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TextDetection.cpp
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/*
Copyright 2012 Andrew Perrault and Saurav Kumar.
This file is part of DetectText.
DetectText is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
DetectText is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with DetectText. If not, see <http://www.gnu.org/licenses/>.
*/
#include <boost/graph/adjacency_list.hpp>
#include <boost/graph/graph_traits.hpp>
#include <boost/graph/connected_components.hpp>
#include <boost/unordered_map.hpp>
#include <boost/graph/floyd_warshall_shortest.hpp>
#include <boost/numeric/ublas/matrix.hpp>
#include <boost/numeric/ublas/io.hpp>
/*#include <graph/adjacency_list.hpp>
#include <graph/graph_traits.hpp>
#include <graph/connected_components.hpp>
#include <unordered_map.hpp>
#include <graph/floyd_warshall_shortest.hpp>
#include <numeric/ublas/matrix.hpp>
#include <numeric/ublas/io.hpp> */
#include <cassert>
#include <cmath>
#include <iostream>
#include <opencv/cv.h>
#include <opencv/highgui.h>
#include <opencv/cxcore.h>
#include <math.h>
#include <time.h>
#include <utility>
#include <algorithm>
#include <vector>
#include <TextDetection.h>
#include <tesseract/baseapi.h>
#include <tesseract/strngs.h>
#include <iostream>
#define PI 3.14159265
#define MAX_TORSO_TO_BIB_RATIO_X (4)
std::vector<std::pair<CvPoint,CvPoint> > findBoundingBoxes( std::vector<std::vector<Point2d> > & components,
std::vector<Chain> & chains,
std::vector<std::pair<Point2d,Point2d> > & compBB,
IplImage * output) {
std::vector<std::pair<CvPoint,CvPoint> > bb;
bb.reserve(chains.size());
for (std::vector<Chain>::iterator chainit = chains.begin(); chainit != chains.end(); chainit++) {
int minx = output->width;
int miny = output->height;
int maxx = 0;
int maxy = 0;
for (std::vector<int>::const_iterator cit = chainit->components.begin(); cit != chainit->components.end(); cit++) {
miny = std::min(miny,compBB[*cit].first.y);
minx = std::min(minx,compBB[*cit].first.x);
maxy = std::max(maxy,compBB[*cit].second.y);
maxx = std::max(maxx,compBB[*cit].second.x);
}
CvPoint p0 = cvPoint(minx,miny);
CvPoint p1 = cvPoint(maxx,maxy);
std::pair<CvPoint,CvPoint> pair(p0,p1);
bb.push_back(pair);
}
return bb;
}
std::vector<std::vector<CvPoint> > findBoundingTrapeze( std::vector<std::vector<Point2d> > & components,
std::vector<Chain> & chains,
std::vector<std::pair<Point2d,Point2d> > & compBB,
IplImage * output) {
std::vector<std::vector<CvPoint> > bt;
bt.reserve(chains.size());
for (std::vector<Chain>::iterator chainit = chains.begin(); chainit != chains.end(); chainit++) {
int minx = output->width;
int maxx = 0;
int leftmostComponent = 0;
int rightmostComponent = 0;
for (std::vector<int>::const_iterator cit = chainit->components.begin(); cit != chainit->components.end(); cit++) {
if (compBB[*cit].first.x <= minx)
{
minx = compBB[*cit].first.x;
leftmostComponent = *cit;
}
if (compBB[*cit].second.x >= maxx)
{
maxx = compBB[*cit].second.x;
rightmostComponent = *cit;
}
}
if ( maxx-minx > output->width/MAX_TORSO_TO_BIB_RATIO_X)
{
CvPoint topLeft = cvPoint(compBB[leftmostComponent].first.x, compBB[leftmostComponent].first.y );
CvPoint bottomLeft = cvPoint(compBB[leftmostComponent].first.x, compBB[leftmostComponent].second.y );
CvPoint topRight = cvPoint(compBB[rightmostComponent].second.x, compBB[rightmostComponent].first.y );
CvPoint bottomRight = cvPoint(compBB[rightmostComponent].second.x, compBB[rightmostComponent].second.y );
std::vector<CvPoint> trapeze;
trapeze.push_back(topLeft);
trapeze.push_back(bottomLeft);
trapeze.push_back(topRight);
trapeze.push_back(bottomRight);
bt.push_back(trapeze);
std::cout << "Trapeze: "
<< "(" << topLeft.x << "," << topLeft.y
<< "),(" << bottomLeft.x << "," << bottomLeft.y
