Processing: Creative Coding and Computational Art

simple-looking paint bucket tool in your favorite paint program. You don’t need to use bitwise
operations, as Processing has the component property functions red(), green(),
blue(), and alpha(); but there may be times when the bitwise operations will really come
in handy. Here’s a final Processing sketch that illustrates one of the things you can do with
bitwise operations (shown in Figure B-7). (Please note this example requires the use of an
external image, which needs to be added to the sketch’s data directory.)
/*
Color Variations Filter Using
Bitwise Operations
Ira Greenberg, November 11, 2005
revised: April 3, 2007
*/
/*change display size to accommodate
the size of your image */
size(360, 600);
/*remember to add an image into
the sketch data directory before
using loadImage() and also to update
the name of the image below. */
PImage img = loadImage("robin_and_sophie.jpg");
image(img, 0, 0);
// pixel array
int[]pxls = new int[width*height];
// holds shifted colors
color[]newCol = new int[width*height];
// keep track of pixels
int pxlCounter = 0;
/* loop gets color components out
of color integer using bitwise operators
and shifts color components before
rebuilding pixel array- effect is similar
to Photoshop's variations filter */
for (int i=0; i 16 & 0xFF;
int g = pxls[pxlCounter] >> 8 & 0xFF;
int b = pxls[pxlCounter] & 0xFF;
int a = pxls[pxlCounter] >> 24 & 0xFF;
/* conditionals check where we are in the image
min() functions keep color component values in
range 0-255 to avoid psychadelic artifacting */
//left column, top row(red+)
if (i