将一幅图像先进行分成8X8块，然后对每个8X8块进行DCT变化，最后将变换后的图片进行分层，重新显示-Will an image to 8 X8 into pieces, then to every 8 X8 block DCT change, finally will transform the images after the layered, displayed again

读入一个图片，然后调用readblock读取一个8X8块，观察图片的RGB分量-Read in a picture, and then calling readblock read a 8 X8 piece, observe picture RGB component