Thread: how to display pixel data

Hi,

I have an array of pixel data which i want to display. How should I go by doing this? The pixel data (an image frame...about 262144 bytes) has a resolution of 512 by 512 displaying at 255 colours.

Do I have to convert it into a bitmap? I've searched around and people are using opencv. So i gave it a try but with no luck.

Any help would be really appreciated

thanks!

^^ thanks for your advice..i'll look into it

anyone else? does anyone have experience with openCV?

right now i have this in openCV:

Code:

IplImage* myimage = cvCreateImage(cvSize(width,width), IPL_DEPTH_8S, 1);

			char *data;
			data = (char*)myimage->imageData;


			for(int i = 0; i < width; i++){
				for(int j = 1; j <= width; j++){
						data[i*(myimage->widthStep)+j*(myimage->nChannels)] = result_data[counter];
						counter++;
				}
			}
		
			counter = 0;
			cvNamedWindow ("image", CV_WINDOW_AUTOSIZE); 
			cvShowImage ("image", myimage);
			cvWaitKey (0);
			cvReleaseImage (&myimage);
			cvDestroyWindow("image");

my result_data contains pixel data of type 8bit signed int (int8_t)

thanks in advance!

Originally Posted by vkoo

anybody?

Let me google "openvc bmp" for you
Let me google "IplImage" for you

Code:

IplImage* img=cvCreateImage(cvSize(640,480),IPL_DEPTH_8U,1);
CvScalar s;
s=cvGet2D(img,i,j); // get the (i,j) pixel value
printf("intensity=%f\n",s.val[0]);
s.val[0]=111;
cvSet2D(img,i,j,s); // set the (i,j) pixel value

Code:

      int nl= image->height; // number of lines

      int nc= image->width * image->nChannels; // total number of element per line

      int step= image->widthStep; // effective width

             

      // get the pointer to the image buffer

      unsigned char *data= reinterpret_cast<unsigned char *>(image->imageData);

 

      for (int i=1; i<nl; i++) {

            for (int j=0; j<nc; j+= image->nChannels) {

 

            // process each pixel ---------------------

                 

                  data[j]= data[j]/div * div + div/2;

                  data[j+1]= data[j+1]/div * div + div/2;

                  data[j+2]= data[j+2]/div * div + div/2;

 

            // end of pixel processing ----------------

 

            } // end of line

                   

            data+= step;  // next line

      }

Code:

  // load an image  
  img=cvLoadImage(argv[1]);
  if(!img){
    printf("Could not load image file: %s\n",argv[1]);
    exit(0);
  }

  // get the image data
  height    = img->height;
  width     = img->width;
  step      = img->widthStep;
  channels  = img->nChannels;
  data      = (uchar *)img->imageData;
  printf("Processing a %dx%d image with %d channels\n",height,width,channels); 

  // create a window
  cvNamedWindow("mainWin", CV_WINDOW_AUTOSIZE); 
  cvMoveWindow("mainWin", 100, 100);

  // invert the image
  for(i=0;i<height;i++) for(j=0;j<width;j++) for(k=0;k<channels;k++)
    data[i*step+j*channels+k]=255-data[i*step+j*channels+k];

  // show the image
  cvShowImage("mainWin", img );