Can anyone help me?

[Edit: one link is enough dude..]

Thank u

It is really a very good idea this “shared buffer”.
I only saw that on your blog.

I am a composer and I am currently developing software to make music with a webcam: NoizeKam
You can find here: http://blog.oliviergest.net/noizekam/

I am using OpenCV and STK, but now I use only PortAudio and I started to integrate QT for the interface and OpenGL.
I had already tested QT, but it slows down the execution.
I will try your method of shared buffer because I think it should speed up my soft and eat less CPU cycles.

Again thank you for sharing your knowledge (everyone does not, that’s a shame) and your help is so valuable in this area.

PS: translated from French into English by my friend Google

My method, I believe, is better since I’m not shuffling bits around. The memory buffer is shared between OpenCV IplImage and Qt’s QImage.
When the byte-order (888 RGB interleave) is the same, there’s no problem in sharing buffers.

My method doesn’t require copying the IplImage->imageData, as that guy does in “void QOpenCVWidget::putImage(IplImage *cvimage)”. He also uses a less optimized way of using QImage.setPixel for each pixel, this can be done faster (memcpy for each row?).

Roy.

Is this method (create only the header, as the data buffer is shared, and was allocated by QImage) faster than the method on qt-apps : http://www.qt-apps.org/content/show.php/Qt+Opencv+webcam+viewer?content=89995 ??

(sorry for my poor english )

thx in advance

This is brilliant. I agree with Dat Chu that you should consider to share the application on gt-apps.org because I found it will be easier for a beginner like me to start from it.

Here at the Additional Dependencies you should have the following : qtmaind.lib QtCored4.lib QtGuid4.lib (!!SUPPOSING you have correctly installed QT and qt plugin for visual studio). Next: add 3 more libraries: cv.lib cxcore.lib highgui.lib -> these are from OpenCV.

This will only work if you previously defined the path to OpenCV’s include, source directories in Visual Studio tool bar -> Tools -> Options -> Projects and Solutions -> VC++ Directories. In this place you define the path to QT’s directories too.

Search Google for “installing OpenCV/ QT with Visual Studio”.

Good luck!

I am having problem to build the above code in Qt 4.5.1 editor.

undefined reference to `cvCreateImage’

The above message is mentioned in the editor. The opencv and Qt variables have been detected but the funcitons couldn’t be detected because somehow the libraries should be linked.

If anyone could help in this regard.

Moreover what editor and libraries had been used in the above code.

With Best Regards,
Asif Sardar.

I sorted out the above error, don’t use ui.frame->setminimumsize etc. Just use it like

setminimumsize() …

Then the compiler does not create problem. We don’t need to reference the frame when we setupUi for the widget.

With Best Regards,
Asif Sardar.