/*
* Copyright (c) 2015 OpenALPR Technology, Inc.
* Open source Automated License Plate Recognition [http://www.openalpr.com]
*
* This file is part of OpenALPR.
*
* OpenALPR is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License
* version 3 as published by the Free Software Foundation
*
* This program 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 Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see .
*/
#include "platemask.h"
using namespace std;
using namespace cv;
namespace alpr
{
PlateMask::PlateMask(PipelineData* pipeline_data) {
this->pipeline_data = pipeline_data;
this->hasPlateMask = false;
}
PlateMask::~PlateMask() {
}
cv::Mat PlateMask::getMask() {
return this->plateMask;
}
// Tries to find a rectangular area surrounding most of the characters. Not required
// but helpful when determining the plate edges
void PlateMask::findOuterBoxMask( vector contours )
{
double min_parent_area = pipeline_data->config->templateHeightPx * pipeline_data->config->templateWidthPx * 0.10; // Needs to be at least 10% of the plate area to be considered.
int winningIndex = -1;
int winningParentId = -1;
int bestCharCount = 0;
double lowestArea = 99999999999999;
if (pipeline_data->config->debugCharAnalysis)
cout << "CharacterAnalysis::findOuterBoxMask" << endl;
for (unsigned int imgIndex = 0; imgIndex < contours.size(); imgIndex++)
{
//vector charContours = filter(thresholds[imgIndex], allContours[imgIndex], allHierarchy[imgIndex]);
int charsRecognized = 0;
int parentId = -1;
bool hasParent = false;
for (unsigned int i = 0; i < contours[imgIndex].goodIndices.size(); i++)
{
if (contours[imgIndex].goodIndices[i]) charsRecognized++;
if (contours[imgIndex].goodIndices[i] && contours[imgIndex].hierarchy[i][3] != -1)
{
parentId = contours[imgIndex].hierarchy[i][3];
hasParent = true;
}
}
if (charsRecognized == 0)
continue;
if (hasParent)
{
double boxArea = contourArea(contours[imgIndex].contours[parentId]);
if (boxArea < min_parent_area)
continue;
if ((charsRecognized > bestCharCount) ||
(charsRecognized == bestCharCount && boxArea < lowestArea))
//(boxArea < lowestArea)
{
bestCharCount = charsRecognized;
winningIndex = imgIndex;
winningParentId = parentId;
lowestArea = boxArea;
}
}
}
if (pipeline_data->config->debugCharAnalysis)
cout << "Winning image index (findOuterBoxMask) is: " << winningIndex << endl;
if (winningIndex != -1 && bestCharCount >= 3)
{
Mat mask = Mat::zeros(pipeline_data->thresholds[winningIndex].size(), CV_8U);
// get rid of the outline by drawing a 1 pixel width black line
drawContours(mask, contours[winningIndex].contours,
winningParentId, // draw this contour
cv::Scalar(255,255,255), // in
CV_FILLED,
8,
contours[winningIndex].hierarchy,
0
);
// Morph Open the mask to get rid of any little connectors to non-plate portions
int morph_elem = 2;
int morph_size = 3;
Mat element = getStructuringElement( morph_elem, Size( 2*morph_size + 1, 2*morph_size+1 ), Point( morph_size, morph_size ) );
//morphologyEx( mask, mask, MORPH_CLOSE, element );
morphologyEx( mask, mask, MORPH_OPEN, element );
//morph_size = 1;
//element = getStructuringElement( morph_elem, Size( 2*morph_size + 1, 2*morph_size+1 ), Point( morph_size, morph_size ) );
//dilate(mask, mask, element);
// Drawing the edge black effectively erodes the image. This may clip off some extra junk from the edges.
// We'll want to do the contour again and find the larges one so that we remove the clipped portion.
vector > contoursSecondRound;
findContours(mask, contoursSecondRound, CV_RETR_EXTERNAL, CV_CHAIN_APPROX_SIMPLE);
int biggestContourIndex = -1;
double largestArea = 0;
for (unsigned int c = 0; c < contoursSecondRound.size(); c++)
{
double area = contourArea(contoursSecondRound[c]);
if (area > largestArea)
{
biggestContourIndex = c;
largestArea = area;
}
}
if (biggestContourIndex != -1)
{
mask = Mat::zeros(pipeline_data->thresholds[winningIndex].size(), CV_8U);
vector smoothedMaskPoints;
approxPolyDP(contoursSecondRound[biggestContourIndex], smoothedMaskPoints, 2, true);
vector > tempvec;
tempvec.push_back(smoothedMaskPoints);
//fillPoly(mask, smoothedMaskPoints.data(), smoothedMaskPoints, Scalar(255,255,255));
drawContours(mask, tempvec,
0, // draw this contour
cv::Scalar(255,255,255), // in
CV_FILLED,
8,
contours[winningIndex].hierarchy,
0
);
}
if (pipeline_data->config->debugCharAnalysis)
{
vector debugImgs;
Mat debugImgMasked = Mat::zeros(pipeline_data->thresholds[winningIndex].size(), CV_8U);
pipeline_data->thresholds[winningIndex].copyTo(debugImgMasked, mask);
debugImgs.push_back(mask);
debugImgs.push_back(pipeline_data->thresholds[winningIndex]);
debugImgs.push_back(debugImgMasked);
Mat dashboard = drawImageDashboard(debugImgs, CV_8U, 1);
displayImage(pipeline_data->config, "Winning outer box", dashboard);
}
hasPlateMask = true;
this->plateMask = mask;
} else {
hasPlateMask = false;
Mat fullMask = Mat::zeros(pipeline_data->thresholds[0].size(), CV_8U);
bitwise_not(fullMask, fullMask);
this->plateMask = fullMask;
}
}
}