1. A method for deblurring a blurry image, the method comprising the step of: estimating a PSF kernel of at a least a portion of the image using a PSF cost function having (i) a first fidelity term that includes a derivative in a first direction, (ii) a first weight for the first fidelity term, (iii) a second fidelity term that includes a derivative in a second direction that is different from the first direction, (iv) a second weight for the second fidelity term, the second weight being different from the first weight, (v) a third fidelity term that includes a derivative in a third direction, and (vi) a third weight for the third fidelity term, wherein the third direction is different from the first direction and the second direction, and wherein the third weight is different from the second weight and the first weight; and deblurring the image utilizing the estimated PSF kernel.