New in opencv2.3.1 and Qt

**danilodsp** · 28th October 2011, 00:29

Hello friends,

I decided to work with Qt more opencv,
I using the book "OpenCV 2 Computer Vision Application Programming Cookbook", and followed this tutorial:
http://knowtheabc.wordpress.com/2011...nd-qt-creator/

My code is:
(.pro)

Qt Code:

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INCLUDEPATH += C:/opencv/build/include/
 
 LIBS += "C:/opencv/build/lib/libopencv_core231.dll.a" \
 "C:/opencv/build/lib/libopencv_highgui231.dll.a" \
 "C:/opencv/build/lib/libopencv_imgproc231.dll.a" \
 "C:/opencv/build/lib/libopencv_features2d231.dll.a" \
 "C:/opencv/build/lib/libopencv_calib3d231.dll.a"

INCLUDEPATH += C:/opencv/build/include/

 LIBS += "C:/opencv/build/lib/libopencv_core231.dll.a" \
 "C:/opencv/build/lib/libopencv_highgui231.dll.a" \
 "C:/opencv/build/lib/libopencv_imgproc231.dll.a" \
 "C:/opencv/build/lib/libopencv_features2d231.dll.a" \
 "C:/opencv/build/lib/libopencv_calib3d231.dll.a"

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(.cpp)

Qt Code:

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#include <opencv2/core/core.hpp>
 #include <opencv2/highgui/highgui.hpp>
 
 int main()
 {
 cv::Mat imagem = cv::imread("C:/lena.jpg");
 cv::namedWindow("Teste");
 cv::imshow("Teste", imagem);
 cv::waitKey(5000);
 
 return 1;
 }

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

 int main()
 {
 cv::Mat imagem = cv::imread("C:/lena.jpg");
 cv::namedWindow("Teste");
 cv::imshow("Teste", imagem);
 cv::waitKey(5000);

 return 1;
 }

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the output is:
"Press <RETURN> to close this window..."
and nothing more.

Making test with stdio and printf I can only print on the screen before of the
my code (just the beginning of the main). If after the code, nothing appears.
(just "Press <RETURN> (...)").

I had enough sense to put the .dll along with the .exe, and also to put the
image in the correct directory.

I tried in my (.pro):

Qt Code:

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INCLUDEPATH += C:/opencv/build/include/
 
LIBS += C:/opencv/build/bin/*.dll

INCLUDEPATH += C:/opencv/build/include/

LIBS += C:/opencv/build/bin/*.dll

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but nothing.

In Qt GUI, the window does not open when I use any function opencv.

I hope some help.
Sorry my english.

.,

Added after 25 minutes:

I discovered the error.
I was making two errors.

I did not copy all the dlls required:
QtOpenGL4.dll, QtTest4.dll, ...

And I was copying the dll of the opencv the wrong path. Path correct is (<buld path>/bin/*.dll).

**abhigarg** · 12th November 2012, 16:14

try this path for the image:
"C://lena.jpg"

if this doesnt help then try using some image on the desktop because sometimes the OS (mostly windows) does not allow permissions to access data in c drive.