecture Notes on Computer Vision" (2014).`
5	`//`	5	`//`
6		6
7	`#include "AlgorithmGrayCode.h"`	7	`#include "AlgorithmGrayCode.h"`
8	`#include <cmath>`	8	`#include <cmath>`
9	`#include "cvtools.h"`	9	`#include "cvtools.h"`
10	`#include "algorithmtools.h"`	10	`#include "algorithmtools.h"`
11		11
12	`// Algorithm`	12	`// Algorithm`
13	`AlgorithmGrayCode::AlgorithmGrayCode(unsigned int _screenCols, unsigned int _screenRows) : Algorithm(_screenCols, _screenRows){`	13	`AlgorithmGrayCode::AlgorithmGrayCode(unsigned int _screenCols, unsigned int _screenRows) : Algorithm(_screenCols, _screenRows){`
14		14
15	`Nbits = ceilf(log2f((float)screenCols)) - 1;`	15	`Nbits = 6;`
16	`N = 2 + Nbits*2;`	16	`N = 2 + Nbits*2;`
17		17
18	`// all on pattern`	18	`// all on pattern`
19	`cv::Mat allOn(1, screenCols, CV_8UC3, cv::Scalar::all(255));`	19	`cv::Mat allOn(1, screenCols, CV_8UC3, cv::Scalar::all(255));`
20	`patterns.push_back(allOn);`	20	`patterns.push_back(allOn);`
21		21
22	`// all off pattern`	22	`// all off pattern`
23	`cv::Mat allOff(1, screenCols, CV_8UC3, cv::Scalar::all(0));`	23	`cv::Mat allOff(1, screenCols, CV_8UC3, cv::Scalar::all(0));`
24	`patterns.push_back(allOff);`	24	`patterns.push_back(allOff);`
25		25
26		26
27	`// horizontally encoding patterns`	27	`// horizontally encoding patterns`
28	`for(unsigned int p=0; p<Nbits; p++){`	28	`for(unsigned int p=0; p<Nbits; p++){`
29	`cv::Mat pattern(1, screenCols, CV_8UC3);`	29	`cv::Mat pattern(1, screenCols, CV_8UC3);`
30	`cv::Mat patternInv(1, screenCols, CV_8UC3);`	30	`cv::Mat patternInv(1, screenCols, CV_8UC3);`
31		31
32	`for(unsigned int j=0; j<screenCols; j++){`	32	`for(unsigned int j=0; j<screenCols; j++){`
33		33
34	`unsigned int jGray = binaryToGray(j);`	34	`unsigned int jGray = binaryToGray(j);`
35	`// Amplitude of channels`	35	`// Amplitude of channels`
36	`int bit = (int)getBit(jGray, Nbits-p+1);`	36	`int bit = (int)getBit(jGray, Nbits-p+1);`
37	`pattern.at<cv::Vec3b>(0,j) = cv::Vec3b(255.0bit,255.0bit,255.0*bit);`	37	`pattern.at<cv::Vec3b>(0,j) = cv::Vec3b(255.0bit,255.0bit,255.0*bit);`
38	`int invBit = bit^1;`	38	`int invBit = bit^1;`
39	`patternInv.at<cv::Vec3b>(0,j) = cv::Vec3b(255.0invBit,255.0invBit,255.0*invBit);`	39	`patternInv.at<cv::Vec3b>(0,j) = cv::Vec3b(255.0invBit,255.0invBit,255.0*invBit);`
40	`}`	40	`}`