Substitute for get(); when using processing video.

elliot

I'm trying to figure out a way to get a section of pixels from a video and then be able to display that section of pixels how I chose. For example capturing video though built in camera loading in the pixels and then being able to draw a section of those pixels. So for instance you could split the video in to a 2x2 grid and then though getting the sections of pixels you could display the top right section in the bottom left section.

I have done this with images quite easily with the get(); function. This function is unavailable with video. I have also seen that Capture.crop no longer exists in the video library.

Any suggestions would be great!

GoToLoop

• Video inherits from PGraphics which inherits from PImage.
• Therefore, all of them got method get(): https://processing.org/reference/PImage_get_.html

elliot

Thanks for your reply! I now see how that relates. I found a useful post on stack overflow http://stackoverflow.com/questions/17705781/video-delay-buffer-in-processing-2-0

I ended up extending that by copying the previous frame by using createImage() and image.copy(). I then could use a for loop to iterate through the PImage array and get sections from that as they were delayed images not video. They are only delayed by 2 frames.

Here is my test:

    /*Substitute for get(); when using processing video.
    Elliot 25/03/15
    Reference: http://stackoverflow.com/questions/17705781/video-delay-buffer-in-processing-2-0
    */
    import processing.video.*;

        Capture cam;
        PImage image;
        PImage[][][] newImage = new PImage [3][3][3];
        int w = 1280;
        int h = 720;
        int numFrames = 3;
        int iWrite = 0, iRead = 1;


        void setup() {
          size(700, 700);
          cam = new Capture(this, w, h);
          cam.start();
          //newImage = new PImage[nFrames];
        }

        void draw() {
          if (cam.available()) {
            cam.read();
            PImage image = createImage(cam.width, cam.height, RGB);
            image.copy(cam, 0, 0, cam.width, cam.height, 0, 0, cam.width, cam.height);
            image.resize(900, 600);
            for (int i = 0; i < 3; i++) {
              for (int j = 0; j < 3; j++) {
                newImage[iWrite][i][j] = image.get(i*300, j*200, 300, 200);
              }
            }

             for (int i = 0; i < 2; i++) {
                for (int j = 0; j < 2; j++) {
                  if (newImage[iRead][i][j] != null) {
                    //image(newImage[iRead][i][j], i*300/2, j*200/2);

                    image(newImage[iRead][i][j], 300, 200);
                    image(newImage[iRead][i][j], 150, 200);
                    image(newImage[iRead][i][j], 0, 200);
                    image(newImage[iRead][i][j], 0, 100);
                    image(newImage[iRead][i][j], 0, 60);
                    image(newImage[iRead][i][j], 100, 150);
                    image(newImage[iRead][i][j], 200, 300);

                    // image(buffer[iRead], 50, 50);
                  }
                  iWrite++;
                  iRead++;
                  if (iRead >= numFrames-1) {
                    iRead = 0;
                  }
                  if (iWrite >= numFrames-1) {
                    iWrite = 0;
                  }
                }
              }
            }
        }