<< "),(" << topRight.x << "," << topRight.y
<< "),(" << bottomRight.x << "," << bottomRight.y << ")"
<< std::endl;
}
}
return bt;
}
std::vector<std::pair<CvPoint,CvPoint> > findBoundingBoxes( std::vector<std::vector<Point2d> > & components,
IplImage * output) {
std::vector<std::pair<CvPoint,CvPoint> > bb;
bb.reserve(components.size());
for (std::vector<std::vector<Point2d> >::iterator compit = components.begin(); compit != components.end(); compit++) {
int minx = output->width;
int miny = output->height;
int maxx = 0;
int maxy = 0;
for (std::vector<Point2d>::iterator it = compit->begin(); it != compit->end(); it++) {
miny = std::min(miny,it->y);
minx = std::min(minx,it->x);
maxy = std::max(maxy,it->y);
maxx = std::max(maxx,it->x);
}
CvPoint p0 = cvPoint(minx,miny);
CvPoint p1 = cvPoint(maxx,maxy);
std::pair<CvPoint,CvPoint> pair(p0,p1);
bb.push_back(pair);
}
return bb;
}
void normalizeImage (IplImage * input, IplImage * output) {
assert ( input->depth == IPL_DEPTH_32F );
assert ( input->nChannels == 1 );
assert ( output->depth == IPL_DEPTH_32F );
assert ( output->nChannels == 1 );
float maxVal = 0;
float minVal = 1e100;
for( int row = 0; row < input->height; row++ ){
const float* ptr = (const float*)(input->imageData + row * input->widthStep);
for ( int col = 0; col < input->width; col++ ){
if (*ptr < 0) { }
else {
maxVal = std::max(*ptr, maxVal);
minVal = std::min(*ptr, minVal);
}
ptr++;
}
}
float difference = maxVal - minVal;
for( int row = 0; row < input->height; row++ ){
const float* ptrin = (const float*)(input->imageData + row * input->widthStep);\
float* ptrout = (float*)(output->imageData + row * output->widthStep);\
for ( int col = 0; col < input->width; col++ ){
if (*ptrin < 0) {
*ptrout = 1;
} else {
*ptrout = ((*ptrin) - minVal)/difference;
}
ptrout++;
ptrin++;
}
}
}
void renderComponents (IplImage * SWTImage, std::vector<std::vector<Point2d> > & components, IplImage * output) {
cvZero(output);
for (std::vector<std::vector<Point2d> >::iterator it = components.begin(); it != components.end();it++) {
for (std::vector<Point2d>::iterator pit = it->begin(); pit != it->end(); pit++) {
CV_IMAGE_ELEM(output, float, pit->y, pit->x) = CV_IMAGE_ELEM(SWTImage, float, pit->y, pit->x);
}
}
for( int row = 0; row < output->height; row++ ){
float* ptr = (float*)(output->imageData + row * output->widthStep);
for ( int col = 0; col < output->width; col++ ){
if (*ptr == 0) {
*ptr = -1;
}
ptr++;
}
}
float maxVal = 0;
float minVal = 1e100;
for( int row = 0; row < output->height; row++ ){
const float* ptr = (const float*)(output->imageData + row * output->widthStep);
for ( int col = 0; col < output->width; col++ ){
if (*ptr == 0) { }
else {
maxVal = std::max(*ptr, maxVal);
minVal = std::min(*ptr, minVal);
}
ptr++;
}
}
float difference = maxVal - minVal;
for( int row = 0; row < output->height; row++ ){
float* ptr = (float*)(output->imageData + row * output->widthStep);\
for ( int col = 0; col < output->width; col++ ){
if (*ptr < 1) {
*ptr = 1;
} else {
*ptr = ((*ptr) - minVal)/difference;
}
ptr++;
}
}
}
void renderComponentsWithBoxes (IplImage * SWTImage, std::vector<std::vector<Point2d> > & components,
std::vector<std::pair<Point2d,Point2d> > & compBB, IplImage * output) {
IplImage * outTemp =
cvCreateImage ( cvGetSize ( output ), IPL_DEPTH_32F, 1 );
renderComponents(SWTImage,components,outTemp);
std::vector<std::pair<CvPoint,CvPoint> > bb;
bb.reserve(compBB.size());
for (std::vector<std::pair<Point2d,Point2d> >::iterator it=compBB.begin(); it != compBB.end(); it++ ) {
CvPoint p0 = cvPoint(it->first.x,it->first.y);
CvPoint p1 = cvPoint(it->second.x,it->second.y);
std::pair<CvPoint,CvPoint> pair(p0,p1);
bb.push_back(pair);
}
IplImage * out =
cvCreateImage ( cvGetSize ( output ), IPL_DEPTH_8U, 1 );
cvConvertScale(outTemp, out, 255, 0);
