hi all

i have some code that is meant to save and draw an image from a cam as bg, then draw pixelated versions of anything that moves through the bg on top of it ( so people walking through a space would look censored for example). the prob i seem to have is that both my matrices 'bg' and 'in' which come from the same cam are always the same. even though bg should only be updated when a key is pressed. i have had no luck opening 2 capture objects from the same cam or just copying the feed into the bg image with bg = in; i think the answer might be in copying the array as mentioned here:
http://processing.org/discourse/yabb_beta/YaBB.cgi?board=VideoCamera;action=display;num=1123580926

but i'm not sure how to implement this.

any help would be greatly appreciated - here's my code:

****************************

import processing.video.*;
Capture myCapture;
PImage bg;
PImage in;
//distance on colour for section to be pixelated
float thresh = 13;
//size of each rect
int cellsize = 8;
//number of columns and rows in our system
int COLS, ROWS;

void setup()
{
 size(320, 240);
 framerate(12);
 COLS = width/cellsize;
 ROWS = height/cellsize;
 //colorMode(RGB,255,255,255,100);
 rectMode(CENTER);
 noStroke();
 
 //println(Capture.list());
 String s = "DV Video";
 myCapture = new Capture(this, s, width, height, 12);
 
 myCapture.read();
 bg = myCapture;
 
}

void draw()
{
 image(bg,0,0); //draws bg from keypress
 pixelate();

}

void pixelate() {

 myCapture.read();
 in = myCapture;

 //begin loop for columns
 for ( int i = 0; i < COLS;i++) {
   //begin loop for rows
   for ( int j = 0; j < ROWS;j++) {
     //save transformation matrix
     pushMatrix();
     //calculate x and y location
     int x = i*cellsize + cellsize/2;
     int y = j*cellsize + cellsize/2;
     int loc = x + y*width;
     loc = constrain(loc,0,in.pixels.length-1);
     //get colours from feed
     float R2 = red(in.pixels[loc]);
     float G2 = green(in.pixels[loc]);
     float B2 = blue(in.pixels[loc]);
     //get colours from bg
     float R1 = red(bg.pixels[loc]);
     float G1 = green(bg.pixels[loc]);
     float B1 = blue(bg.pixels[loc]);
     
     translate(x,y);      
     float d = dist(R2,G2,B2,R1,G1,B1);

     if ( d > thresh ) {
     //draw rect:
     fill(R2,G2,B2);
     rect(0,0,cellsize,cellsize);  
     }
     //restore transformation matrix
     popMatrix();
   }
 }
}


void keyPressed() {
 myCapture.read();
 bg = myCapture;
 println("new bg");
}