var qr = new JSQR();                              // Initialize a new JSQR object
var code = new qr.Code();                         // Initialize a new Code object

code.encodeMode = code.ENCODE_MODE.BYTE;          // Set the code data type
code.version = code.DEFAULT;                      // Set the code version
                                                  //   (DEFAULT = use the smallest possible version)
code.errorCorrection = code.ERROR_CORRECTION.H;   // Set the error correction level (H = High)

var input = new qr.Input();                       // Initialize a new Input object
input.dataType = input.DATA_TYPE.TEXT;            // Specify the data type of 'data'
                                                  //   Here, 'data' contains only text
input.data = 'http://www.jsqr.de';                // Specify the data which should be encoded

var matrix = new qr.Matrix(input, code);          // Initialize a new Matrix object using the input
                                                  //   and code, defined above
                                                  //   At this point, the QR Code get generated

matrix.scale = 4;                                 // Specify the scaling for graphic output
matrix.margin = 2;                                // Specify the margin for graphic output

var canvas = document.createElement('canvas');    // Create a new Canvas element
canvas.setAttribute('width', matrix.pixelWidth);  // Set the canvas width to the size of the QR code
canvas.setAttribute('height', matrix.pixelWidth); // Set the canvas height to the size of the QR code
canvas.getContext('2d').fillStyle = 'rgb(0,0,0)'; // Set the foreground color of the canvas to black
matrix.draw(canvas, 0, 0);                        // Draw the QR code into the canvas
                                                  //   at position 0 (left), 0 (top)
document.body.appendChild(canvas);                // Append the canvas element to the documents body