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asked 2016-09-03 11:25:35 -0600

Tharindu J gravatar image

need help to change this code to live web cam streaming

Hello I followed this video(https://www.youtube.com/watch?v=Y3ac5rFMNZ0) and it was perfectly worked.. but when i change code for web cam capturing it only gets static image.. then i commented lines 54 - 58, lines 177 - 183,(as mentioning in video comment) but still not working... Anyone knows to solve this.I need to apply this to my conveyor design undergraduate project to count objects.. Below shows my edited code(only main cpp)....

// main.cpp

include<opencv2 core="" core.hpp="">

include<opencv2 highgui="" highgui.hpp="">

include<opencv2 imgproc="" imgproc.hpp="">

include<iostream>

include<conio.h> // it may be necessary to change or remove this line if not using Windows

include "Blob.h"

define SHOW_STEPS // un-comment or comment this line to show steps or not

// global variables /////////////////////////////////////////////////////////////////////////////// const cv::Scalar SCALAR_BLACK = cv::Scalar(0.0, 0.0, 0.0); const cv::Scalar SCALAR_WHITE = cv::Scalar(255.0, 255.0, 255.0); const cv::Scalar SCALAR_YELLOW = cv::Scalar(0.0, 255.0, 255.0); const cv::Scalar SCALAR_GREEN = cv::Scalar(0.0, 200.0, 0.0); const cv::Scalar SCALAR_RED = cv::Scalar(0.0, 0.0, 255.0);

// function prototypes //////////////////////////////////////////////////////////////////////////// void matchCurrentFrameBlobsToExistingBlobs(std::vector<blob> &existingBlobs, std::vector<blob> &currentFrameBlobs); void addBlobToExistingBlobs(Blob &currentFrameBlob, std::vector<blob> &existingBlobs, int &intIndex); void addNewBlob(Blob &currentFrameBlob, std::vector<blob> &existingBlobs); double distanceBetweenPoints(cv::Point point1, cv::Point point2); void drawAndShowContours(cv::Size imageSize, std::vector<std::vector<cv::point> > contours, std::string strImageName); void drawAndShowContours(cv::Size imageSize, std::vector<blob> blobs, std::string strImageName); bool checkIfBlobsCrossedTheLine(std::vector<blob> &blobs, int &intHorizontalLinePosition, int &carCount); void drawBlobInfoOnImage(std::vector<blob> &blobs, cv::Mat &imgFrame2Copy); void drawCarCountOnImage(int &carCount, cv::Mat &imgFrame2Copy);

/////////////////////////////////////////////////////////////////////////////////////////////////// int main(void) {

cv::VideoCapture capVideo;

cv::Mat imgFrame1;
cv::Mat imgFrame2;

std::vector<Blob> blobs;

cv::Point crossingLine[2];

int carCount = 0;

capVideo.open(0);

if (!capVideo.isOpened()) {                                                 // if unable to open video file
    std::cout << "error reading video file" << std::endl << std::endl;      // show error message
    _getch();                   // it may be necessary to change or remove this line if not using Windows
    return(0);                                                              // and exit program
}

/*if (capVideo.get(CV_CAP_PROP_FRAME_COUNT) < 2) {
    std::cout << "error: video file must have at least two frames";
    _getch();                   // it may be necessary to change or remove this line if not using Windows
    return(0);
}*/

capVideo.read(imgFrame1);
capVideo.read(imgFrame2);

int intHorizontalLinePosition = (int)std::round((double)imgFrame1.rows * 0.35);

crossingLine[0].x = 0;
crossingLine[0].y = intHorizontalLinePosition;

crossingLine[1].x = imgFrame1.cols - 1;
crossingLine[1].y = intHorizontalLinePosition;

char chCheckForEscKey = 0;

bool blnFirstFrame = true;

int frameCount = 2;

while (capVideo.isOpened() && chCheckForEscKey != 27) {

    std::vector<Blob> currentFrameBlobs;

    cv::Mat imgFrame1Copy = imgFrame1.clone();
    cv::Mat imgFrame2Copy = imgFrame2.clone();

