The HMT method applied in natural image denoising was thoroughly studied. The HMT method was compared with others under different conditions, such as different complexity of the texture, different type noise and different transform domain. Some key conclusions were obtained.First, the method in transform domain is better than the traditional one which is not in transform domain. Second, the performance of HMT in the DCT domain is similar to that in the wavelet domain. Third, when the noise is white, result of HMT is excellent. However, when the noise is related to the image itself, the performance is determined by the complexity of the texture, as well as the noise density.