1. A method for image noise correction, the method comprising, for at least one target pixel having a defined pixel value: for each pixel in a window of pixels surrounding the target pixel, estimating a weighting factor for that pixel, the weighting factor being based on the value of the target pixel and the value of at least one pixel within the window; calculating an average of pixel values for the pixels in the window, the calculating of the average of pixel values comprising weighting the value of each pixel within the window by the weighting factor that was estimated for that pixel; and assigning to the target pixel a new value that is based on the average of pixel values that was calculated, wherein the estimating of the weighting factor for each pixel in the window comprises determining a difference between the value of that pixel and the value of the target pixel.