    cv::Mat imgDifference;
    cv::Mat imgThresh;

    cv::cvtColor(imgFrame1Copy, imgFrame1Copy, CV_BGR2GRAY);
    cv::cvtColor(imgFrame2Copy, imgFrame2Copy, CV_BGR2GRAY);

    cv::GaussianBlur(imgFrame1Copy, imgFrame1Copy, cv::Size(5, 5), 0);
    cv::GaussianBlur(imgFrame2Copy, imgFrame2Copy, cv::Size(5, 5), 0);

    cv::absdiff(imgFrame1Copy, imgFrame2Copy, imgDifference);

    cv::threshold(imgDifference, imgThresh, 30, 255.0, CV_THRESH_BINARY);

    cv::imshow("imgThresh", imgThresh);

    cv::Mat structuringElement3x3 = cv::getStructuringElement(cv::MORPH_RECT, cv::Size(3, 3));
    cv::Mat structuringElement5x5 = cv::getStructuringElement(cv::MORPH_RECT, cv::Size(5, 5));
    cv::Mat structuringElement7x7 = cv::getStructuringElement(cv::MORPH_RECT, cv::Size(7, 7));
    cv::Mat structuringElement15x15 = cv::getStructuringElement(cv::MORPH_RECT, cv::Size(15, 15));

    for (unsigned int i = 0; i < 2; i++) {
        cv::dilate(imgThresh, imgThresh, structuringElement5x5);
        cv::dilate(imgThresh, imgThresh, structuringElement5x5);
        cv::erode(imgThresh, imgThresh, structuringElement5x5);
    }

    cv::Mat imgThreshCopy = imgThresh.clone();

    std::vector<std::vector<cv::Point> > contours;

    cv::findContours(imgThreshCopy, contours, cv::RETR_EXTERNAL, cv::CHAIN_APPROX_SIMPLE);

    drawAndShowContours(imgThresh.size(), contours, "imgContours");

    std::vector<std::vector<cv::Point> > convexHulls(contours.size());

    for (unsigned int i = 0; i < contours.size(); i++) {
        cv::convexHull(contours[i], convexHulls[i]);
    }

    drawAndShowContours(imgThresh.size(), convexHulls, "imgConvexHulls");

    for (auto &convexHull : convexHulls) {
        Blob possibleBlob(convexHull);

        if (possibleBlob.currentBoundingRect.area() > 400 &&
            possibleBlob.dblCurrentAspectRatio > 0.2 &&
            possibleBlob.dblCurrentAspectRatio < 4.0 &&
            possibleBlob.currentBoundingRect.width > 30 &&
            possibleBlob.currentBoundingRect.height > 30 &&
            possibleBlob.dblCurrentDiagonalSize > 60.0 &&
            (cv::contourArea(possibleBlob.currentContour) / (double)possibleBlob.currentBoundingRect.area()) > 0.50) {
            currentFrameBlobs.push_back(possibleBlob);
        }
    }

    drawAndShowContours(imgThresh.size(), currentFrameBlobs, "imgCurrentFrameBlobs");

    if (blnFirstFrame == true) {
        for (auto &currentFrameBlob : currentFrameBlobs) {
            blobs.push_back(currentFrameBlob);
        }
    }
    else {
        matchCurrentFrameBlobsToExistingBlobs(blobs, currentFrameBlobs);
    }

    drawAndShowContours(imgThresh.size(), blobs, "imgBlobs");

    imgFrame2Copy = imgFrame2.clone();          // get another copy of frame 2 since we changed the previous frame 2 copy in the processing above

    drawBlobInfoOnImage(blobs, imgFrame2Copy);

    bool blnAtLeastOneBlobCrossedTheLine = checkIfBlobsCrossedTheLine(blobs, intHorizontalLinePosition, carCount);

    if (blnAtLeastOneBlobCrossedTheLine == true) {
        cv::line(imgFrame2Copy, crossingLine[0], crossingLine[1], SCALAR_GREEN, 2);
    }
    else {
        cv::line(imgFrame2Copy, crossingLine[0], crossingLine[1], SCALAR_RED, 2);
    }

    drawCarCountOnImage(carCount, imgFrame2Copy);

    cv::imshow("imgFrame2Copy", imgFrame2Copy);

