Qt5 and Tesseract 3.04.01in Ubuntu

bhavin03

Hallo, I am integrating Tesseract OCR in Qt. While in the Debug mode (no optimization used ..!), everything works perfect. The OCR result ist quite good in debug mode. But when I just run without debugging, it just outputs totally wrong ( but everytime same result ) result. I dont know where to start. Because when I compile the same code (without Qt Framework code ) in linux GCC, it works great. Please give me any hint, where to start digging..

Will be very thankful for any hint.. !!

SGaist

Hi and welcome to devnet,

That's pretty strange. Are you sure you are linking against the correct libraries ? i.e. release version of Tesseract when build against release version of your application ?

bhavin03

Actually I compiled tesseract myself from source. I have also tried to link against library downloaded via "apt-get install tesseract-ocr". But same result.. I am really stuck now.. Thinking of IPC between two binaries (Qt for frontend and Mingw compiled binary for backend...!), but it's not effective way though..!

Regards...!!

SGaist

Can you provide a minimal sample that shows that strange behavior ?

bhavin03

Hallo,
Here the result in Debug version : Link
And here the result in Run Version : Link

With Regards

SGaist

Silly question, is it only the visualization that's messed or is it the result returned by tesseract that is different ? e.g. does printing the string on the console show the same difference ?

bhavin03

Hi,
It has nothing to do with output.. I met some interesting scenario. When I create the Qt project in commandline without QAppliction framework

int main(int argc, char *argv[])
{
//QApplication a(argc, argv);
 CODE
//return a.exec();.
}

it just works fine. As soon as I uncomment QApplication a(argc, argv); and return a.exec(); it just gives wrong result.. I dont know now, what effect has QApplication Framework on Tesseract Code..??

SGaist

How are you initializing the tesseract API ?

bhavin03

#include <QApplication>
#include <tesseract/baseapi.h>
#include <leptonica/allheaders.h>

int main()
{
    //QApplication a(argc, argv);
    char *outText;

    tesseract::TessBaseAPI *api = new tesseract::TessBaseAPI();
   
    if (api->Init(NULL, "eng")) {
        fprintf(stderr, "Could not initialize tesseract.\n");
        exit(1);
    }

   
    Pix *image = pixRead("/home/ubuntu/Desktop/image.png");
	
	api->SetPageSegMode(tesseract::PSM_AUTO_OSD);
    api->SetImage(image);
   
    // OCR result
    outText = api->GetUTF8Text();
    printf("OCR output:\n%s", outText);

    // Destroy used object and release memory
    api->End();
    delete [] outText;
    pixDestroy(&image);

    return 0;
   //return a.exec();
}