2101centroidfinal

// computer vision test

// hipster burglar alarm

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var capture, previous, diff;

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var thresh = 30;

var camerax = 64;

var cameray = 64;

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// centroid values:

var cx = 0;

var cy = 0;

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function preload() {

}

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function setup() {

  createCanvas(windowWidth, windowHeight);

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  capture = createCapture(VIDEO); // this opens up the camera

  pixelDensity(1); // turns off oversampling ("retina display")

  capture.size(camerax, cameray); // this is in pixels

  capture.hide(); // telling the browser to hide the camera so we can draw it ourselves

  previous = createImage(camerax, cameray); // create an empty picture

  diff = createImage(camerax, cameray); // create an empty picture

}

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function draw() {

  //thresh = mouseY/height * 255; // uncomment this for playing with the threshold

  background(0);

  capture.loadPixels();

  previous.loadPixels();

  diff.loadPixels();

  noSmooth(); // this makes everything not interpolate

  var x, y, p;

  var rsum=0; // running sum

  var avgx = 0; // average x value

  var avgy = 0; // average y value

  var numpix = capture.pixels.length/4;

  for(let i = 0;i<capture.pixels.length;i+=4)

  {

    let avg = (abs(capture.pixels[i]-previous.pixels[i]) + abs(capture.pixels[i+1]-previous.pixels[i+1]) + abs(capture.pixels[i+2]-previous.pixels[i+2]))/3;

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    let bval = (avg>thresh); // binary value

    rsum+=bval; // add to running sum

    p = floor(i/4);

    x = p%capture.width;

    y = floor(p/capture.width);

    avgx+= bval?x:0;

    avgy+= bval?y:0;

    // just for show:

    diff.pixels[i]=diff.pixels[i+1]=diff.pixels[i+2]=bval*255;

    diff.pixels[i+3]=255;

  }

  if(rsum>0) cx = avgx/rsum; // centroidx

  if(rsum>0) cy = avgy/rsum; // centroidy

  diff.updatePixels();

  for(let i = 0;i<capture.pixels.length;i++)

  {

    previous.pixels[i] = capture.pixels[i];

  }

  previous.updatePixels();

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  image(capture, 0, 0, width/2, height/2);

  image(diff, width/2, 0, width/2, height/2);

  let cxx = map(cx, 0, capture.width, width/2, width);

  let cyy = map(cy, 0, capture.height, 0, height/2);;

  fill(255,0,0);

  ellipse(cxx, cyy, 80, 80);

  textSize(80);

  fill(255);

  text(cx, width/2, height/2 + 80);

  text(cy, width/2, height/2 + 160);

  text(rsum, width/2, height/2 + 240);

  //text(numpix, width/2, height/2 + 320);

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}

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