Hi there,

fairly new to Processing and programming, newbie question ahead:

I am trying to make a little sketch using openCV that does the following:
loads an image to memory
looks through all the pixels
based on the position of each face detected by openCV,
it draws the image from the picture, in a circle with a radius of brightness depending on the distance between the pixel and the center of the rectangle of the face.

My problem is: the code I use feels very slow and non-optimal. I am using algorithms learnt from Shiffman's book, as well as from the openCV examples. I guess a more experienced programmer can help me either optimizing or telling me that this is impossible, and I'd rather do something else :)

Anyhow, here's the code, and thanks in advance!

Code:

import hypermedia.video.*;
OpenCV opencv;
PImage img;
int centerX, centerY, lenX, lenY;

void setup() {
  img = loadImage( "night.jpeg" );
  size(img.width, img.height);
  opencv = new OpenCV(this);
  opencv.capture(width, height);
  opencv.cascade(OpenCV.CASCADE_FRONTALFACE_ALT);
}

void draw() 
{
  background(0);

  opencv.read();
  Rectangle [] faces = opencv.detect();

  loadPixels();
  img.loadPixels();


  for(int i = 0; i < faces.length; i++)
  { 
    lenX = faces[i].width/2;
    lenY = faces[i].height/2;
    centerX = faces[i].x + lenX;
    centerY = faces[i].y + lenY;
    for (int x = 0; x < img.width; x++ ) {
      for (int y = 0; y < img.height; y++ ) {

        //pixel location
        int loc = x + y*img.width;

        // getting RGB
        float r = red (img.pixels[loc]);
        float g = green (img.pixels[loc]);
        float b = blue (img.pixels[loc]);

        // lintern effect
        float distance = dist(x,y, centerX,centerY);

        float adjustBrightness = (100-distance)/100;
        r *= adjustBrightness;
        g *= adjustBrightness;
        b *= adjustBrightness;

        // Constrain RGB
        r = constrain(r,0,255);
        g = constrain(g,0,255);
        b = constrain(b,0,255);

        // new color, pixel displayed
        color c = color(r,g,b);
        pixels[loc] = c;

      }

    }
    updatePixels();  
  }
}