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Passing argument to a function

Hello experts!

Have a look at my source code.

Two questions if I may:

1. How can I pass argument to this function when debugging using VC++
2. How can I pass argument to this function when running using console?

Thank you!

panJames

#include <cv.h>
#include <highgui.h>
#include <math.h>

using namespace cv;

int main(int argc, char** argv)
{
    Mat src, dst, color_dst;
    if( argc != 2 || !(src=imread(argv[1], 0)).data)
        return -1;

    Canny( src, dst, 50, 200, 3 );
    cvtColor( dst, color_dst, CV_GRAY2BGR );


    vector<Vec4i> lines;
    HoughLinesP( dst, lines, 1, CV_PI/180, 80, 30, 10 );
    for( size_t i = 0; i < lines.size(); i++ )
    {
        line( color_dst, Point(lines[i][0], lines[i][1]),
            Point(lines[i][2], lines[i][3]), Scalar(0,0,255), 3, 8 );
    }

    namedWindow( "Source", 1 );
    imshow( "Source", src );

    namedWindow( "Detected Lines", 1 );
    imshow( "Detected Lines", color_dst );

    waitKey(0);
    return 0;

}

Open in new window

#include <cv.h>
#include <highgui.h>
#include <math.h>

using namespace cv;

int main(int argc, char** argv)
{
    Mat src, dst, color_dst;
    if( argc != 2 || !(src=imread(argv[1], 0)).data)
        return -1;

    Canny( src, dst, 50, 200, 3 );
    cvtColor( dst, color_dst, CV_GRAY2BGR );


    vector<Vec4i> lines;
    HoughLinesP( dst, lines, 1, CV_PI/180, 80, 30, 10 );
    for( size_t i = 0; i < lines.size(); i++ )
    {
        line( color_dst, Point(lines[i][0], lines[i][1]),
            Point(lines[i][2], lines[i][3]), Scalar(0,0,255), 3, 8 );
    }

    namedWindow( "Source", 1 );
    imshow( "Source", src );

    namedWindow( "Detected Lines", 1 );
    imshow( "Detected Lines", color_dst );

    waitKey(0);
    return 0;

}

Open in new window

jkr

Well what kind of argument do you want to pass to which function in the above?

Infinity08

Both programs seem to accept an image filename is the one and only argument, so you could call it like this eg. :

my_application.exe my_image.ext

panJames

ASKER

According to website I took example from:

http://opencv.willowgarage.com/documentation/cpp/feature_detection.html?highlight=hough#HoughLinesP

it should be file name.

/* This is a standalone program. Pass an image name as a first parameter
of the program. */

For me it looks like integer should be first...

panJames

Infinity08

>> For me it looks like integer should be first...

argv[0] is the executable name
argv[1] is the first parameter

argc contains the amount of items in the argv array (including the executable name)

So the (argc != 2) check makes sure that argc is equal to 2 (the executable name plus one parameter), and the one parameter is then passed to the imread function.

SOLUTION

jkr

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panJames

ASKER

To Infinity08

I typed in console as you said:

my_application.exe my_image.ext

And it works fine!

Two questions though:

1. In my main function

int main(int argc, char** argv)

first argument argc is integer, why don't I actually pass it?

2. How can I pass my arguments to main in VC++ for checking how it works during debuggin?

panJames

ASKER CERTIFIED SOLUTION

Infinity08

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jkr

You can enter your arguments in the Project Settings, category 'Debug'.