Spatial averaging techniques, such as pixel binning and the 2D Gaussian smoothing, are often used to moderately reduce noise and were empirically shown to improve the performance of wPCA on noisy EDX spectral imaging data . Such approaches down-sample the spatial resolution by implicitly assuming that each component is distributed uniformly over certain regions and that the number of components does not change by the down-sampling. However, the down-sampling could mix spectra from different components in an irreversible way. It is thus considered useful to retain the spatial resolution of observation in every step of the analysis, e.g., when observing nanoparticles to reveal chemical reactions . With this motivation, we aim to develop a preliminary noise reduction method without changing the spatial resolution.