andrea.delbravo's profile - activity

Hello, I' using the 2.4.3. version (OpenCV) and I'm trying to use the Qt extension. my questions are: 1) how to manage the menu entries of the window made by cvNamedWindow. I mean....by default there is a standard menu configuration with some icons for panning, zooming etc...and one entry ti save the file....but if you choose to save the file nothing happens...I suppose that some code shall be added...I suppose there is some possibility to derive a class from the base class to overload some functions in order to customize the window menu behaviour.. any ideas? 2) Y tried to compile the samples under the samples/cpp/Qt_sample directory but the compiler failed on the cvCreateOpenGLCallback.....I tried to understand just to be sure that some include files were not missing but.....I didn't find any definition of the function cvCreateOpenGLCallback in any of the include files of openCV....

Thanks a lot

Operating System Fedora Core 17 gcc version 4.7.2 20120921 (Red Hat 4.7.2-2) (GCC)

I've loaded almost all the dependencies on order to have most of the functionalities in OpenCV. The CMake process finished without problem, after adjusting properly all the flags, but when compiling the following error is issued:

/media/DATA/Unix/SG_SIM_ENV/OpenCV/OpenCV-2.4.3/OpenCV2.4.3/modules/objdetect/src/cascadedetect.cpp: In member function ‘void Logger::write()’:
/media/DATA/Unix/SG_SIM_ENV/OpenCV/OpenCV-2.4.3/OpenCV-2.4.3/modules/objdetect/src/cascadedetect.cpp:108:9: error: ‘imwrite’ is not a member of ‘cv’
make[2]: *** [modules/objdetect/CMakeFiles/opencv_objdetect.dir/src/cascadedetect.cpp.o] Errore 1
make[1]: *** [modules/objdetect/CMakeFiles/opencv_objdetect.dir/all] Errore 2
make: *** [all] Errore 2

It seems that the compiler doesn't recognize imwrite as a memder function of namespace cv: I've checked that in highgui.hpp, imwrite is in the cv namespace. Before trying to find a solution by myself, I'd like to know if somebpdy else had the same problem. Thanks alot

Hello, I experimented the new GUI: it is really nice...I'm wondering if there is some way to customize the interface, for instance, select a file to load, and not only a file where to save the current image....any suggestion on where to start?

Found the solution.... If you install the framework from rpm using for example yum in Fedora 17, you will not get Qt functionalities and your libraries do not contain the related functions. In order to get full functionalities (qt and others third parties) you havi to to download the source, set up the CMakeFile, install the appropriate third party libraries, compile and install. In thi way you will get the qt functionalities

I'm trying to use the new qt functionalities but i have problem in the link phase...I don't know what libs to link to have cvCreateButton available. Any suggestion? Thanks a lot

PS the example I'm trying to compile is in the user guide for OpenCV 2.3.1

I try to use the new Qt funtions but I don't which libraries to link, for example, to fine the function cvCreateButton

Hello to everybody, openCV is a wonderful framework, but I was wondering if there is the possibility to insert on top of the windows the standard menu as in many windows application, like for example, file management (load, save, save as etc) or menu like "modify" with undo functionality and so on. It is possible to attach the openCV windows to the standard window manager of the operating system? (like Linux). I'm running openCV on a work-station with Fedora. Thanks a lot

I solved the problem providing a simple algorithm: most of the data where in a very narrow interval but very few pixels outside the interval, as you correctly supposed. I set two threshold, min and max, and for every pixel below min I set the value to zero, and for every pixel upper than max I set the value to max (just to increase the dynamic of image). After this process only pixel between min and max are present. After that, I scaled their values between 0 and 65535. I put also two sliders to set up min and max, and the results was really fantastic....For sure there is some automatic functio in openCv to do that....I wiil learn it in the future, but openCV is really superb. It allowed me with a minimum trainig to achieve a real valuable results

Thanks a lot, I followed the suggestion but still I've some problems. The source matrix had all values in a very small interval (so the results was an almost gray image). I expected that after applying the normalize function, the values were scaled between the min and max, but the result was similar to the source matrix: the values are still in a very small interval (shifted at a higher value respect the original matrix); the result is a similar image but a little bit brighter.
Where am I wrong?

Hello, I managed to load an IR image captured by an IR camera with a legacy format. I manage to see the image which are with a very poor contrast (almost grey, but something can be seen). I tried to save the image in a bmp format (imwrite("filename.bmp", image_IR)) but the resulting image is completely white.

Does anybody have any suggestion?

Hello, I'm very new to OpenCV. My question is: I need to enhance contrast of an IR image. I tried to use the cvEqualizeHist C function and the equalizeHist C++ function, but I understood they both work on 8 bit data, whilst my pixel data (one channel) are 16 bit (CV_16UC1). Is it possible to improve contrast in my image in some other way? Thanks a lot Andrea

Update: Thanks a lot, I followed the suggestion but still I've some problems. The source matrix had all values in a very small interval (so the results was an almost gray image). I expected that after applying the normalize function, the values were scaled between the min and max, but the result was similar to the source matrix: the values are still in a very small interval (shifted at a higher value respect the original matrix); the result is a similar image but a little bit brighter. Where am I wrong?