A method and an apparatus for estimating an image fuzziness are provided. The method may comprise: acquiring an image; obtaining a multi-scale representation of the image by performing a multi-scale transform on the image; calculating gradients of the image and a normalized histogram of the gradients at each scale based on the multi-scale representation; calculating error vectors between the normalized histogram of gradients at each scale and a normalized original histogram of gradients of the image; performing a weighted summing on the error vectors by using respective weights to obtain a summed result, wherein the weights are determined based on a reciprocal of the sums of squares of the gradients of the image at each scale; estimating the ambiguity of the image based on the summed result.