problem opencv, qt, c++, win10

jsulm

@CHRISTIANo. You should first make sure you could open the image successfully as shown here: http://docs.opencv.org/2.4/doc/tutorials/introduction/display_image/display_image.html

There is even a whole example without Qt:

#include <opencv2/core/core.hpp>
#include <opencv2/highgui/highgui.hpp>
#include <iostream>

using namespace cv;
using namespace std;

int main( int argc, char** argv )
{
    if( argc != 2)
    {
     cout <<" Usage: display_image ImageToLoadAndDisplay" << endl;
     return -1;
    }

    Mat image;
    image = imread(argv[1], CV_LOAD_IMAGE_COLOR);   // Read the file

    if(! image.data )                              // Check for invalid input
    {
        cout <<  "Could not open or find the image" << std::endl ;
        return -1;
    }

    namedWindow( "Display window", WINDOW_AUTOSIZE );// Create a window for display.
    imshow( "Display window", image );                   // Show our image inside it.

    waitKey(0);                                          // Wait for a keystroke in the window
    return 0;
}

CHRISTIANo.

I DON'T HAVE ERROR....

compiled sucessfull.... and i have the same result.... no upload the image :(

mrjj

@CHRISTIANo.

Did you try the code @jsulm showed ?
it contains check if image can load which your code did not have.

 if(! image.data )                              // Check for invalid input
    {
        cout <<  "Could not open or find the image" << std::endl ;
        return -1;
    }

jsulm

@CHRISTIANo. I'm not talking about compiler errors. I'm talking about this:

if(! image.data )                              // Check for invalid input
    {
        cout <<  "Could not open or find the image" << std::endl ;
        return -1;
    }

to make sure the image was loaded.
And you should start with the example I provided without Qt. If it is working then add it to your Qt app.

CHRISTIANo.

This is my code, i don´t find the solution..?

#include <opencv2/core/core.hpp>
#include <opencv2/highgui/highgui.hpp>
#include <iostream>

using namespace cv;
using namespace std;

int main( int argc, char** argv )
{
    if( argc != 2)
    {
     cout <<" Usage: display_image ImageToLoadAndDisplay" << endl;
     return -1;
    }

    Mat image;
    image = imread("C:\\opencv\\programas\\2\\cris.png");   // Read the file

    if(! image.data )                              // Check for invalid input
    {
        cout <<  "Could not open or find the image" << std::endl ;
        return -1;
    }

    namedWindow( "Display window", WINDOW_AUTOSIZE );// Create a window for display.
    imshow( "Display window", image );                   // Show our image inside it.

    waitKey(0);                                          // Wait for a keystroke in the window
    return 0;
}

her the .PRO

TEMPLATE = app
CONFIG += console c++11
CONFIG -= app_bundle
CONFIG -= qt

SOURCES += main.cpp

win32:CONFIG(release, debug|release): LIBS += -L$$PWD/../../build/x64/vc11/lib/ -lopencv_calib3d249 -lopencv_contrib249 -lopencv_core249 -lopencv_features2d249 -lopencv_flann249 -lopencv_gpu249 -lopencv_highgui249 -lopencv_imgproc249 -lopencv_legacy249 -lopencv_ml249 -lopencv_nonfree249 -lopencv_objdetect249 -lopencv_ocl249 -lopencv_photo249 -lopencv_stitching249 -lopencv_superres249 -lopencv_ts249 -lopencv_video249 -lopencv_videostab249
else:win32:CONFIG(debug, debug|release): LIBS += -L$$PWD/../../build/x64/vc11/lib/ -lopencv_calib3d249d -lopencv_contrib249d -lopencv_core249d -lopencv_features2d249d -lopencv_flann249d -lopencv_gpu249d -lopencv_highgui249d -lopencv_imgproc249d -lopencv_legacy249d -lopencv_ml249d -lopencv_nonfree249d -lopencv_objdetect249d -lopencv_ocl249d -lopencv_photo249d -lopencv_stitching249d -lopencv_superres249d -lopencv_ts249d -lopencv_video249d -lopencv_videostab249d lopencv_highgui249d

INCLUDEPATH += $$PWD/../../build/include
DEPENDPATH += $$PWD/../../build/include/opencv2

win32:CONFIG(release, debug|release): LIBS += -L$$PWD/../../build/x86/vc11/lib/ -lopencv_calib3d249 -lopencv_contrib249 -lopencv_core249 -lopencv_features2d249 -lopencv_flann249 -lopencv_gpu249 -lopencv_highgui249 -lopencv_imgproc249 -lopencv_legacy249 -lopencv_ml249 -lopencv_nonfree249 -lopencv_objdetect249 -lopencv_ocl249 -lopencv_photo249 -lopencv_stitching249 -lopencv_superres249 -lopencv_ts249 -lopencv_video249 -lopencv_videostab249
else:win32:CONFIG(debug, debug|release): LIBS += -L$$PWD/../../build/x86/vc11/lib/ -lopencv_calib3d249d -lopencv_contrib249d -lopencv_core249d -lopencv_features2d249d -lopencv_flann249d -lopencv_gpu249d -lopencv_highgui249d -lopencv_imgproc249d -lopencv_legacy249d -lopencv_ml249d -lopencv_nonfree249d -lopencv_objdetect249d -lopencv_ocl249d -lopencv_photo249d -lopencv_stitching249d -lopencv_superres249d -lopencv_ts249d -lopencv_video249d -lopencv_videostab249d lopencv_highgui249d

INCLUDEPATH += $$PWD/../../build/include
DEPENDPATH += $$PWD/../../build/include/opencv2

WIN10
64BITS
OPENCV 2.4.9
CMAKE 3.1.0
VSIUAL STUDIO 2012

joeQ

@CHRISTIANo. hi,

can you show me your example png file ? is it transparent ?

did you test another image file, like jpeg.

or modify the \\ to / try it.

imread("C:/opencv/programas/2/cris.png");

jsulm

@CHRISTIANo. What exactly happens with this code? Is the image not shown? Is "Could not open or find the image" printed?
Can you open this PNG file in an image viewer?

mrdebug

Please use this standard approach

imagen = imread("C:/opencv/programas/2/cris.png");

Try

while (1) {
    Mat imagen = imagen = imread("C:/opencv/programas/2/cris.png");
    imshow("imagen",imagen);
    if (waitKey(30) == 27); //wait for 'esc' key press for 30ms. If 'esc' key is pressed, break loop
}

CHRISTIANo.

well...
the specific problem is that my code compiled sucessfull, but when run this program, not appear nothig , only "Press <RETURN> to close this window...", as that has been finally
I BELIEVE that is my QT 4.4.0 that not function with my VISUAL STUDIO 2012

in disk C.... "C:\Qt\5.2.1\msvc2012_64 " can you help..!!

here can provide this imag
i test with a camera and nothing....
i test with "/" and nothing

mrdebug

Have you build opencv yourself? If I remember correctly opencv is built with msvc 2015 and your Qt package is so outdated...

mrdebug

I suggest you to upgrade yout visual studio installation, to check to have msvc 2015, the already built opencv package and Qt 5.9.1 built with msvc 2015.

jsulm

@CHRISTIANo. You should check which compiler was used to build OpenCV. You need a build done with same compiler.