This paper presents a new technique for noise removal in images. It benefits both from the recent advances in waveletbased and variational denoising. Whereas wavelet-based analysis tends to strongly depend on the selected wavelet basis, we propose to combine and fuse several mono-wavelet analysis within a variational framework. The associated energy function involves M-estimator in order to guarantee the robustness to outliers and to preserve image structures (edges, ridges,...). An experimental evaluation for a Gaussian additive noise validates the proposed approach and an application to speckle removal in sonar sea-bed images highlights the interest of this approach for real images.