argv[1] loadImage problem xcode 3.2 and snow leopard

Question

Hi Im on mac snow leopard and test these code on xcode3.2 of the Learning OpenCV everything works fine but the image doesnt appear and in the windows. I had try to understand searching for two days what does argv[1] means, but Im still no clear. Im a newbie en C++. I had the image in the same directory where the main.cpp is

#include <OpenCV/cv.h>
#include <OpenCV/highgui.h>



int main(int argc, char** argv)
{
IplImage* interest_img;
CvRect interest_rect;
if( argc == 7 && ((interest_img= cvLoadImage( argv[1],1) ) != 0 ))
{

A more easy example is here:

http://books.google.cl/books?id=seAgiOfu2EIC&pg=PA17&lpg=PA17&dq=cvLoadImage%28argv[1]&source=bl&ots=hRJ5bhkAOf&sig=gyYAqZBnS6lCCXJz9Fz7vzOsF-U&hl=es&ei=dvdvS-fWG8eWtgePy_WCBg&sa=X&oi=book_result&ct=result&resnum=6&ved=0CBwQ6AEwBTgK#v=onepage&q=cvLoadImage%28argv[1]&f=false

both I have test it but they dont work. Please help me

Answer 1

argv[1] is the first command line argument.

It looks like the program is expcing you to supply 6 command line arguments, the first of which is the file name.

You can specify command line arguments in Xcode by doing a "Get Info" on your executable, setting the working directory (set it to Project or Custom, depending on your needs), and then click on the Arguments tab.

Answer 2

Dear Paul

Thanks a lt I dont put all the code of the program but Im trying to load an image using

#include "OpenCV/cv.h"
#include "OpenCV/highgui.h"

// ch3_ex3_13 image_name x y width height add# 

int main(int argc, char** argv)
{
    IplImage* interest_img=0;
    CvRect interest_rect;
    if( argc == 7 && ((interest_img=cvLoadImage(argv[1],1)) != 0 ))
    {


  interest_rect.x = atoi(argv[2]);
        interest_rect.y = atoi(argv[3]);
        interest_rect.width = atoi(argv[4]);
        interest_rect.height = atoi(argv[5]);
        int add = atoi(argv[6]);

        // Assuming IplImage *interest_img; and 
        //  CvRect interest_rect;
        //  Use widthStep to get a region of interest
        //
        // (Alternate method)
        //
        IplImage *sub_img = cvCreateImageHeader(
            cvSize(
                interest_rect.width, 
                interest_rect.height
                ),
            interest_img->depth, 
            interest_img->nChannels
            );

        sub_img->origin = interest_img->origin;

        sub_img->widthStep = interest_img->widthStep;

        sub_img->imageData = interest_img->imageData + 
  interest_rect.y * interest_img->widthStep  +
  interest_rect.x * interest_img->nChannels;

        cvAddS( sub_img, cvScalar(add), sub_img );

        cvReleaseImageHeader(&sub_img);

        cvNamedWindow( "Roi_Add", CV_WINDOW_AUTOSIZE );
        cvShowImage( "Roi_Add", interest_img );
        cvWaitKey();
    }
    return 0;
}

I put the image test.jpg inside the my_proyect folder and other one in the my_proyect/build/Debug directory but doesnt work

Is there something I made wrong? thanks