cvCvtColor (out, output, CV_GRAY2RGB);
//cvReleaseImage ( &outTemp );
//cvReleaseImage ( &out );
int count = 0;
for (std::vector<std::pair<CvPoint,CvPoint> >::iterator it= bb.begin(); it != bb.end(); it++) {
CvScalar c;
if (count % 3 == 0) c=cvScalar(255,0,0);
else if (count % 3 == 1) c=cvScalar(0,255,0);
else c=cvScalar(0,0,255);
cvRectangle(output, it->first,it->second, c);
count++;
}
}
void renderChainsWithBoxes (IplImage * SWTImage,
std::vector<std::vector<Point2d> > & components,
std::vector<Chain> & chains,
std::vector<std::pair<Point2d,Point2d> > & compBB,
IplImage * output,
IplImage * input
) {
// keep track of included components
std::vector<bool> included;
included.reserve(components.size());
for (unsigned int i = 0; i != components.size(); i++) {
included.push_back(false);
}
for (std::vector<Chain>::iterator it = chains.begin(); it != chains.end();it++) {
for (std::vector<int>::iterator cit = it->components.begin(); cit != it->components.end(); cit++) {
included[*cit] = true;
}
}
std::vector<std::vector<Point2d> > componentsRed;
for (unsigned int i = 0; i != components.size(); i++ ) {
if (included[i]) {
componentsRed.push_back(components[i]);
}
}
IplImage * outTemp =
cvCreateImage ( cvGetSize ( output ), IPL_DEPTH_32F, 1 );
std::cout << componentsRed.size() << " components after chaining" << std::endl;
renderComponents(SWTImage,componentsRed,outTemp);
std::vector<std::pair<CvPoint,CvPoint> > bb;
bb = findBoundingBoxes(components, chains, compBB, outTemp);
std::vector<std::vector<CvPoint> > bt;
bt = findBoundingTrapeze(components, chains, compBB, outTemp);
IplImage * out =
cvCreateImage ( cvGetSize ( output ), IPL_DEPTH_8U, 1 );
cvConvertScale(outTemp, out, 255, 0);
cvCvtColor (out, output, CV_GRAY2RGB);
cvReleaseImage ( &out );
cvReleaseImage ( &outTemp);
#if 0
int count = 0;
for (std::vector<std::pair<CvPoint,CvPoint> >::iterator it= bb.begin(); it != bb.end(); it++) {
CvScalar c;
if (count % 3 == 0) c=cvScalar(255,0,0);
else if (count % 3 == 1) c=cvScalar(0,255,0);
else c=cvScalar(0,0,255);
count++;
cvRectangle(output,it->first,it->second,c,2);
cv::Rect roi = cv::Rect(it->first, it->second);
if (roi.width > input->width/MAX_TORSO_TO_BIB_RATIO_X)
{
cv::Mat mat_roi = cv::Mat(input)(roi);
cv::Mat mat;
cv::threshold(mat_roi, mat
, 0 // the value doesn't matter for Otsu thresholding
, 255 // we could choose any non-zero value. 255 (white) makes it easy to see the binary image
, cv::THRESH_OTSU | cv::THRESH_BINARY_INV);
cv::imwrite ( "bib-tess-input.png", mat);
}
# else
for (std::vector<std::vector<CvPoint> >::iterator it= bt.begin(); it != bt.end(); it++) {
CvPoint topLeft = (*it)[0];
CvPoint bottomLeft = (*it)[1];
CvPoint topRight = (*it)[2];
CvPoint bottomRight = (*it)[3];
double theta_rad = atan2( bottomRight.y - bottomLeft.y, bottomRight.x - bottomLeft.x);
double theta_deg = (theta_rad/PI) * 180;
printf("%f degrees\n", theta_deg);
cv::Mat rotMatrix = cv::getRotationMatrix2D(bottomLeft, theta_deg , 1.0);
cv::Mat inputMat = cv::Mat(input);
cv::Mat rotatedMat = cv::Mat::zeros( inputMat.rows, inputMat.cols, inputMat.type() );
cv::warpAffine( inputMat, rotatedMat, rotMatrix, rotatedMat.size() );
CvPoint newTopLeft = cvPoint(std::max(0, topLeft.x-4), std::max(0, topLeft.y-4));
CvPoint newBottomRight = cvPoint(std::min(inputMat.cols, bottomRight.x+2),std::min(inputMat.rows, bottomLeft.y+2));
cv::Rect roi = cv::Rect(newTopLeft, newBottomRight);
cv::Mat mat_roi = rotatedMat(roi);
cv::Mat mat;
cv::threshold(mat_roi, mat
, 0 // the value doesn't matter for Otsu thresholding
, 255 // we could choose any non-zero value. 255 (white) makes it easy to see the binary image
, cv::THRESH_OTSU | cv::THRESH_BINARY_INV);
cv::imwrite ( "bib-tess-input.png", mat);
// Pass it to Tesseract API
tesseract::TessBaseAPI tess;
