How can I convert OPENGL canvas graphics into bitmap image format.

Question

I used the following code... but no conversion made... plz tell the write way..
public static void savePaintingJPG(GLCanvas canvas, String fileName) {
        // saves the content of the 'panel' in a file 'file'.jpg
        String name = "";
int framewidth = canvas.getSize().width; // get the canvas' dimensions
int frameheight = canvas.getSize().height;
System.out.println(framewidth);
System.out.println(frameheight);
  java.nio.ByteBuffer pixelsRGB = BufferUtils.newByteBuffer(framewidth * frameheight * 3); // create a ByteBuffer to hold the image data
GL gl = canvas.getGL(); // acquire our GL Object
      // read the Frame back into our ByteBuffer
gl.glReadBuffer(GL.GL_BACK);
gl.glPixelStorei(GL.GL_PACK_ALIGNMENT, 1);
gl.glReadPixels(0, 0, framewidth, frameheight, GL.GL_RGB, GL.GL_UNSIGNED_BYTE, pixelsRGB);
int[] pixelInts = new int[framewidth * frameheight*3];       // Convert RGB bytes to ARGB ints with no transparency. Flip image vertically by reading the
     // rows of pixels in the byte buffer in reverse - (0,0) is at bottom left in OpenGL.
int p = framewidth * frameheight * 3; // Points to first byte (red) in each row.
     int q;   // Index into ByteBuffer
  int i = 0;   // Index into target int[]
  int w3 = framewidth*3;    // Number of bytes in each row
  for (int row = 0; row < frameheight; row++) {
    p -= w3;
    q = p;
    for (int col = 0; col < framewidth; col++) {
      int iR = pixelsRGB.get(q++);
      int iG = pixelsRGB.get(q++);
      int iB = pixelsRGB.get(q++);
      pixelInts[i++] = 0xFF000000 | ((iR & 0x000000FF) << 16) | ((iG & 0x000000FF) << 8) | (iB & 0x000000FF);
        BufferedImage bimg = new BufferedImage(framewidth,frameheight,BufferedImage.TYPE_INT_ARGB);
          bimg.setRGB(0,0,framewidth, frameheight, pixelInts, 0, framewidth);
        try
            File imageFile = new File("final.jpg");
            File imagf = new File("final.png");
            File image = new File("final.bmp");
            ImageIO.write(bimg, "jpg", imageFile); // saves files
            ImageIO.write(bimg, "png", imagf);
            ImageIO.write(bimg, "bmp", image);
               System.out.println("Success");
        catch (IOException e) {
            e.printStackTrace();
    }

Answer 1

You want to convert it to an array of what? Of numbers? Of LabVIEW colors?
The "Read BMP File.vi" VI outputs a 1-D array of the pixels, but I suspect it is not exactly in the format that you need. I am NOT sure, but I think that each group of 3 elements of that 1-D array (which is inside the cluster "image data" that the VI outputs) represents the red, green and blue levels of a single pixel (but it may be hue, saturation and lum.). Also, since it is a 1-D array, you would have to divide it by the width (which is also included in the "image data" cluster) to get some sort of 2-D array of data.
You can find the "Read BMP File.vi" VI in the functions palete> "Graphics & sound">"Graphics Formats".