An image restoration method includes receiving an externally input image signal, generating a filtered image signal by filtering the input image signal, and generating a restored image signal by calculating a weighted average of the input image signal and the filtered image signal. Such a method may be implemented using an image restoration device including an image filtering unit adapted generated the filtered image signal, and an image mixing unit adapted to generate the restored image signal. More particularly, the restored image signal may be generated using weighting factors calculated based on the input image signal, by calculating a local variance of pixels in the input image signal, and calculating the weighting factor for each of the pixels based on the local variance of each of the pixels.