@Pitamber で述べたように、ここに convg ライブラリの詳細情報を追加する必要があります - https://code.google.com/p/canvg/
したがって、実際の例は次のようになります
<!--
To change this template, choose Tools | Templates
and open the template in the editor.
-->
<!DOCTYPE html>
<html>
<head>
<title></title>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<script type="text/javascript" src="http://canvg.googlecode.com/svn/trunk/rgbcolor.js"></script>
<script type="text/javascript" src="http://canvg.googlecode.com/svn/trunk/StackBlur.js"></script>
<script type="text/javascript" src="http://canvg.googlecode.com/svn/trunk/canvg.js"></script>
<script type="text/javascript" src="https://www.google.com/jsapi"></script>
</head>
<body>
<div id="img_div" style="position: fixed; top: 0; right: 0; z-index: 10; border: 1px solid #b9b9b9">
Image will be placed here
</div>
<button onclick="saveAsImg(document.getElementById('pie_div'));">Save as PNG Image</button>
<button onclick="toImg(document.getElementById('pie_div'), document.getElementById('img_div'));">Convert to image</button>
<div id="pie_div"></div>
</body>
<script>
function getImgData(chartContainer) {
var chartArea = chartContainer.getElementsByTagName('svg')[0].parentNode;
var svg = chartArea.innerHTML;
var doc = chartContainer.ownerDocument;
var canvas = doc.createElement('canvas');
canvas.setAttribute('width', chartArea.offsetWidth);
canvas.setAttribute('height', chartArea.offsetHeight);
canvas.setAttribute(
'style',
'position: absolute; ' +
'top: ' + (-chartArea.offsetHeight * 2) + 'px;' +
'left: ' + (-chartArea.offsetWidth * 2) + 'px;');
doc.body.appendChild(canvas);
canvg(canvas, svg);
var imgData = canvas.toDataURL('image/png');
canvas.parentNode.removeChild(canvas);
return imgData;
}
function saveAsImg(chartContainer) {
var imgData = getImgData(chartContainer);
// Replacing the mime-type will force the browser to trigger a download
// rather than displaying the image in the browser window.
window.location = imgData.replace('image/png', 'image/octet-stream');
}
function toImg(chartContainer, imgContainer) {
var doc = chartContainer.ownerDocument;
var img = doc.createElement('img');
img.src = getImgData(chartContainer);
while (imgContainer.firstChild) {
imgContainer.removeChild(imgContainer.firstChild);
}
imgContainer.appendChild(img);
}
google.load('visualization', '1', {packages: ['corechart', 'treemap', 'geochart']});
google.setOnLoadCallback(drawChart);
function drawChart() {
// Pie chart
var data = new google.visualization.DataTable();
data.addColumn('string', 'Task');
data.addColumn('number', 'Hours per Day');
data.addRows(5);
data.setValue(0, 0, 'Work');
data.setValue(0, 1, 11);
data.setValue(1, 0, 'Eat');
data.setValue(1, 1, 2);
data.setValue(2, 0, 'Commute');
data.setValue(2, 1, 2);
data.setValue(3, 0, 'Watch TV');
data.setValue(3, 1, 2);
data.setValue(4, 0, 'Sleep');
data.setValue(4, 1, 7);
var chart = new google.visualization.PieChart(document.getElementById('pie_div'));
chart.draw(data, {width: 450, height: 300, title: 'My Daily Activities'});
}
</script>
</html>