    //cv::waitKey(0);                 // uncomment this line to go frame by frame for debugging

    // now we prepare for the next iteration

    currentFrameBlobs.clear();

    imgFrame1 = imgFrame2.clone();           // move frame 1 up to where frame 2 is

    /*if ((capVideo.get(CV_CAP_PROP_POS_FRAMES) + 1) < capVideo.get(CV_CAP_PROP_FRAME_COUNT)) {
        capVideo.read(imgFrame2);
    }
    else {
        std::cout << "end of video\n";
        break;
    } */

    blnFirstFrame = false;
    frameCount++;
    chCheckForEscKey = cv::waitKey(1);
}

if (chCheckForEscKey != 27) {               // if the user did not press esc (i.e. we reached the end of the video)
    cv::waitKey(0);                         // hold the windows open to allow the "end of video" message to show
}
// note that if the user did press esc, we don't need to hold the windows open, we can simply let the program end which will close the windows

return(0);

}

/////////////////////////////////////////////////////////////////////////////////////////////////// void matchCurrentFrameBlobsToExistingBlobs(std::vector<blob> &existingBlobs, std::vector<blob> &currentFrameBlobs) {

for (auto &existingBlob : existingBlobs) {

    existingBlob.blnCurrentMatchFoundOrNewBlob = false;

    existingBlob.predictNextPosition();
}

for (auto &currentFrameBlob : currentFrameBlobs) {

    int intIndexOfLeastDistance = 0;
    double dblLeastDistance = 100000.0;

    for (unsigned int i = 0; i < existingBlobs.size(); i++) {

        if (existingBlobs[i].blnStillBeingTracked == true) {

            double dblDistance = distanceBetweenPoints(currentFrameBlob.centerPositions.back(), existingBlobs[i].predictedNextPosition);

            if (dblDistance < dblLeastDistance) {
                dblLeastDistance = dblDistance;
                intIndexOfLeastDistance = i;
            }
        }
    }

    if (dblLeastDistance < currentFrameBlob.dblCurrentDiagonalSize * 0.5) {
        addBlobToExistingBlobs(currentFrameBlob, existingBlobs, intIndexOfLeastDistance);
    }
    else {
        addNewBlob(currentFrameBlob, existingBlobs);
    }

}

for (auto &existingBlob : existingBlobs) {

    if (existingBlob.blnCurrentMatchFoundOrNewBlob == false) {
        existingBlob.intNumOfConsecutiveFramesWithoutAMatch++;
    }

    if (existingBlob.intNumOfConsecutiveFramesWithoutAMatch >= 5) {
        existingBlob.blnStillBeingTracked = false;
    }

}

}

/////////////////////////////////////////////////////////////////////////////////////////////////// void addBlobToExistingBlobs(Blob &currentFrameBlob, std::vector<blob> &existingBlobs, int &intIndex) {

existingBlobs[intIndex].currentContour = currentFrameBlob.currentContour;
existingBlobs[intIndex].currentBoundingRect = currentFrameBlob.currentBoundingRect;

existingBlobs[intIndex].centerPositions.push_back(currentFrameBlob.centerPositions.back());

existingBlobs[intIndex].dblCurrentDiagonalSize = currentFrameBlob.dblCurrentDiagonalSize;
existingBlobs[intIndex].dblCurrentAspectRatio = currentFrameBlob.dblCurrentAspectRatio;

existingBlobs[intIndex].blnStillBeingTracked = true;
existingBlobs[intIndex].blnCurrentMatchFoundOrNewBlob = true;

}

/////////////////////////////////////////////////////////////////////////////////////////////////// void addNewBlob(Blob &currentFrameBlob, std::vector<blob> &existingBlobs) {

currentFrameBlob.blnCurrentMatchFoundOrNewBlob = true;

existingBlobs.push_back(currentFrameBlob);

