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#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 grayToBinary(unsigned num, unsigned numBits)
{
for (unsigned shift = 1; shift < numBits; shift <<= 1){
num ^= num >> shift;
}
return num;
}
/*
* Function takes the decimal number
* Function takes the Nth bit (1 to 31)
* Return the value of Nth bit from decimal
* Source: http://icfun.blogspot.com/2009/04/get-n-th-bit-value-of-any-integer.html
*/
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;
}
// If the bit is not set, return 0
return 0;
}
static inline int powi(int num, unsigned int exponent){
// NOT EQUIVALENT TO pow()
if(exponent == 0)
return 1;
float res = num;
for(unsigned int i=0; i<exponent-1; i++)
res *= num;
return res;
}
// 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 = get_bit(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 sortingEqual(cv::Vec4f i,cv::Vec4f j){ return (i[3]==j[3]);}
void getEdgeLabels(const cv::Mat& scanLine, int Nbits, std::vector<cv::Vec4f>& edges){
int nCols = scanLine.cols;
const short *data = scanLine.ptr<const short>(0);
short labelLeft;
short labelRight = data[0];
// collect edges
for(int col=1; col<nCols; col++){
labelLeft = labelRight;
labelRight = data[col];
if(labelLeft != -1 && labelRight != -1 && labelLeft != labelRight){
int orderingRelation = (labelLeft << Nbits) + labelRight;
edges.push_back(cv::Vec4f(col-0.5, labelLeft, labelRight, orderingRelation));
}
}
// sort
std::sort(edges.begin(), edges.end(), sortingLarger);
// remove duplicates
std::vector<cv::Vec4f>::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);
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(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 remaps
cv::Mat color0Rect, color1Rect;
cv::remap(frames0[0], color0Rect, map0X, map0Y, CV_INTER_CUBIC);
cv::remap(frames1[0], color1Rect, map0X, map0Y, CV_INTER_CUBIC);
int frameRectRows = frames0Rect[0].rows;
int frameRectCols = frames0Rect[0].cols;
// occlusion maps
cv::Mat occlusion0Rect, occlusion1Rect;
cv::subtract(frames0Rect[0], frames0Rect[1], occlusion0Rect);
occlusion0Rect = occlusion0Rect > 50;
cv::subtract(frames1Rect[0], frames1Rect[1], occlusion1Rect);
occlusion1Rect = occlusion1Rect > 50;
//cvtools::writeMat(occlusion0Rect, "occlusion0Rect.mat", "occlusion0Rect");
//cvtools::writeMat(occlusion1Rect, "occlusion1Rect.mat", "occlusion1Rect");
// decode patterns
cv::Mat code0Rect(frameRectRows, frameRectCols, CV_16S, cv::Scalar(-1));
cv::Mat code1Rect(frameRectRows, frameRectCols, CV_16S, cv::Scalar(-1));
cv::add(code0Rect, 1, code0Rect, occlusion0Rect, CV_16S);
cv::add(code1Rect, 1, code1Rect, occlusion1Rect, CV_16S);
for(int i=0; i<Nbits; i++){
cv::Mat bit0;
cv::subtract(frames0Rect[i*2+2], frames0Rect[i*2+3], bit0, cv::noArray(), CV_16S);
bit0 = bit0 > 0;
// cvtools::writeMat(bit0, "bit0.mat", "bit0");
cv::add(code0Rect, bit0/255*powi(2,i), code0Rect, occlusion0Rect, CV_16S);
// cvtools::writeMat(code0Rect, "code0Rect.mat", "code0Rect");
cv::Mat bit1;
cv::subtract(frames1Rect[i*2+2], frames1Rect[i*2+3], bit1, cv::noArray(), CV_16S);
bit1 = bit1 > 0;
cv::add(code1Rect, bit1/255*powi(2,i), code1Rect, occlusion1Rect, CV_16S);
}
//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;
// sorted, unique edges
getEdgeLabels(code0Rect.row(row), Nbits, edges0);
getEdgeLabels(code1Rect.row(row), Nbits, edges1);
// subpixel refinement
// ...
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));
q1Rect.push_back(cv::Vec2f(edges1[j][0], row));
i += 1;
j += 1;
} else if(edges0[i][3] < edges1[j][3]){
i += 1;
} else if(edges0[i][3] > edges1[j][3]){
j += 1;
}
}
}
// 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 + c1);
}
// triangulate points
cv::Mat QMatHomogenous, QMat;
cv::triangulatePoints(P0, P1, q0Rect, q1Rect, QMatHomogenous);
cvtools::convertMatFromHomogeneous(QMatHomogenous, QMat);
cvtools::matToPoints3f(QMat, Q);
}