opencv 如何显示多幅图像

       主函数是用于读取摄像头，并在视频上写时间字幕：

     

   CvCapture* capture;   

  
      capture = cvCaptureFromCAM(0);
 

   IplImage* frame;

   cvNamedWindow("video",1);
   cvResizeWindow("video",750,750);

   CvFont timeFont,timeFont1;
   cvInitFont(&timeFont,  CV_FONT_HERSHEY_COMPLEX, 1.0f,1.0f,0,1,8);
   cvInitFont(&timeFont1, CV_FONT_HERSHEY_COMPLEX, 1.0f,1.0f,0,1,8);

   // Initialize new applied memory of 'time1'
 char timestr[25];
   memset(timestr, 0, 25 * sizeof(char));

   while (1)
   {
      frame = cvQueryFrame( capture );
      if (!frame) break;

      // Get the systme local time info
      time_t rawtime;
      struct tm* timeinfo;
      //time( &rawtime ); 

      rawtime = time( NULL );
      timeinfo = localtime( &rawtime );
      char* p = asctime( timeinfo );

      // the 25th character of array 'p' is '/n'
      // but it can not be display correctly in the image
      // so we just read out the first 24 character of 'p'
 for (int i = 0; i < 24; i++)
      {
         timestr[i] = *p;
         p++;
      }
      p = NULL;

      // Bitwise inversion of every element of the current frame
      IplImage* frame_not = cvCreateImage(cvGetSize(frame),frame->depth,frame->nChannels);
      cvNot(frame,frame_not);

      // Get the gray scale image of the current frmae
      // and transform the gray image from single channel to three channels
      IplImage* frame_gray=cvCreateImage(cvGetSize(frame),frame->depth,1);
      IplImage* frame1=cvCreateImage(cvGetSize(frame),frame->depth,frame->nChannels);
      cvCvtColor(frame,frame_gray,CV_RGB2GRAY);
      cvCvtColor(frame_gray,frame1,CV_GRAY2BGR);

      // Do Canny edge detection
      // and transform the result image from single channel to three channels
      IplImage* frame_canny=cvCreateImage(cvGetSize(frame),frame->depth,1);
      IplImage* frame2=cvCreateImage(cvGetSize(frame),frame->depth,frame->nChannels);
      cvCanny(frame_gray,frame_canny,20,75,3);
      cvCvtColor(frame_canny,frame2,CV_GRAY2BGR);

      // Display the local time information in each image
      cvPutText( frame,        timestr, cvPoint(5,25), &timeFont,  CV_RGB(255,0,0) );
      cvPutText( frame1,    timestr, cvPoint(5,25), &timeFont,  CV_RGB(255,0,0) );
      cvPutText( frame2,    timestr, cvPoint(5,25), &timeFont1, CV_RGB(255,0,0) );
      cvPutText( frame_not, timestr, cvPoint(5,25), &timeFont1, CV_RGB(255,0,0) );

下面的是如何在一幅图像上显示多幅图像：

   // img - Used for getting the arguments 
   IplImage* img;

   // DispImage - the image in which all the input images are to be copied
   IplImage* DispImage;

   int size;    // size - the size of the images in the window
 int ind;        // ind - the index of the image shown in the window
 int x, y;    // x,y - the coordinate of top left coner of input images
 int w, h;    // w,h - the width and height of the image

   // r - Maximum number of images in a column
   // c - Maximum number of images in a row 
 int r, c;

   // scale - How much we have to resize the image
 float scale;
   // max - Max value of the width and height of the image
 int max;
   // space - the spacing between images
 int space;

   // If the number of arguments is lesser than 0 or greater than 12
   // return without displaying 
 if(nArgs <= 0) {
      printf("Number of arguments too small..../n");
      return;
   }
   else if(nArgs > 12) {
      printf("Number of arguments too large..../n");
      return;
   }
   // Determine the size of the image,
   // and the number of rows/cols
   // from number of arguments 
 else if (nArgs == 1) {
      r = c = 1;
      size = 300;
   }
   else if (nArgs == 2) {
      r = 2; c = 1;
      size = 300;
   }
   else if (nArgs == 3 || nArgs == 4) {
      r = 2; c = 2;
      size = 300;
   }
   else if (nArgs == 5 || nArgs == 6) {
      r = 3; c = 2;
      size = 200;
   }
   else if (nArgs == 7 || nArgs == 8) {
      r = 4; c = 2;
      size = 200;
   }
   else {
      r = 4; c = 3;
      size = 150;
   }

   // Create a new 3 channel image to show all the input images
   DispImage = cvCreateImage( cvSize(60 + size*r, 20 + size*c), IPL_DEPTH_8U, 3 );

   // Used to get the arguments passed
   va_list args;
   va_start(args, nArgs);

   // Loop for nArgs number of arguments
   space = 20;
   for (ind = 0, x = space, y = space; ind < nArgs; ind++, x += (space + size)) {

      // Get the Pointer to the IplImage
      img = va_arg(args, IplImage*);

      // Check whether it is NULL or not
      // If it is NULL, release the image, and return
 if(img == 0) {
         printf("Invalid arguments");
         cvReleaseImage(&DispImage);
         return;
      }

      // Find the width and height of the image
      w = img->width;
      h = img->height;

      // Find whether height or width is greater in order to resize the image
      max = (w > h)? w: h;

      // Find the scaling factor to resize the image
      scale = (float) ( (float) max / size );

      // Used to Align the images
      // i.e. Align the image to next row
 if( ind % r == 0 && x!= space) {
         x  = space;
         y += space + size;
      }

      // Set the image ROI to display the current image
      cvSetImageROI(DispImage, cvRect(x, y, (int)( w/scale ), (int)( h/scale )));

      // Resize the input image and copy the it to the Single Big Image
      cvResize(img, DispImage);

      // Reset the ROI in order to display the next image
      cvResetImageROI(DispImage);
   }

   // Create a new window, and show the Single Big Image
   //cvNamedWindow( title, 1 );
   cvShowImage( title, DispImage);

效果图：

 

 

上面的程序都来自网上的。大家见谅啦~~~

from:http://www.opencv.org.cn/forum/viewtopic.php?f=1&t=7996&start=0

from:http://www.cppblog.com/qiujian5628/archive/2008/01/21/41562.html