}

/////////////////////////////////////////////////////////////////////////////////////////////////// double distanceBetweenPoints(cv::Point point1, cv::Point point2) {

int intX = abs(point1.x - point2.x);
int intY = abs(point1.y - point2.y);

return(sqrt(pow(intX, 2) + pow(intY, 2)));

}

/////////////////////////////////////////////////////////////////////////////////////////////////// void drawAndShowContours(cv::Size imageSize, std::vector<std::vector<cv::point> > contours, std::string strImageName) { cv::Mat image(imageSize, CV_8UC3, SCALAR_BLACK);

cv::drawContours(image, contours, -1, SCALAR_WHITE, -1);

cv::imshow(strImageName, image);

}

/////////////////////////////////////////////////////////////////////////////////////////////////// void drawAndShowContours(cv::Size imageSize, std::vector<blob> blobs, std::string strImageName) {

cv::Mat image(imageSize, CV_8UC3, SCALAR_BLACK);

std::vector<std::vector<cv::Point> > contours;

for (auto &blob : blobs) {
    if (blob.blnStillBeingTracked == true) {
        contours.push_back(blob.currentContour);
    }
}

cv::drawContours(image, contours, -1, SCALAR_WHITE, -1);

cv::imshow(strImageName, image);

}

/////////////////////////////////////////////////////////////////////////////////////////////////// bool checkIfBlobsCrossedTheLine(std::vector<blob> &blobs, int &intHorizontalLinePosition, int &carCount) { bool blnAtLeastOneBlobCrossedTheLine = false;

for (auto blob : blobs) {

    if (blob.blnStillBeingTracked == true && blob.centerPositions.size() >= 2) {
        int prevFrameIndex = (int)blob.centerPositions.size() - 2;
        int currFrameIndex = (int)blob.centerPositions.size() - 1;

        if (blob.centerPositions[prevFrameIndex].y > intHorizontalLinePosition && blob.centerPositions[currFrameIndex].y <= intHorizontalLinePosition) {
            carCount++;
            blnAtLeastOneBlobCrossedTheLine = true;
        }
    }

}

return blnAtLeastOneBlobCrossedTheLine;

}

/////////////////////////////////////////////////////////////////////////////////////////////////// void drawBlobInfoOnImage(std::vector<blob> &blobs, cv::Mat &imgFrame2Copy) {

for (unsigned int i = 0; i < blobs.size(); i++) {

    if (blobs[i].blnStillBeingTracked == true) {
        cv::rectangle(imgFrame2Copy, blobs[i].currentBoundingRect, SCALAR_RED, 2);

        int intFontFace = CV_FONT_HERSHEY_SIMPLEX;
        double dblFontScale = blobs[i].dblCurrentDiagonalSize / 60.0;
        int intFontThickness = (int)std::round(dblFontScale * 1.0);

        cv::putText(imgFrame2Copy, std::to_string(i), blobs[i].centerPositions.back(), intFontFace, dblFontScale, SCALAR_GREEN, intFontThickness);
    }
}

}

/////////////////////////////////////////////////////////////////////////////////////////////////// void drawCarCountOnImage(int &carCount, cv::Mat &imgFrame2Copy) {

int intFontFace = CV_FONT_HERSHEY_SIMPLEX;
double dblFontScale = (imgFrame2Copy.rows * imgFrame2Copy.cols) / 300000.0;
int intFontThickness = (int)std::round(dblFontScale * 1.5);

cv::Size textSize = cv::getTextSize(std::to_string(carCount), intFontFace, dblFontScale, intFontThickness, 0);

cv::Point ptTextBottomLeftPosition;

ptTextBottomLeftPosition.x = imgFrame2Copy.cols - 1 - (int)((double)textSize.width * 1.25);
ptTextBottomLeftPosition.y = (int)((double)textSize.height * 1.25);

cv::putText(imgFrame2Copy, std::to_string(carCount), ptTextBottomLeftPosition, intFontFace, dblFontScale, SCALAR_GREEN, intFontThickness);

}

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