HTML Canvas相关

1 将Image画到canvas上面

function convertImageToCanvas(image) {
	var canvas = document.createElement("canvas");
	canvas.width = image.width;
	canvas.height = image.height;
	canvas.getContext("2d").drawImage(image, 0, 0);

	return canvas;
}

2 将Canvas的内容转为png图片

function convertCanvasToImage(canvas) {
	var image = new Image();
	image.src = canvas.toDataURL("image/png");
	return image;
}