Learning Processing: A Beginner's Guide to Programming Images ...

286 Learning Processing
fi g. 16.6
Example 16-8: Brightness mirror
// Each pixel from the video source is drawn as a
// rectangle with size based on brightness.
import processing.video.*;
// Size of each cell in the grid
int videoScale = 10;
// Number of columns and rows in our system
int cols, rows;
// Variable for capture device
Capture video;
void setup() {
size(640,480);
// Initialize columns and rows
cols = width/videoScale;
rows = height/videoScale;
smooth();
// Construct the Capture object
video = new Capture(this,cols,rows,15);
}
void draw() {
if (video.available()) {
video.read();
}
background(0);
video.loadPixels();
// Begin loop for columns
for (int i = 0; i � cols; i + + ) { In order to mirror the image, the column
// Begin loop for rows
is reversed with the following formula:
for (int j = 0; j � rows; j + + ) {
// Where are we, pixel-wise?
mirrored column � width – column – 1
int x = i*videoScale;
int y = j*videoScale;
// Reversing x to mirror the image
int loc = (video.width – i – 1) + j*video.width;