PImage img; float offset = 0; float easing = 0.05; 
void setup() { size(640, 360); 
img = loadImage("moonwalk.jpg"); // Load an image into the program 
} 
void draw() { image(img, 0, 0); // Display at full opacity 
float dx = (mouseX-img.width/2) - offset; offset += dx * easing; 
tint(255, 126); // Display at half opacity 
image(img, offset, 0); }