This example is for Processing 3+. If you have a previous version, use the examples included with your software. If you see any errors or have suggestions, please let us know.

Transparency.

Move the pointer left and right across the image to change its position. This program overlays one image over another by modifying the alpha value of the image with the tint() function.


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, 127);  // Display at half opacity
  image(img, offset, 0);
}