渐进式编码，JPEG 2000标准的另一个特点，就是双…

代码说明：

Progressive coding, another feature of the JPEG 2000 standard, means that the bit stream can be coded in such a way as to contain less-detailed information at the beginning of the stream and more detailed information as the stream progresses. This makes it ideal for Internet/network applications―especially with large images and low bandwidths―as the image can be seen instantly on the decoding side, even with low-speed networks or image databases. The lower subbands are shown first, and more detail is added as time progresses. The picture thus becomes sharper and more detailed over time, and the entire image does not have to be downloaded before it can be seen