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

panJamesAsked:
Who is Participating?
I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

jkrCommented:
Well what kind of argument do you want to pass to which function in the above?
0
Infinity08Commented:
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
0
panJamesAuthor Commented:
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
0
Cloud Class® Course: Microsoft Windows 7 Basic

This introductory course to Windows 7 environment will teach you about working with the Windows operating system. You will learn about basic functions including start menu; the desktop; managing files, folders, and libraries.

Infinity08Commented:
>> 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.
0
jkrCommented:
Well, your call

HoughLinesP( dst, lines, 1, CV_PI/180, 80, 30, 10 );

pretty much matches the declaration:

void HoughLinesP(Mat& image, vector<Vec4i>& lines, double rho, double theta, int threshold, double minLineLength=0, double maxLineGap=0);

except that you are passing integers instead of doubles, so that should rather be

HoughLinesP( dst, lines, 1.0, CV_PI/180.0, 80.0, 30.0, 10.0 );
0
panJamesAuthor Commented:
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



0
Infinity08Commented:
>> first argument argc is integer, why don't I actually pass it?

The operating system takes care of that for you. All the parameters you pass on the command line will be placed in the argv array, and argc will contain the amount of items in that array.


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

I'll leave this one for someone who actually uses VC++. But there should be an option to set the command line arguments for debugging. jkr ?
0

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
jkrCommented:
You can enter your arguments in the Project Settings, category 'Debug'.
0
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today
C++

From novice to tech pro — start learning today.

Question has a verified solution.

Are you are experiencing a similar issue? Get a personalized answer when you ask a related question.

Have a better answer? Share it in a comment.