let gridSize = 8; // Controls the spacing of the dots

let brightnessOffset = 0; // Adjust brightness (-255 to 255)

let contrastFactor = 1;   // Adjust contrast (0 to any positive number, 1 means no change)

​

function setup() {

  createCanvas(640, 480);

  video = createCapture(VIDEO);

  video.size(width / gridSize, height / gridSize); // Resize video to match grid size

  video.hide();

  noStroke();

  // Slider for brightness adjustment

  createP('Brightness');

  brightnessSlider = createSlider(-255, 255, 0); // Range: -255 (darken) to +255 (brighten)

  // Slider for contrast adjustment

  createP('Contrast');

  contrastSlider = createSlider(0, 3, 1, 0.1); // Range: 0 (flat contrast) to 3 (high contrast)

}

​

function draw() {

  background(255);

  // Update brightness and contrast values from sliders

  brightnessOffset = brightnessSlider.value();

  contrastFactor = contrastSlider.value();

  video.loadPixels();

  for (let y = 0; y < video.height; y++) {

    for (let x = 0; x < video.width; x++) {

      let index = (x + y * video.width) * 4;

      // Get pixel color values

      let r = video.pixels[index];

      let g = video.pixels[index + 1];

      let b = video.pixels[index + 2];

      // Convert pixel to grayscale

      let grayscale = 0.299 * r + 0.587 * g + 0.114 * b;

      // Apply brightness adjustment

      grayscale = grayscale + brightnessOffset;

      grayscale = constrain(grayscale, 0, 255); // Ensure the value stays within 0-255

      // Apply contrast adjustment

      grayscale = map(grayscale, 0, 255, 128 - 128 * contrastFactor, 128 + 128 * contrastFactor);

      // Map grayscale to dot size (smaller for lighter, larger for darker)

      // play with this constraint to further adjust point sizing

      // grayscale = constrain(grayscale, 0, 255); // Ensure the value stays within 0-255

      // Binary threshold for 2-color halftone (if grayscale < 128, it becomes black; otherwise white)

      let isDark = grayscale < 128;

      let fillA = color(0,0,0) //black

      let fillB = color(255,255,255) //white

      // let fillA = color(255,0,0) //red

      // let fillB = color(0,255,0) //green

      let fillColor = isDark ? fillA : fillB;

 // Black for dark, white for light

      let dotSize = map(grayscale, 0, 255, gridSize, 0.125); // Larger dots for darker areas

      // Set fill to either black or white

      fill(fillColor);

      // Draw a circle at the position of the pixel

      ellipse(x * gridSize, y * gridSize, dotSize, dotSize);

    }

  }

}

​

function keyPressed() {

  if (key === 's') {

    saveGif('halftone', 3);

  }

}

​