1. A computer-implemented method for enhancing a blurred image (G 0 ) comprising a plurality of pixel values, the method comprising: generating a standard gray low-resolution image (G 1 ) by convoluting the plurality of pixel values of the blurred image (G 0 ) with a Gaussian low-pass filter; extracting one or more high-frequency components (L 0 ) from the standard gray low-resolution image (G 1 ); obtaining one or more higher-frequency nonlinear components (L −1 ) by approximating the one or more high-frequency components (L 0 ), wherein obtaining one or more higher-frequency nonlinear components (L −1 ) by approximating the one or more high-frequency components (L 0 ) comprises: multiplying a fourth derivative of the one or more high-frequency components (L 0 ) with a weighting factor (k 2 ); and adding the one or more high-frequency components to multiplication of the fourth derivative of the one or more high-frequency components (L 0 ) and the weighting factor (k 2 ); and adding the one or more higher-frequency nonlinear components (L −1 ) to the blurred image (G 0 ) to generate an enhanced image (G −1 ).