The invention discloses an improved BM3D
image denoising method based on multi-element fusion block similarity measurement. According to the method,
wavelet decomposition is carried out on a
noise image, a
noise standard deviation is stably estimated on a highest-frequency sub-band, BM3D parameters are initialized, in a basic
estimation stage,
pixel intensity,
local variance and gradient difference are fused to construct block similarity measurement, similar block matching grouping and three-dimensional
block group construction are realized, and the method has the advantages of being high in robustness and high in robustness. And in a final
estimation stage, a basic
estimation image is obtained through three-dimensional collaborative hard threshold filtering and weighted aggregation, in the final estimation stage, secondary matching is guided by the basic estimation image, a three-dimensional
block group is constructed again, a structure and texture adjustment factor is introduced to form an adaptive Wiener coefficient for Wiener
collaborative filtering, and finally, a target de-noised image is output through weighted aggregation. In the whole process, the phenomena of mismatching and over-
smoothing of a traditional BM3
D algorithm under the condition of high
noise can be reduced, the edge and texture detail keeping capability is enhanced, and the denoising quality of a noise image is improved.