tess.Init(NULL, "eng", tesseract::OEM_DEFAULT);
tess.SetVariable("tessedit_char_whitelist", "0123456789");
tess.SetVariable("tessedit_write_images", "true");
tess.SetPageSegMode(tesseract::PSM_SINGLE_WORD);
tess.SetImage((uchar*)mat.data, mat.cols, mat.rows, 1, mat.step1());
// Get the text
char* out = tess.GetUTF8Text();
std::cout << "Mat text: " << out << std::endl;
cv::rectangle(rotatedMat,roi,cvScalar(0,0,255),2);
cv::imwrite("bib-rotated.png", rotatedMat);
}
# endif
}
void renderChains (IplImage * SWTImage,
std::vector<std::vector<Point2d> > & components,
std::vector<Chain> & chains,
IplImage * output) {
// keep track of included components
std::vector<bool> included;
included.reserve(components.size());
for (unsigned int i = 0; i != components.size(); i++) {
included.push_back(false);
}
for (std::vector<Chain>::iterator it = chains.begin(); it != chains.end();it++) {
for (std::vector<int>::iterator cit = it->components.begin(); cit != it->components.end(); cit++) {
included[*cit] = true;
}
}
std::vector<std::vector<Point2d> > componentsRed;
for (unsigned int i = 0; i != components.size(); i++ ) {
if (included[i]) {
componentsRed.push_back(components[i]);
}
}
std::cout << componentsRed.size() << " components after chaining" << std::endl;
IplImage * outTemp =
cvCreateImage ( cvGetSize ( output ), IPL_DEPTH_32F, 1 );
renderComponents(SWTImage,componentsRed,outTemp);
cvConvertScale(outTemp, output, 255, 0);
cvReleaseImage(&outTemp);
}
IplImage * textDetection (IplImage * input, bool dark_on_light)
{
assert ( input->depth == IPL_DEPTH_8U );
assert ( input->nChannels == 3 );
std::cout << "---------------------------------------- " << std::endl;
std::cout << "Running textDetection with dark_on_light " << dark_on_light << std::endl;
// Convert to grayscale
IplImage * grayImage =
cvCreateImage ( cvGetSize ( input ), IPL_DEPTH_8U, 1 );
cvCvtColor ( input, grayImage, CV_RGB2GRAY );
// Create Canny Image
double threshold_low = 175;
double threshold_high = 320;
IplImage * edgeImage =
cvCreateImage( cvGetSize (input),IPL_DEPTH_8U, 1 );
cvCanny(grayImage, edgeImage, threshold_low, threshold_high, 3) ;
cvSaveImage ( "canny.png", edgeImage);
// Create gradient X, gradient Y
IplImage * gaussianImage =
cvCreateImage ( cvGetSize(input), IPL_DEPTH_32F, 1);
cvConvertScale (grayImage, gaussianImage, 1./255., 0);
cvSmooth( gaussianImage, gaussianImage, CV_GAUSSIAN, 5, 5);
IplImage * gradientX =
cvCreateImage ( cvGetSize ( input ), IPL_DEPTH_32F, 1 );
IplImage * gradientY =
cvCreateImage ( cvGetSize ( input ), IPL_DEPTH_32F, 1 );
cvSobel(gaussianImage, gradientX , 1, 0, CV_SCHARR);
cvSobel(gaussianImage, gradientY , 0, 1, CV_SCHARR);
cvSmooth(gradientX, gradientX, 3, 3);
cvSmooth(gradientY, gradientY, 3, 3);
cvReleaseImage ( &gaussianImage );
// Calculate SWT and return ray vectors
std::vector<Ray> rays;
IplImage * SWTImage =
cvCreateImage ( cvGetSize ( input ), IPL_DEPTH_32F, 1 );
for( int row = 0; row < input->height; row++ ){
float* ptr = (float*)(SWTImage->imageData + row * SWTImage->widthStep);
for ( int col = 0; col < input->width; col++ ){
*ptr++ = -1;
}
}
strokeWidthTransform ( edgeImage, gradientX, gradientY, dark_on_light, SWTImage, rays );
SWTMedianFilter ( SWTImage, rays );
IplImage * output2 =
cvCreateImage ( cvGetSize ( input ), IPL_DEPTH_32F, 1 );
normalizeImage (SWTImage, output2);
IplImage * saveSWT =
cvCreateImage ( cvGetSize ( input ), IPL_DEPTH_8U, 1 );
cvConvertScale(output2, saveSWT, 255, 0);
cvSaveImage ( "SWT.png", saveSWT);
cvReleaseImage ( &output2 );
cvReleaseImage( &saveSWT );
// Calculate legally connected components from SWT and gradient image.
// return type is a vector of vectors, where each outer vector is a component and
// the inner vector contains the (y,x) of each pixel in that component.
