Snapshot problem

[PAP]

Hi,

at first sorry for my english. I have USB camera DFx 21BUC03 and I would like to make simple program, which will sample scene every ~34 ms. I need to work with OpenCV. I have program, which sample only first image. Where is mistake?



int main(void)
{
LONG imSize;
BOOL result;
Grabber *pGrabber;
/* MemBufferCollection::tBmInfHPtr pInf;*/
tFrameHandlerSinkPtr pSink;
MemBufferCollection::tMemBufferPtr pBuffer;
IplImage *img;

pGrabber = new DShowLib::Grabber();
assert(pGrabber);

if( !DShowLib::InitLibrary( "...." ) )
{
printf("The library could not be initialized ");
printf("(invalid license key?).\n");
exit( 1 );
}

pGrabber->showDevicePage();
pSink = FrameHandlerSink::create(1);
pGrabber->setSinkType(pSink);
pGrabber->startLive(false);
cvNamedWindow("img",CV_WINDOW_AUTOSIZE);
imSize = IM_WIDTH * IM_HEIGHT * 32 / 8;
img = cvCreateImage( cvSize(744,480),IPL_DEPTH_8U , 4);

for(INT16 i = 0; i < 1000; i++)
{

pSink->snapImages(1);
pBuffer = pSink->getLastAcqMemBuffer();

/*pInf = pBuffer->getBitmapInfoHeader();*/
/*imSize = pInf->biWidth * pInf->biHeight * pInf->biBitCount / 8;*/

memcpy((unsigned char *)img->imageData, pBuffer->getPtr(), imSize);

cvShowImage("img",img);

Sleep(30);
}

pGrabber->stopLive();
pGrabber->closeDev();


pSink = NULL;
pBuffer = NULL;

cvDestroyWindow("img");
cvReleaseImage(&img);

return 0;
}


I thank for response ...

[Michael Kirmse]

Hello PAP

I compiled your code on my computer and it works as expected.

[PAP]

Hello PAP

I compiled your code on my computer and it works as expected.

Thanks Michael,
but did you get two differen image in two different steps "i"?

[Michael Kirmse]

Yes, I did.

[PAP]

Yes, I did.

You have right! Thanks!

I tested save images in loop and images were different. Problem will be in cvShowImage, because window "img" doesn't redraw. When I minimized and maximized "img" window, images was different.

The window freeze over and the image is overturned, I don't know why ...

[PAP]

I solved problem with redraw window: With using Win API GetAcitveWindow and UpdateWindow.

[Michael Kirmse]

I am very glad to hear this, thank you for the feedback.