private String convert2Number (List<BufferedImage> images) throws IOException
	{
		StringBuffer buffer = new StringBuffer (images.size());

		for (BufferedImage x:images)
		{
			ByteArrayOutputStream out = new ByteArrayOutputStream();
			ImageIO.write(x, "BMP", out);
			byte b[] = out.toByteArray();
			out.flush();
			out.close();
			for (int i=0; i<NumberCode.numbers.length; ++i)
			{
				//定义index为字节相异个数;
				int index=0;
				for (int j=0; j<b.length; ++j)
				{
					if (b[j]!=NumberCode.numbers[i][j])
						index+=1;
				}
				//容错率;
				if(index<30)
				{	
					buffer.append (i);
					break;
				}

			}
		
		}	
		return buffer.toString();
	}