std::vector<std::vector<Point2d> > components = findLegallyConnectedComponents(SWTImage, rays);
// Filter the components
std::vector<std::vector<Point2d> > validComponents;
std::vector<std::pair<Point2d,Point2d> > compBB;
std::vector<Point2dFloat> compCenters;
std::vector<float> compMedians;
std::vector<Point2d> compDimensions;
filterComponents(SWTImage, components, validComponents, compCenters, compMedians, compDimensions, compBB );
IplImage * output3 =
cvCreateImage ( cvGetSize ( input ), 8U, 3 );
renderComponentsWithBoxes (SWTImage, validComponents, compBB, output3);
cvSaveImage ( "components.png",output3);
//cvReleaseImage ( &output3 );
// Make chains of components
std::vector<Chain> chains;
chains = makeChains(input, validComponents, compCenters, compMedians, compDimensions, compBB);
IplImage * output4 =
cvCreateImage ( cvGetSize ( input ), IPL_DEPTH_8U, 1 );
renderChains ( SWTImage, validComponents, chains, output4 );
cvSaveImage ( "text.png", output4);
IplImage * output5 =
cvCreateImage ( cvGetSize ( input ), IPL_DEPTH_8U, 3 );
cvCvtColor (output4, output5, CV_GRAY2RGB);
cvReleaseImage ( &output4 );
IplImage * output =
cvCreateImage ( cvGetSize ( input ), IPL_DEPTH_8U, 3 );
renderChainsWithBoxes ( SWTImage, validComponents, chains, compBB, output, grayImage);
cvSaveImage ( "text-boxes.png", output);
cvReleaseImage ( &output );
cvReleaseImage ( &gradientX );
cvReleaseImage ( &gradientY );
cvReleaseImage ( &SWTImage );
cvReleaseImage ( &edgeImage );
cvReleaseImage ( &grayImage );
return output5;
}
void strokeWidthTransform (IplImage * edgeImage,
IplImage * gradientX,
IplImage * gradientY,
bool dark_on_light,
IplImage * SWTImage,
std::vector<Ray> & rays) {
// First pass
float prec = .05;
for( int row = 0; row < edgeImage->height; row++ ){
const uchar* ptr = (const uchar*)(edgeImage->imageData + row * edgeImage->widthStep);
for ( int col = 0; col < edgeImage->width; col++ ){
if (*ptr > 0) {
Ray r;
Point2d p;
p.x = col;
p.y = row;
r.p = p;
std::vector<Point2d> points;
points.push_back(p);
float curX = (float)col + 0.5;
float curY = (float)row + 0.5;
int curPixX = col;
int curPixY = row;
float G_x = CV_IMAGE_ELEM ( gradientX, float, row, col);
float G_y = CV_IMAGE_ELEM ( gradientY, float, row, col);
// normalize gradient
float mag = sqrt( (G_x * G_x) + (G_y * G_y) );
if (dark_on_light){
G_x = -G_x/mag;
G_y = -G_y/mag;
} else {
G_x = G_x/mag;
G_y = G_y/mag;
}
while (true) {
curX += G_x*prec;
curY += G_y*prec;
if ((int)(floor(curX)) != curPixX || (int)(floor(curY)) != curPixY) {
curPixX = (int)(floor(curX));
curPixY = (int)(floor(curY));
// check if pixel is outside boundary of image
if (curPixX < 0 || (curPixX >= SWTImage->width) || curPixY < 0 || (curPixY >= SWTImage->height)) {
break;
}
Point2d pnew;
pnew.x = curPixX;
pnew.y = curPixY;
points.push_back(pnew);
if (CV_IMAGE_ELEM ( edgeImage, uchar, curPixY, curPixX) > 0) {
r.q = pnew;
// dot product
float G_xt = CV_IMAGE_ELEM(gradientX,float,curPixY,curPixX);
float G_yt = CV_IMAGE_ELEM(gradientY,float,curPixY,curPixX);
mag = sqrt( (G_xt * G_xt) + (G_yt * G_yt) );
if (dark_on_light){
G_xt = -G_xt/mag;
G_yt = -G_yt/mag;
} else {
G_xt = G_xt/mag;
G_yt = G_yt/mag;
}
if (acos(G_x * -G_xt + G_y * -G_yt) < PI/2.0 ) {
float length = sqrt( ((float)r.q.x - (float)r.p.x)*((float)r.q.x - (float)r.p.x) + ((float)r.q.y - (float)r.p.y)*((float)r.q.y - (float)r.p.y));
for (std::vector<Point2d>::iterator pit = points.begin(); pit != points.end(); pit++) {
if (CV_IMAGE_ELEM(SWTImage, float, pit->y, pit->x) < 0) {
CV_IMAGE_ELEM(SWTImage, float, pit->y, pit->x) = length;
} else {
CV_IMAGE_ELEM(SWTImage, float, pit->y, pit->x) = std::min(length, CV_IMAGE_ELEM(SWTImage, float, pit->y, pit->x));
}
}
r.points = points;
rays.push_back(r);
}
break;
}
}
}
}
ptr++;
}
}
}
void SWTMedianFilter (IplImage * SWTImage,
std::vector<Ray> & rays) {
for (std::vector<Ray>::iterator rit = rays.begin(); rit != rays.end(); rit++) {
for (std::vector<Point2d>::iterator pit = rit->points.begin(); pit != rit->points.end(); pit++) {
pit->SWT = CV_IMAGE_ELEM(SWTImage, float, pit->y, pit->x);
