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I am trying to find the rectangular regions from the image , but i am not getting any good result

Below the code for finding square :

void find_squares(Mat& image, vector<vector<Point> >& squares)
{
    // blur will enhance edge detection
    Mat blurred(image);
    medianBlur(image, blurred, 5);

    Mat gray0(blurred.size(), CV_8U), gray;
    vector<vector<Point> > contours;

    // find squares in every color plane of the image
    for (int c = 0; c < 1; c++)
    {
        int ch[] = {c, 0};
        mixChannels(&blurred, 1, &gray0, 1, ch, 1);

        // try several threshold levels
        const int threshold_level = 2;
        for (int l = 0; l < threshold_level; l++)
        {
            // Use Canny instead of zero threshold level!
            // Canny helps to catch squares with gradient shading
            if (l == 0)
            {
                Canny(gray0, gray, 10, 20, 3); // 

                // Dilate helps to remove potential holes between edge segments
                dilate(gray, gray, Mat(), Point(-1,-1));
            }
            else
            {
                    gray = gray0 >= (l+1) * 255 / threshold_level;
            }

            // Find contours and store them in a list
            findContours(gray, contours, CV_RETR_LIST, CV_CHAIN_APPROX_SIMPLE);

            // Test contours
            vector<Point> approx;
            for (size_t i = 0; i < contours.size(); i++)
            {
                    // approximate contour with accuracy proportional
                    // to the contour perimeter
                    approxPolyDP(Mat(contours[i]), approx, arcLength(Mat(contours[i]), true)*0.02, true);

                    // Note: absolute value of an area is used because
                    // area may be positive or negative - in accordance with the
                    // contour orientation
                    if (approx.size() == 4 &&
                            fabs(contourArea(Mat(approx))) > 1000 &&
                            isContourConvex(Mat(approx)))
                    {
                            double maxCosine = 0;

                            for (int j = 2; j < 5; j++)
                            {
                                    double cosine = fabs(angle(approx[j%4], approx[j-2], approx[j-1]));
                                    maxCosine = MAX(maxCosine, cosine);
                            }

                            if (maxCosine < 0.3)
                                    squares.push_back(approx);
                    }
            }
        }
    }
}

and here is what i am doing in main :

vector<vector<Point> > squares;
find_squares(img, squares);
std::cout << "squares: " << squares.size() << std::endl;

draw_Squares(squares , img);

imwrite("area.png", img);
}

input image :

required output image :

I am trying to find the rectangular regions from the image , but i am not getting any good result and also getting results slow , due to visiting every channel

Below the code for finding square :

void find_squares(Mat& image, vector<vector<Point> >& squares)
{
    // blur will enhance edge detection
    Mat blurred(image);
    medianBlur(image, blurred, 5);

    Mat gray0(blurred.size(), CV_8U), gray;
    vector<vector<Point> > contours;

    // find squares in every color plane of the image
    //also tried one by one
    for (int c = 0; c < 1; c++)
    {
        int ch[] = {c, 0};
        mixChannels(&blurred, 1, &gray0, 1, ch, 1);

        // try tried several threshold levels
        const int threshold_level = 2;
        for (int l = 0; l < threshold_level; l++)
        {
            // Use Canny instead of zero threshold level!
            // Canny helps to catch squares with gradient shading
            if (l == 0)
            {
                Canny(gray0, gray, 10, 20, 3); // 

                // Dilate helps to remove potential holes between edge segments
                dilate(gray, gray, Mat(), Point(-1,-1));
            }
            else
            {
                    gray = gray0 >= (l+1) * 255 / threshold_level;
            }

            // Find contours and store them in a list
            findContours(gray, contours, CV_RETR_LIST, CV_CHAIN_APPROX_SIMPLE);

            // Test contours
            vector<Point> approx;
            for (size_t i = 0; i < contours.size(); i++)
            {
                    // approximate contour with accuracy proportional
                    // to the contour perimeter
                    approxPolyDP(Mat(contours[i]), approx, arcLength(Mat(contours[i]), true)*0.02, true);

                    // Note: absolute value of an area is used because
                    // area may be positive or negative - in accordance with the
                    // contour orientation
                    if (approx.size() == 4 &&
                            fabs(contourArea(Mat(approx))) > 1000 &&
                            isContourConvex(Mat(approx)))
                    {
                            double maxCosine = 0;

                            for (int j = 2; j < 5; j++)
                            {
                                    double cosine = fabs(angle(approx[j%4], approx[j-2], approx[j-1]));
                                    maxCosine = MAX(maxCosine, cosine);
                            }

