i did this to get the color of a point in the webcam capture. It works well, but when i use the imageadjuster lib. it does not.
You can define the color by clicking on the video.
I split the video in two parts. the left part is adjusted, the right is not.
The selected color will be shown as a black overlay.

I hope you can help me to fix the problem.

Code:

import processing.video.*;
import imageadjuster.*;

ImageAdjuster adjust = new ImageAdjuster(this);
Capture video;
float RED=400;
float GREEN=400;
float BLUE=400;
color a1;
float threshold=5;

void setup() {
  size(320,240);
  video = new Capture(this, width, height, 30);
}

void draw() {
  if (video.available()) {
    video.read();
    image(video, 0, 0, width, height); // Draw the webcam video onto the screen
    video.loadPixels();

    //Problem starts here:
    adjust.contrast(g, 0, 0, width/2, height, 3.0f);


    for(int j=0; j<video.height; j++){
	for(int i=0; i<video.width; i++){
	  int num = (j*video.width)+i;
	  if( (abs(red(video.pixels[num]) - RED) <=threshold) && (abs(green(video.pixels[num]) - GREEN) <=threshold) && (abs(blue(video.pixels[num]) - BLUE)<=threshold)){
	    stroke(0);
	    point(i,j);
	  }
	}
    }
  }
}

void mousePressed() {
  a1=get(mouseX, mouseY);
  RED=red(a1);
  GREEN=green(a1);
  BLUE=blue(a1);

}

void keyPressed() 
{
  if (key == 'A' || key == 'a') {
    threshold++;
  }
  else if ((key == 'y' || key == 'Y')&& threshold>0) {
    threshold--;
  }
  println("threshold= "+threshold);
}