}
std::sort(rit->points.begin(), rit->points.end(), &Point2dSort);
float median = (rit->points[rit->points.size()/2]).SWT;
for (std::vector<Point2d>::iterator pit = rit->points.begin(); pit != rit->points.end(); pit++) {
CV_IMAGE_ELEM(SWTImage, float, pit->y, pit->x) = std::min(pit->SWT, median);
}
}
}
bool Point2dSort (const Point2d &lhs, const Point2d &rhs) {
return lhs.SWT < rhs.SWT;
}
std::vector< std::vector<Point2d> >
findLegallyConnectedComponents (IplImage * SWTImage,
std::vector<Ray> & rays)
{
boost::unordered_map<int, int> map;
boost::unordered_map<int, Point2d> revmap;
typedef boost::adjacency_list<boost::vecS, boost::vecS, boost::undirectedS> Graph;
int num_vertices = 0;
// Number vertices for graph. Associate each point with number
for( int row = 0; row < SWTImage->height; row++ ){
float * ptr = (float*)(SWTImage->imageData + row * SWTImage->widthStep);
for (int col = 0; col < SWTImage->width; col++ ){
if (*ptr > 0) {
map[row * SWTImage->width + col] = num_vertices;
Point2d p;
p.x = col;
p.y = row;
revmap[num_vertices] = p;
num_vertices++;
}
ptr++;
}
}
Graph g(num_vertices);
for( int row = 0; row < SWTImage->height; row++ ){
float * ptr = (float*)(SWTImage->imageData + row * SWTImage->widthStep);
for (int col = 0; col < SWTImage->width; col++ ){
if (*ptr > 0) {
// check pixel to the right, right-down, down, left-down
int this_pixel = map[row * SWTImage->width + col];
if (col+1 < SWTImage->width) {
float right = CV_IMAGE_ELEM(SWTImage, float, row, col+1);
if (right > 0 && ((*ptr)/right <= 3.0 || right/(*ptr) <= 3.0))
boost::add_edge(this_pixel, map.at(row * SWTImage->width + col + 1), g);
}
if (row+1 < SWTImage->height) {
if (col+1 < SWTImage->width) {
float right_down = CV_IMAGE_ELEM(SWTImage, float, row+1, col+1);
if (right_down > 0 && ((*ptr)/right_down <= 3.0 || right_down/(*ptr) <= 3.0))
boost::add_edge(this_pixel, map.at((row+1) * SWTImage->width + col + 1), g);
}
float down = CV_IMAGE_ELEM(SWTImage, float, row+1, col);
if (down > 0 && ((*ptr)/down <= 3.0 || down/(*ptr) <= 3.0))
boost::add_edge(this_pixel, map.at((row+1) * SWTImage->width + col), g);
if (col-1 >= 0) {
float left_down = CV_IMAGE_ELEM(SWTImage, float, row+1, col-1);
if (left_down > 0 && ((*ptr)/left_down <= 3.0 || left_down/(*ptr) <= 3.0))
boost::add_edge(this_pixel, map.at((row+1) * SWTImage->width + col - 1), g);
}
}
}
ptr++;
}
}
std::vector<int> c(num_vertices);
int num_comp = connected_components(g, &c[0]);
std::vector<std::vector<Point2d> > components;
components.reserve(num_comp);
std::cout << "Before filtering, " << num_comp << " components and " << num_vertices << " vertices" << std::endl;
for (int j = 0; j < num_comp; j++) {
std::vector<Point2d> tmp;
components.push_back( tmp );
}
for (int j = 0; j < num_vertices; j++) {
Point2d p = revmap[j];
(components[c[j]]).push_back(p);
}
return components;
}
void componentStats(IplImage * SWTImage,
const std::vector<Point2d> & component,
float & mean, float & variance, float & median,
int & minx, int & miny, int & maxx, int & maxy)
{
std::vector<float> temp;
temp.reserve(component.size());
mean = 0;
variance = 0;
minx = 1000000;
miny = 1000000;
maxx = 0;
maxy = 0;
for (std::vector<Point2d>::const_iterator it = component.begin(); it != component.end(); it++) {
float t = CV_IMAGE_ELEM(SWTImage, float, it->y, it->x);
mean += t;
temp.push_back(t);
miny = std::min(miny,it->y);
minx = std::min(minx,it->x);
maxy = std::max(maxy,it->y);
maxx = std::max(maxx,it->x);
}
mean = mean / ((float)component.size());
for (std::vector<float>::const_iterator it = temp.begin(); it != temp.end(); it++) {
variance += (*it - mean) * (*it - mean);
}
variance = variance / ((float)component.size());
std::sort(temp.begin(),temp.end());
median = temp[temp.size()/2];
}
void filterComponents(IplImage * SWTImage,
std::vector<std::vector<Point2d> > & components,
std::vector<std::vector<Point2d> > & validComponents,
std::vector<Point2dFloat> & compCenters,
std::vector<float> & compMedians,
std::vector<Point2d> & compDimensions,
std::vector<std::pair<Point2d,Point2d> > & compBB )
{
