private String getSizeStr(PointCloud2 cloud)
	{
		String typeStr = new String("SIZE");
		for(PointField field: cloud.fields){
			switch(field.datatype){
			case(1):
			case(2):
				typeStr = typeStr + " 1";
				break;
			case(3):
			case(4):
				typeStr = typeStr + " 2";
				break;
			case(5):
			case(6):
			case(7):
			case(8):
				typeStr = typeStr + " 4";
				break;
			}
		}
		return typeStr;
			
		
	}