It is difficult to do the postprocessing and the quality assessment of restoration image because of the ringing effect.

This algorithm makes use of lowpass filter and coring circuit to suppress small noise; utilizes adaptive clamping to eliminate ringing effect and “wrong colours”.

WT5”BZ]Based on the compressing algorithm of the coefficient quantization in DCT domain,such as MPEG,JPEG,etc ,as the code rate becomes low,the quantization also becomes more and more rough,such defects as block effect,ring effect and visual dimness come into being after image is remade.

Researching into better restoration algorithms for engineering application, suppressing ring effect in restored image, and restoration algorithm realized with hardware platform, are main problems to be solved.

This paper introduces the concept of the cask effect, and applies it into the library, analyzes on the short planks existing in the library, and advances some solving methods.

The recent ten years witnessed a rapid development in China\'s higher vocational education,in the mean time,the phenomenon of "cask effect" also become prominent in the development of higher vocational colleges in China,which has severely affected the educational quality and the coordinated development of the scale and quality of these colleges.