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未显示Sobel产出的开放录像带
原标题:Opencv video frame not showing Sobel output

This is a continuation question from Opencv video frame giving me an error I think I closed it off, Im new to Stackoverflow.

I have code below that Im trying to see its Sobel edge image. However the program runs but the output is just a grey screen where if I mouseover the cursor disappears. Does anyone see the error? or is it a misunderstanding about the data structures Im using

IplImage *frame, *frame_copy = 0;

// capture frames from video
CvCapture *capture = cvCaptureFromFile( "lightinbox1.avi");
//Allows Access to video propertys
cvQueryFrame(capture);

//Get the number of frames
int nframe=(int) cvGetCaptureProperty(capture,CV_CAP_PROP_FRAME_COUNT);

//Name window
cvNamedWindow( "video:", 1 );

//start loop
for(int i=0;i<nframe;i++){
//prepare capture frame extraction
cvGrabFrame(capture);
cout<<"We are on frame "<<i<<"
";
//Get this frame
frame = cvRetrieveFrame( capture );
con2txt(frame);
frame_copy = cvCreateImage(cvSize(frame->width,frame->height),IPL_DEPTH_8U,frame->nChannels );
//show and destroy frame
cvCvtColor( frame,frame,CV_RGB2GRAY);

 //Create Sobel output
 frame_copy1 = cvCreateImage(cvSize(frame->width,frame->height),IPL_DEPTH_16S,1 );
cvSobel(frame_copy,frame_copy1,2,2,3);

cvShowImage("video:",frame_copy1);
cvWaitKey(33);}
cvReleaseCapture(&capture);
最佳回答

在本案中,我认为,这是因为你制造的目的地形象不同于原来的 深度:

frame_copy1 = cvCreateImage(cvSize(frame->width,frame->height),IPL_DEPTH_16S,1 );

并且应该:

frame_copy1 = cvCreateImage(cvSize(frame->width,frame->height),IPL_DEPTH_8U,1 );

无论如何,ts post显示了使用cvSobel的例子。

问题回答

我认为,开放世界论坛正在明智地展示你的16个轨道形象。 您可以采取以下步骤,核实情况是否如此:

  1. Create an 8 bit image (call it result8bit). OpenCV is good at displaying these.
  2. Calculate the minimum and maximum of frame_copy1 (see cvMinMaxLoc)
  3. Use cvScale to convert frame_copy1 to result8bit using the minimum and maximum to scale the image
  4. Show result8bit.

Good luck.





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