Method and system for denoising noise image

The invention discloses a method for denoising a noise image, which comprises the following steps: shearing the input noise image to acquire a sheared image; sparsely decomposing the sheared image by a wavelet-based Contourlet conversion to acquire low-frequency sub-images and high-frequency sub-images, and denoising each high-frequency sub-image to acquire a denoised high-frequency sub-image; and performing a wavelet-based Contourlet reverse conversion on the low-frequency sub-images and the denoised high-frequency sub-images, and performing reverse shearing operation with the same shearing amplitude on the low-frequency sub-images and the denoised high-frequency sub-images. The invention also discloses a system for denoising the noise image. The method and the system of the invention effectively decrease noise signals in the image, effectively keep detail information of the image, greatly improve image denoising effect and improve the quality of the image.