                            if (maxCosine < 0.3)
                                    squares.push_back(approx);
                    }
            }
        }
    }
}

and here is what i am doing in main :

vector<vector<Point> > squares;
find_squares(img, squares);
std::cout << "squares: " << squares.size() << std::endl;

draw_Squares(squares , img);

imwrite("area.png", img);
}

input image :

required output image :

I am trying to find the rectangular regions from the image , but i am not getting any good result and also getting results slow , due to visiting every channel

Below the code for finding square :

void find_squares(Mat& image, vector<vector<Point> >& squares)
{
    // blur will enhance edge detection
    Mat blurred(image);
    medianBlur(image, blurred, 5);

    Mat gray0(blurred.size(), CV_8U), gray;
    vector<vector<Point> > contours;

    // find squares in every color plane of the image
    //also tried one by one
    for (int c = 0; c < 1; c++)
    {
        int ch[] = {c, 0};
        mixChannels(&blurred, 1, &gray0, 1, ch, 1);

        // tried several threshold levels
        const int threshold_level = 2;
        for (int l = 0; l < threshold_level; l++)
        {
            // Use Canny instead of zero threshold level!
            // Canny helps to catch squares with gradient shading
            if (l == 0)
            {
                Canny(gray0, gray, 10, 20, 3); // 

                // Dilate helps to remove potential holes between edge segments
                dilate(gray, gray, Mat(), Point(-1,-1));
            }
            else
            {
                    gray = gray0 >= (l+1) * 255 / threshold_level;
            }

            // Find contours and store them in a list
            findContours(gray, contours, CV_RETR_LIST, CV_CHAIN_APPROX_SIMPLE);

            // Test contours
            vector<Point> approx;
            for (size_t i = 0; i < contours.size(); i++)
            {
                    // approximate contour with accuracy proportional
                    // to the contour perimeter
                    approxPolyDP(Mat(contours[i]), approx, arcLength(Mat(contours[i]), true)*0.02, true);

                    // Note: absolute value of an area is used because
                    // area may be positive or negative - in accordance with the
                    // contour orientation
                    if (approx.size() == 4 &&
                            fabs(contourArea(Mat(approx))) > 1000 &&
                            isContourConvex(Mat(approx)))
                    {
                            double maxCosine = 0;

                            for (int j = 2; j < 5; j++)
                            {
                                    double cosine = fabs(angle(approx[j%4], approx[j-2], approx[j-1]));
                                    maxCosine = MAX(maxCosine, cosine);
                            }

                            if (maxCosine < 0.3)
                                    squares.push_back(approx);
                    }
            }
        }
    }
}

double angle( cv::Point pt1, cv::Point pt2, cv::Point pt0 ) {
    double dx1 = pt1.x - pt0.x;
    double dy1 = pt1.y - pt0.y;
    double dx2 = pt2.x - pt0.x;
    double dy2 = pt2.y - pt0.y;
    return (dx1*dx2 + dy1*dy2)/sqrt((dx1*dx1 + dy1*dy1)*(dx2*dx2 + dy2*dy2) + 1e-10);
}

and here is what i am doing in main :

vector<vector<Point> > squares;
find_squares(img, squares);
std::cout << "squares: " << squares.size() << std::endl;

draw_Squares(squares , img);

imwrite("area.png", img);
}

input image :

required output image :

I am trying to find the rectangular regions from the image ,its drawing the rectangle's but ***getting my specific need is not obtaining*** like i show below in pics , but i am not getting any good result and also getting results slow , due to visiting every channel

Below the code for finding square :

void find_squares(Mat& image, vector<vector<Point> >& squares)
{
    // blur will enhance edge detection
    Mat blurred(image);
    medianBlur(image, blurred, 5);

    Mat gray0(blurred.size(), CV_8U), gray;
    vector<vector<Point> > contours;

    // find squares in every color plane of the image
    //also tried one by one
    for (int c = 0; c < 1; c++)
    {
        int ch[] = {c, 0};
        mixChannels(&blurred, 1, &gray0, 1, ch, 1);

        // tried several threshold levels
        const int threshold_level = 2;
        for (int l = 0; l < threshold_level; l++)
        {
            // Use Canny instead of zero threshold level!
            // Canny helps to catch squares with gradient shading
            if (l == 0)
            {
                Canny(gray0, gray, 10, 20, 3); // 

                // Dilate helps to remove potential holes between edge segments
                dilate(gray, gray, Mat(), Point(-1,-1));
            }
            else
            {
                    gray = gray0 >= (l+1) * 255 / threshold_level;
            }

            // Find contours and store them in a list
            findContours(gray, contours, CV_RETR_LIST, CV_CHAIN_APPROX_SIMPLE);