validComponents.reserve(components.size());
compCenters.reserve(components.size());
compMedians.reserve(components.size());
compDimensions.reserve(components.size());
// bounding boxes
compBB.reserve(components.size());
for (std::vector<std::vector<Point2d> >::iterator it = components.begin(); it != components.end();it++) {
// compute the stroke width mean, variance, median
float mean, variance, median;
int minx, miny, maxx, maxy;
componentStats(SWTImage, (*it), mean, variance, median, minx, miny, maxx, maxy);
// check if variance is less than half the mean
if (variance > 0.5 * mean) {
continue;
}
float length = (float)(maxx-minx+1);
float width = (float)(maxy-miny+1);
// check font height
if (width > 300) {
continue;
}
float area = length * width;
float rminx = (float)minx;
float rmaxx = (float)maxx;
float rminy = (float)miny;
float rmaxy = (float)maxy;
// compute the rotated bounding box
float increment = 1./36.;
for (float theta = increment * PI; theta<PI/2.0; theta += increment * PI) {
float xmin,xmax,ymin,ymax,xtemp,ytemp,ltemp,wtemp;
xmin = 1000000;
ymin = 1000000;
xmax = 0;
ymax = 0;
for (unsigned int i = 0; i < (*it).size(); i++) {
xtemp = (*it)[i].x * cos(theta) + (*it)[i].y * -sin(theta);
ytemp = (*it)[i].x * sin(theta) + (*it)[i].y * cos(theta);
xmin = std::min(xtemp,xmin);
xmax = std::max(xtemp,xmax);
ymin = std::min(ytemp,ymin);
ymax = std::max(ytemp,ymax);
}
ltemp = xmax - xmin + 1;
wtemp = ymax - ymin + 1;
if (ltemp*wtemp < area) {
area = ltemp*wtemp;
length = ltemp;
width = wtemp;
}
}
// check if the aspect ratio is between 1/10 and 10
if (length/width < 1./10. || length/width > 10.) {
continue;
}
// compute the diameter TODO finish
// compute dense representation of component
std::vector <std::vector<float> > denseRepr;
denseRepr.reserve(maxx-minx+1);
for (int i = 0; i < maxx-minx+1; i++) {
std::vector<float> tmp;
tmp.reserve(maxy-miny+1);
denseRepr.push_back(tmp);
for (int j = 0; j < maxy-miny+1; j++) {\
denseRepr[i].push_back(0);
}
}
for (std::vector<Point2d>::iterator pit = it->begin(); pit != it->end(); pit++) {
(denseRepr[pit->x - minx])[pit->y - miny] = 1;
}
// create graph representing components
const int num_nodes = it->size();
/*
E edges[] = { E(0,2),
E(1,1), E(1,3), E(1,4),
E(2,1), E(2,3),
E(3,4),
E(4,0), E(4,1) };
Graph G(edges + sizeof(edges) / sizeof(E), weights, num_nodes);
*/
Point2dFloat center;
center.x = ((float)(maxx+minx))/2.0;
center.y = ((float)(maxy+miny))/2.0;
Point2d dimensions;
dimensions.x = maxx - minx + 1;
dimensions.y = maxy - miny + 1;
Point2d bb1;
bb1.x = minx;
bb1.y = miny;
Point2d bb2;
bb2.x = maxx;
bb2.y = maxy;
std::pair<Point2d, Point2d> pair(bb1,bb2);
compBB.push_back(pair);
compDimensions.push_back(dimensions);
compMedians.push_back(median);
compCenters.push_back(center);
validComponents.push_back(*it);
}
std::vector<std::vector<Point2d > > tempComp;
std::vector<Point2d > tempDim;
std::vector<float > tempMed;
std::vector<Point2dFloat > tempCenters;
std::vector<std::pair<Point2d,Point2d> > tempBB;
tempComp.reserve(validComponents.size());
tempCenters.reserve(validComponents.size());
tempDim.reserve(validComponents.size());
tempMed.reserve(validComponents.size());
tempBB.reserve(validComponents.size());
for (unsigned int i = 0; i < validComponents.size(); i++) {
int count = 0;
for (unsigned int j = 0; j < validComponents.size(); j++) {
if (i != j) {
if (compBB[i].first.x <= compCenters[j].x && compBB[i].second.x >= compCenters[j].x &&
compBB[i].first.y <= compCenters[j].y && compBB[i].second.y >= compCenters[j].y) {
count++;
}
}
}
if (count < 2) {
tempComp.push_back(validComponents[i]);
tempCenters.push_back(compCenters[i]);
tempMed.push_back(compMedians[i]);
tempDim.push_back(compDimensions[i]);
tempBB.push_back(compBB[i]);
}
}
validComponents = tempComp;
compDimensions = tempDim;
compMedians = tempMed;
compCenters = tempCenters;
compBB = tempBB;
compDimensions.reserve(tempComp.size());
compMedians.reserve(tempComp.size());
compCenters.reserve(tempComp.size());
validComponents.reserve(tempComp.size());
compBB.reserve(tempComp.size());
