code: function parseImageOption(){ // (type,quality,option)のはず
  	var imageopt = {};
  	var type = pzpr.Candle.current;
  	var cellsize = null, bgcolor = null, quality = null;
  	for(var i=0;i<arguments.length;i++){
  		var argv = arguments[i];
  		switch(typeof argv){
  			case 'string':
  				type = argv;
  				break;
  			case 'number':
  				if(argv>1.01){ cellsize = argv;}else{ quality = argv;}
  				break;
  			case 'object':
  				if('cellsize' in argv){ cellsize = argv.cellsize;}
  				if('bgcolor'  in argv){ bgcolor  = argv.bgcolor;}
  				break;
  		}
  	}
  	
  	imageopt.type = ((type||pzpr.Candle.current).match(/svg/)?'svg':'canvas');
  	imageopt.mimetype = (imageopt.type!=='svg' ? 'image/'+type : 'image/svg+xml');
  	if(quality!==null && quality!==void 0){ imageopt.quality = quality;}
  	
  	if(cellsize!==null){ imageopt.cellsize = cellsize;}
  	if(bgcolor !==null){ imageopt.bgcolor  = bgcolor;}
  	
  	return imageopt;
  }
docs: --------------------------------------------------------------------------- generateLocalCanvas()  toDataURL, toBlobの入力オプション解析処理 ---------------------------------------------------------------------------