            // Test contours
            vector<Point> approx;
            for (size_t i = 0; i < contours.size(); i++)
            {
                    // approximate contour with accuracy proportional
                    // to the contour perimeter
                    approxPolyDP(Mat(contours[i]), approx, arcLength(Mat(contours[i]), true)*0.02, true);

                    // Note: absolute value of an area is used because
                    // area may be positive or negative - in accordance with the
                    // contour orientation
                    if (approx.size() == 4 &&
                            fabs(contourArea(Mat(approx))) > 1000 &&
                            isContourConvex(Mat(approx)))
                    {
                            double maxCosine = 0;

                            for (int j = 2; j < 5; j++)
                            {
                                    double cosine = fabs(angle(approx[j%4], approx[j-2], approx[j-1]));
                                    maxCosine = MAX(maxCosine, cosine);
                            }

                            if (maxCosine < 0.3)
                                    squares.push_back(approx);
                    }
            }
        }
    }
}

double angle( cv::Point pt1, cv::Point pt2, cv::Point pt0 ) {
    double dx1 = pt1.x - pt0.x;
    double dy1 = pt1.y - pt0.y;
    double dx2 = pt2.x - pt0.x;
    double dy2 = pt2.y - pt0.y;
    return (dx1*dx2 + dy1*dy2)/sqrt((dx1*dx1 + dy1*dy1)*(dx2*dx2 + dy2*dy2) + 1e-10);
}

and here is what i am doing in main :

vector<vector<Point> > squares;
find_squares(img, squares);
std::cout << "squares: " << squares.size() << std::endl;

draw_Squares(squares , img);

imwrite("area.png", img);
}

input image :

required output image :

I am trying to find the rectangular regions from the image ,its drawing the rectangle's but ***getting my specific need is not obtaining*** like i show below in pics , and also getting results slow , due to visiting every channel

void find_squares(Mat& image, vector<vector<Point> >& squares)
{
    // blur will enhance edge detection
    Mat blurred(image);
    medianBlur(image, blurred, 5);

    Mat gray0(blurred.size(), CV_8U), gray;
    vector<vector<Point> > contours;

    // find squares in every color plane of the image
    //also tried one by one
    for (int c = 0; c < 1; c++)
    {
        int ch[] = {c, 0};
        mixChannels(&blurred, 1, &gray0, 1, ch, 1);

        // tried several threshold levels
        const int threshold_level = 2;
        for (int l = 0; l < threshold_level; l++)
        {
            // Use Canny instead of zero threshold level!
            // Canny helps to catch squares with gradient shading
            if (l == 0)
            {
                Canny(gray0, gray, 10, 20, 3); // 

                // Dilate helps to remove potential holes between edge segments
                dilate(gray, gray, Mat(), Point(-1,-1));
            }
            else
            {
                    gray = gray0 >= (l+1) * 255 / threshold_level;
            }

            // Find contours and store them in a list
            findContours(gray, contours, CV_RETR_LIST, CV_CHAIN_APPROX_SIMPLE);

            // Test contours
            vector<Point> approx;
            for (size_t i = 0; i < contours.size(); i++)
            {
                    // approximate contour with accuracy proportional
                    // to the contour perimeter
                    approxPolyDP(Mat(contours[i]), approx, arcLength(Mat(contours[i]), true)*0.02, true);

                    // Note: absolute value of an area is used because
                    // area may be positive or negative - in accordance with the
                    // contour orientation
                    if (approx.size() == 4 &&
                            fabs(contourArea(Mat(approx))) > 1000 &&
                            isContourConvex(Mat(approx)))
                    {
                            double maxCosine = 0;

                            for (int j = 2; j < 5; j++)
                            {
                                    double cosine = fabs(angle(approx[j%4], approx[j-2], approx[j-1]));
                                    maxCosine = MAX(maxCosine, cosine);
                            }

                            if (maxCosine < 0.3)
                                    squares.push_back(approx);
                    }
            }
        }
    }
}

double angle( cv::Point pt1, cv::Point pt2, cv::Point pt0 ) {
    double dx1 = pt1.x - pt0.x;
    double dy1 = pt1.y - pt0.y;
    double dx2 = pt2.x - pt0.x;
    double dy2 = pt2.y - pt0.y;
    return (dx1*dx2 + dy1*dy2)/sqrt((dx1*dx1 + dy1*dy1)*(dx2*dx2 + dy2*dy2) + 1e-10);
}

vector<vector<Point> > squares;
find_squares(img, squares);
std::cout << "squares: " << squares.size() << std::endl;

draw_Squares(squares , img);

imwrite("area.png", img);
}

I This is the code i am trying to find the rectangular regions from the using for display image ,its drawing the rectangle's using C interface in opencv

    IplImage * mSrcImg = cvLoadImage("C:\\test.jpg");
    IplImage * mOutImg;
    vector<IplImage*> b , g ,r;

    cvSplit(&mSrcImg , &b , &g , &r , NULL);
    cvEqualizeHist(&b, &b);
    cvEqualizeHist(&g, &g);
    cvEqualizeHist(&r, &r);

    cvMerge(&b, &g, &r, NULL, &mOutImg );

    cvShowImage("Image" , mOutImg);
    cvWaitKey();

but ***getting my specific need is not obtaining*** like i show below getting runtime error in pics , and also getting results slow , due to visiting every channelit.