std::cout << "After filtering " << validComponents.size() << " components" << std::endl;
}
bool sharesOneEnd( Chain c0, Chain c1) {
if (c0.p == c1.p || c0.p == c1.q || c0.q == c1.q || c0.q == c1.p) {
return true;
}
else {
return false;
}
}
bool chainSortDist (const Chain &lhs, const Chain &rhs) {
return lhs.dist < rhs.dist;
}
bool chainSortLength (const Chain &lhs, const Chain &rhs) {
return lhs.components.size() > rhs.components.size();
}
std::vector<Chain> makeChains( IplImage * colorImage,
std::vector<std::vector<Point2d> > & components,
std::vector<Point2dFloat> & compCenters,
std::vector<float> & compMedians,
std::vector<Point2d> & compDimensions,
std::vector<std::pair<Point2d,Point2d> > & compBB) {
assert (compCenters.size() == components.size());
// make vector of color averages
std::vector<Point3dFloat> colorAverages;
colorAverages.reserve(components.size());
for (std::vector<std::vector<Point2d> >::iterator it = components.begin(); it != components.end();it++) {
Point3dFloat mean;
mean.x = 0;
mean.y = 0;
mean.z = 0;
int num_points = 0;
for (std::vector<Point2d>::iterator pit = it->begin(); pit != it->end(); pit++) {
mean.x += (float) CV_IMAGE_ELEM (colorImage, unsigned char, pit->y, (pit->x)*3 );
mean.y += (float) CV_IMAGE_ELEM (colorImage, unsigned char, pit->y, (pit->x)*3+1 );
mean.z += (float) CV_IMAGE_ELEM (colorImage, unsigned char, pit->y, (pit->x)*3+2 );
num_points++;
}
mean.x = mean.x / ((float)num_points);
mean.y = mean.y / ((float)num_points);
mean.z = mean.z / ((float)num_points);
colorAverages.push_back(mean);
}
// form all eligible pairs and calculate the direction of each
std::vector<Chain> chains;
for ( unsigned int i = 0; i < components.size(); i++ ) {
for ( unsigned int j = i + 1; j < components.size(); j++ ) {
// TODO add color metric
if ( (compMedians[i]/compMedians[j] <= 2.0 || compMedians[j]/compMedians[i] <= 2.0) &&
(compDimensions[i].y/compDimensions[j].y <= 2.0 || compDimensions[j].y/compDimensions[i].y <= 2.0)) {
float dist = (compCenters[i].x - compCenters[j].x) * (compCenters[i].x - compCenters[j].x) +
(compCenters[i].y - compCenters[j].y) * (compCenters[i].y - compCenters[j].y);
float colorDist = (colorAverages[i].x - colorAverages[j].x) * (colorAverages[i].x - colorAverages[j].x) +
(colorAverages[i].y - colorAverages[j].y) * (colorAverages[i].y - colorAverages[j].y) +
(colorAverages[i].z - colorAverages[j].z) * (colorAverages[i].z - colorAverages[j].z);
if (dist < 9*(float)(std::max(std::min(compDimensions[i].x,compDimensions[i].y),std::min(compDimensions[j].x,compDimensions[j].y)))
*(float)(std::max(std::min(compDimensions[i].x,compDimensions[i].y),std::min(compDimensions[j].x,compDimensions[j].y)))
&& colorDist < 1600) {
Chain c;
c.p = i;
c.q = j;
std::vector<int> comps;
comps.push_back(c.p);
comps.push_back(c.q);
c.components = comps;
c.dist = dist;
float d_x = (compCenters[i].x - compCenters[j].x);
float d_y = (compCenters[i].y - compCenters[j].y);
/*
float d_x = (compBB[i].first.x - compBB[j].second.x);
float d_y = (compBB[i].second.y - compBB[j].second.y);
*/
float mag = sqrt(d_x*d_x + d_y*d_y);
d_x = d_x / mag;
d_y = d_y / mag;
Point2dFloat dir;
dir.x = d_x;
dir.y = d_y;
c.direction = dir;
chains.push_back(c);
/*std::cerr << c.p << " " << c.q << std::endl;
std::cerr << c.direction.x << " " << c.direction.y << std::endl;
std::cerr << compCenters[c.p].x << " " << compCenters[c.p].y << std::endl;
std::cerr << compCenters[c.q].x << " " << compCenters[c.q].y << std::endl;
std::cerr << std::endl;
std::cerr << colorDist << std::endl; */
}
}
}
}
std::cout << chains.size() << " eligible pairs" << std::endl;
std::sort(chains.begin(), chains.end(), &chainSortDist);
const float strictness = PI/6.0;
//merge chains
int merges = 1;
while (merges > 0) {
for (unsigned int i = 0; i < chains.size(); i++) {
chains[i].merged = false;
}
merges = 0;
std::vector<Chain> newchains;
for (unsigned int i = 0; i < chains.size(); i++) {
for (unsigned int j = 0; j < chains.size(); j++) {
if (i != j) {
if (!chains[i].merged && !chains[j].merged && sharesOneEnd(chains[i],chains[j])) {