3D Wavelet Subbands Mixing for Image Denoising

Figure 3

Workflow. First, the noisy image I is denoised with two sets of filtering parameters 𝑆_𝑢 and 𝑆_𝑜. Then, 𝐼_𝑢 and 𝐼_𝑜 are decomposed into low- and high-frequency subbands by 3D DWT. The four lowest frequency subbands of 𝐼_𝑢 (i.e., LLL₁, LLH₁, LHL₁, and HLL₁) are mixed with the four highest-frequency subbands of 𝐼_𝑜 (i.e., LHH₁, HLH₁, HHL₁, and HHH₁). Finally, the result image is obtained by inverse 3D DWT of the selected subbands.