1. An image processing apparatus, comprising: a wavelet transform device for performing wavelet transform on an input image to decompose the input image into a plurality of levels of different scales, each level including a low frequency component and a plurality of high frequency components; a compensation template generating device for generating a compensation template for each level according to the plurality of high frequency components in the level obtained from the wavelet transform, the compensation template reflecting combination features of the plurality of high frequency components of the level; a de-noising device for de-noising the low frequency component of each level, and performing edge compensation on the low frequency component of the level by using the compensation template of the level to acquire a compensated low frequency component; and a wavelet inverse transform device for performing inverse wavelet transform with the compensated low frequency component and the high frequency components of each level, to acquire a de-noised image.