This is the code i I am using for display image using C interface in opencvtrying to implement some function like below from Photoshop

    IplImage * mSrcImg = cvLoadImage("C:\\test.jpg");
    IplImage * mOutImg;
    vector<IplImage*> b , g ,r;

    cvSplit(&mSrcImg , &b , &g , &r , NULL);
    cvEqualizeHist(&b, &b);
    cvEqualizeHist(&g, &g);
    cvEqualizeHist(&r, &r);

    cvMerge(&b, &g, &r, NULL, &mOutImg );

    cvShowImage("Image" , mOutImg);
    cvWaitKey();

but For this I am trying to use Cubic interpolation and Catmull interpolation ( check both separately to compare the best result) , what i am not understanding is what impact these interpolation show on image and how we can get these points values where we clicked to set that curve ? and do we need to define the function these black points on the image separately ?

I am getting runtime error in it.help from these resources

Source 1

Source 2

Approx the same focus

I am trying want to implement some function count only the vignette area of this image , like below from Photoshopi have the image

For this How I am trying can count or iterate/pass through only in the area where vignette is applied and leave the other area ? I only want to use Cubic interpolation and Catmull interpolation ( check both separately to compare apply the best result) , what i am not understanding is what impact these interpolation show on image and how we can get these points values where we clicked to set that curve ? and do we need to define the function these black points algorithm on the image separately ?

area where vignette is applied , I am getting help from these resources

Source 1

Source 2

Approx tried it like give scalar to black color and extract area where it found the same focusblack color but its not working like not giving the results because color become lighter when coming towards centre of the image.

I want to count only the vignette area of this image , like i have the image Push_back is showing me error while using it with android

split(image,ch);
Mat ch0 = ch[0];
Mat ch1 = ch[1];
Mat ch2 = ch[2];

multiply(alpha, ch0, ch0);
multiply(alpha, ch1, ch1);
multiply(alpha, ch2, ch2);

vector<Mat> newVec;
newVec.push_back(ch0);
newVec.push_back(ch1);
newVec.push_back(ch2);

merge(newVec, image);

Error :

Invalid arguments ' Candidates are: void push_back(const cv::Mat &)

Push_back is showing me error while using it with android

split(image,ch);
Mat ch0 = ch[0];
Mat ch1 = ch[1];
Mat ch2 = ch[2];

multiply(alpha, ch0, ch0);
multiply(alpha, ch1, ch1);
multiply(alpha, ch2, ch2);

vector<Mat> newVec;
newVec.push_back(ch0);
newVec.push_back(ch1);
newVec.push_back(ch2);

merge(newVec, image);

Error :Error:

Invalid arguments ' Candidates are: void push_back(const cv::Mat &)

Vignette is not showing error

split(image,ch);
void Vignete(Mat& img1, Mat& img2, Mat& out)
{

        resize(img1, img1, img2.size());
        img1.convertTo(img1,CV_32FC4,1.0/255.0);
        img2.convertTo(img2, CV_32FC4, 1.0/255.0);
        vector<Mat> ch;
        Mat I1;
        split(img2,ch);
        Mat alpha1 = ch[3];
        Mat alpha = alpha1.clone();
            Mat ch0 = ch[0];
 Mat ch1 = ch[1];
Mat ch2         Mat ch_2 = ch[2];

multiply(alpha, ch0, ch0);
multiply(alpha, ch1, ch1);
multiply(alpha, ch2, ch2);

        Mat ch_3 = ch[3];
        cv::multiply(alpha,ch0,ch0);
        cv::multiply(alpha,ch1,ch1);
        cv::multiply(alpha,ch_2,ch_2);
            cv::multiply(alpha,ch_3,ch_3);
        vector<Mat> newVec;
 newVec.push_back(ch0);
 newVec.push_back(ch1);
newVec.push_back(ch2);

        newVec.push_back(ch_2);
        newVec.push_back(ch_3);
        merge(newVec, image);
I1);
        I1.convertTo(out, CV_8UC4, 255);
}

Invalid arguments ' Candidates are: void push_back(const cv::Mat &)