Get pixeldata of capture image in P3D

Svensolovsky

Hey ho everybody!

i have trouble in getting colorinformations from an captured webcam image. its no problem to use the camera picture as an texture for some vertexes... but i want to analyse the dynamical colorchange of each pixel the camera tracks.

thats exatly what i want to do... just using P3D:

    import processing.video.*;
    final int VIDEO_WIDTH  = 320;
    final int VIDEO_HEIGHT = 240;
    // Anzahl der Quadranten in der Breite
    final int VIDEO_COLS   = 8;
    // Anzahl der Quadranten in der Höhe
    final int VIDEO_ROWS   = 6;
    float[] activity = new float[VIDEO_COLS * VIDEO_ROWS];
    float[] buffer1 = new float[VIDEO_WIDTH * VIDEO_HEIGHT];
    float[] buffer2 = new float[buffer1.length];
    float[] buffer3 = new float[buffer1.length];
    Capture cam = null;

    void setup () {
      size (VIDEO_WIDTH, VIDEO_HEIGHT);
      cam = new Capture (this, VIDEO_WIDTH, VIDEO_HEIGHT, 15);
      frameRate (15);
    }

    void draw () {

      if (cam.available ()) {

        cam.read ();

        int index;
        int pxPerCol = VIDEO_WIDTH / VIDEO_COLS;
        int pxPerRow = VIDEO_HEIGHT / VIDEO_ROWS;

        image (cam, 0, 0);

        // 'activity' array auf 0 setzen
        for (int i=0; i < activity.length; i++) {
          activity[i] = 0;
        }

        // Für jedes Pixel im Videoraster
        for (int i=0; i < cam.pixels.length; i++) {

          // x und y Position des Quadranten berechnen
          int x = (int) ((i % cam.width) / pxPerCol);
          int y = (int) ((i / cam.width) / pxPerRow);

          // Quadranten-Zugehörigkeit des Pixels herausfinden.
          // Später wichtig für das 'activity' array.
          index = y * VIDEO_COLS + x;

          // Farbe an der Position 'i' im Kamerabild
          color col = cam.pixels[i];
          // Die Summe aus allen drei Farbkanälen bilden
          float sum = red (col) + green (col) + blue (col);

          // Farbwertänderung des Pixels bezogen auf alle Bilder errechnen
          float deltaPixel = (buffer1[i] + buffer2[i] + buffer3[i]) / 3 - sum;

          if (deltaPixel < 0) {
            deltaPixel *= -1;
          }

          // Die Änderung auf den Gesamtwert des Quadranten addieren
          activity[index] += deltaPixel;

          // Verschiebe das 'Bildgedächnis' um einen Rutsch nach hinten.
          buffer3[i] = buffer2[i];
          buffer2[i] = buffer1[i];
          buffer1[i] = sum;
        }

        // Für jeden Quadranten
        for (int i=0; i < activity.length; i++) {

          // Durchschnittliche Farbwertänderung berechnen.
          // Mit dem Teilen der Summe durch die Anzahl der Pixel
          activity[i] /= pxPerCol* pxPerRow;

          // Quadrant in das Sketchfenster zeichnen
          stroke (255, 20);
          fill (0, 255, 230, activity[i]);
          rect ((i % VIDEO_COLS) * pxPerCol, (i / VIDEO_COLS) * pxPerRow, pxPerCol, pxPerRow);
        }
      }
    }

i dont know how to get the cam.pixels[] in any way...

im looking forward to any possible solution! thx

martoo6

I can't fully understand you code, but if you are looking to get pixels information from the camera image do it as you would with any other PImage, use get()