The objects' spectrum is often contaminated by noise when it is collected in the open air.According to the principle of the spectrum collection,the noise was considered as one kind of multiplicative compound noise.By theoretical derivation,the combination of logarithm transform and wavelet transform was introduced into noise reduction.Multiplicative noise simulation test was carried out.And the results show that the spatial correlation algorithm is best suited for spectral data denoising,modulus maxima algo...