[PLUGIN] Canvas

	// called when loading the full state of the game
	instanceProto.loadFromJSON = function (o)
	{
        var canvasWidth = this.canvas.width = o["canvas_w"];
        var canvasHeight = this.canvas.height = o["canvas_h"];
        
        var img_data = this.ctx.createImageData(canvasWidth, canvasHeight);
        var data = img_data.data;
        var cnt = data.length;
        for(var i=0; i<=cnt; i++)        
            data[i] =o["image"][i];   
        
        this.ctx.putImageData(img_data, 0, 0);
	};[/code:31ka48yz]

	// called when loading the full state of the game
	instanceProto.loadFromJSON = function (o)
	{
        var canvasWidth = this.canvas.width = o["canvas_w"];
        var canvasHeight = this.canvas.height = o["canvas_h"];
        var data = this.ctx.getImageData(0,0,this.canvas.width,this.canvas.height).data;
        for (var y = 0; y < canvasHeight; ++y) {
            for (var x = 0; x < canvasWidth; ++x) {
                var index = (y * canvasWidth + x)*4;
                for (var c = 0; c < 4; ++c)
                data[index+c] = o["image"][index+c];
            }
        }
		// load from the state previously saved by saveToJSON
		// 'o' provides the same object that you saved, e.g.
		// this.myValue = o["myValue"];
		// note you MUST use double-quote syntax (e.g. o["property"]) to prevent
		// Closure Compiler renaming and breaking the save format
	};[/code:26psdbe6]

"ctx.getImageData" only copy image data, not get the reference. Any modification of this data array would not affect the canvas image.
[code:26psdbe6]var data = this.ctx.getImageData(0,0,this.canvas.width,this.canvas.height).data;[/code:26psdbe6]

The solution of change the image of this canvas is using "ctx.putImageData", imo. Since this method needs an image data parameter, I use "ctx.createImageData" to create a new one, then fill it by saving data. Finally put this new image data back by "ctx.putImageData",