Code

import processing.video.*;
Capture video;
void captureEvent(Capture video) {
video.read();
}

void setup() {
size(1280, 960);
video = new Capture(this, 640, 480);
video.start();
}

void draw() {
background(0);

fill(255,0,0,255);
rect(0,0,1280,200);
fill(0,0,255);
rect(0,760,1280,200);

image(video, 0, 0);
tint(255,0,0,255);
image(video, 640, 480);
tint(0,0,255);

loadPixels();
video.loadPixels();

for (int x = 0; x < video.width; x++) {
for (int y = 0; y < video.height; y++) {
int loc = x + y * video.width;

float r = red (video.pixels[loc]);
float g = green(video.pixels[loc]);
float b = blue (video.pixels[loc]);

float d = dist(x, y, mouseX, mouseY);
float adjustbrightness = map(d, 0, 100, 4, 0);
r *= adjustbrightness;
g *= adjustbrightness;
b *= adjustbrightness;

r = constrain(r, 0,0);
g = constrain(g, 0, 255);
b = constrain(b, 0, 255);

color c = color(r, g, b);
pixels[loc] = c;
}
}

updatePixels();

}