blue book examples

java/examples/Books/Processing Handbook/Extensions/Vision/_04/_04.pde

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+// Tracks the brightest pixel in a live video signal
+import processing.video.*;
+
+Capture video;
+
+void setup() {
+  size(640, 480); // Change size to 320 x 240 if too slow at 640 x 480
+  video = new Capture(this, width, height, 30);
+  noStroke();
+  smooth();
+}
+
+void draw() {
+  if (video.available()) {
+    video.read();
+    image(video, 0, 0, width, height); // Draw the webcam video onto the screen
+    int brightestX = 0; // X-coordinate of the brightest video pixel
+    int brightestY = 0; // Y-coordinate of the brightest video pixel
+    float brightestValue = 0; // Brightness of the brightest video pixel
+    // Search for the brightest pixel: For each row of pixels in the video image and
+    // for each pixel in the yth row, compute each pixel's index in the video
+    video.loadPixels();
+    int index = 0;
+    for (int y = 0; y < video.height; y++) {
+      for (int x = 0; x < video.width; x++) {
+        // Get the color stored in the pixel
+        int pixelValue = video.pixels[index];
+        // Determine the brightness of the pixel
+        float pixelBrightness = brightness(pixelValue);
+        // If that value is brighter than any previous, then store the
+        // brightness of that pixel, as well as its (x,y) location
+        if (pixelBrightness > brightestValue) {
+          brightestValue = pixelBrightness;
+          brightestY = y;
+          brightestX = x;
+        }
+        index++;
+      }
+    }
+    // Draw a large, yellow circle at the brightest pixel
+    fill(255, 204, 0, 128);
+    ellipse(brightestX, brightestY, 200, 200);
+  }
+}