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


#include "AlgorithmLineShift.h"
#include <cmath>
#include "cvtools.h"
 
#include <opencv2/imgproc/imgproc.hpp>
 
#ifndef log2f
#define log2f(x) (log(x)/log(2.0))
#endif
 
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.
 *
 * 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 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
AlgorithmLineShift::AlgorithmLineShift(unsigned int _screenCols, unsigned int _screenRows) : Algorithm(_screenCols, _screenRows){
 
    nGrayBits = ceilf(log2f((float)screenCols)) - floorf(log2f((float)nLineShifts));
 
    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);
 
 
    // Gray code patterns
    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, 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::Scalar(0));
 
        for(unsigned int j=p; j<screenCols; j+= nLineShifts)
            pattern.at<cv::Vec3b>(0, j) = cv::Vec3b(255, 255, 255);
 
        patterns.push_back(pattern);
    }
 
}
 
cv::Mat AlgorithmLineShift::getEncodingPattern(unsigned int depth){
    return patterns[depth];
}
 
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 getlineCenters(const cv::Mat& linesScanLine, const cv::Mat& codeScanLine, std::vector<cv::Vec2f>& 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(cv::Vec2f(i, codeScanLine.at<unsigned char>(0, i)));
            // TODO: subpixel interpolation, non-max suppression
        }
 
    }
 
}
 
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);
 
    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(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(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");
 
    // color debayer and remap
    cv::Mat color0Rect, color1Rect;
    cv::cvtColor(frames0[0], color0Rect, CV_BayerBG2RGB);
    cv::remap(color0Rect, color0Rect, map0X, map0Y, CV_INTER_LINEAR);
 
    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;
 
    // 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);
 
    // 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);
    }
 
    //cvtools::writeMat(frames0Rect[22], "frames0Rect_22.mat", "frames0Rect_22");
    //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);
    std::vector<cv::Mat> frames0LineShift(frames0Rect.begin()+2+nGrayBits, frames0Rect.end());
    std::vector<cv::Mat> frames1GrayCode(frames1Rect.begin()+2, frames1Rect.begin()+2+nGrayBits);
    std::vector<cv::Mat> frames1LineShift(frames1Rect.begin()+2+nGrayBits, frames1Rect.end());
 
    // decode patterns
    cv::Mat code0Gray(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<nGrayBits; i++){
        cv::Mat temp, bit0, bit1;
 
        cv::compare(frames0GrayCode[i*2], frames0GrayCode[i*2+1], temp, cv::CMP_GT);
        temp.convertTo(bit0, CV_32S, 1.0/255.0);
        cv::add(code0Gray, bit0*twopowi(nGrayBits-i-1), code0Gray, cv::noArray(), CV_32S);
 
        cv::compare(frames1GrayCode[i*2], frames1GrayCode[i*2+1], temp, cv::CMP_GT);
        temp.convertTo(bit1, CV_32S, 1.0/255.0);
        cv::add(code1Gray, bit1*twopowi(nGrayBits-i-1), code1Gray, cv::noArray(), CV_32S);
    }
 
    // 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)
                code0Gray.at<int>(r,c) = -1;
            if(occlusion1Rect.at<unsigned char>(r,c) == 0)
                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(code0Gray, "code0Gray.mat", "code0Gray");
    //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++){
 
        // line center data structure containing [x-coordinate (sub-px), region-code]
        std::vector<cv::Vec2f> lineCenters0, lineCenters1;
 
        // sorted, unique line centers
        getlineCenters(lines0.row(row), code0Binary.row(row), lineCenters0);
        getlineCenters(lines1.row(row), code1Binary.row(row), lineCenters1);
 
        // match and store
        int i=0, j=0;
        while(i<lineCenters0.size() && j<lineCenters1.size()){
 
            if(lineCenters0[i][1] == lineCenters1[j][1]){
                q0Rect.push_back(cv::Point2f(lineCenters0[0][0], row));
                q1Rect.push_back(cv::Point2f(lineCenters1[0][0], row));
                i += 1;
                j += 1;
            } else if(lineCenters0[i][1] < lineCenters1[j][1]){
                i += 1;
            } else if(lineCenters0[i][1] > lineCenters1[j][1]){
                j += 1;
            }
        }
 
    }
 
    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::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/AlgorithmLineShift.cpp – Rev 123 → 124

Rev 123		Rev 124
1	`#include "AlgorithmLineShift.h"`	1	`#include "AlgorithmLineShift.h"`
2	`#include <cmath>`	2	`#include <cmath>`
3	`#include "cvtools.h"`	3	`#include "cvtools.h"`
4		4
5	`#include <opencv2/imgproc.hpp>`	5	`#include <opencv2/imgproc/imgproc.hpp>`
6		6
7	`#ifndef log2f`	7	`#ifndef log2f`
8	`#define log2f(x) (log(x)/log(2.0))`	8	`#define log2f(x) (log(x)/log(2.0))`
9	`#endif`	9	`#endif`
10		10
11	`static unsigned int nLineShifts = 8; // number of columns over which each line is shifted`	11	`static unsigned int nLineShifts = 8; // number of columns over which each line is shifted`
12		12
13	`/*`	13	`/*`
14	`* The purpose of this function is to convert an unsigned`	14	`* The purpose of this function is to convert an unsigned`
15	`* binary number to reflected binary Gray code.`	15	`* binary number to reflected binary Gray code.`
16	`*`	16	`*`
17	`* The operator >> is shift right. The operator ^ is exclusive or.`	17	`* The operator >> is shift right. The operator ^ is exclusive or.`
18	`* Source: http://en.wikipedia.org/wiki/Gray_code`	18	`* Source: http://en.wikipedia.org/wiki/Gray_code`
19	`*/`	19	`*/`
20	`static unsigned int binaryToGray(unsigned int num) {`	20	`static unsigned int binaryToGray(unsigned int num) {`
21	`return (num >> 1) ^ num;`	21	`return (num >> 1) ^ num;`
22	`}`	22	`}`
23		23
24	`/*`	24	`/*`
25	`* From Wikipedia: http://en.wikipedia.org/wiki/Gray_code`	25	`* From Wikipedia: http://en.wikipedia.org/wiki/Gray_code`
26	`* The purpose of this function is to convert a reflected binary`	26	`* The purpose of this function is to convert a reflected binary`
27	`* Gray code number to a binary number.`	27	`* Gray code number to a binary number.`
28	`*/`	28	`*/`
29	`static unsigned int grayToBinary(unsigned int num){`	29	`static unsigned int grayToBinary(unsigned int num){`
30	`unsigned int mask;`	30	`unsigned int mask;`
31	`for(mask = num >> 1; mask != 0; mask = mask >> 1)`	31	`for(mask = num >> 1; mask != 0; mask = mask >> 1)`
32	`num = num ^ mask;`	32	`num = num ^ mask;`
33	`return num;`	33	`return num;`
34	`}`	34	`}`
35		35
36	`/*`	36	`/*`
37	`* Return the Nth bit of an unsigned integer number`	37	`* Return the Nth bit of an unsigned integer number`
38	`*/`	38	`*/`
39	`static bool getBit(int decimal, int N){`	39	`static bool getBit(int decimal, int N){`
40		40