Various embodiments describe image sharpening techniques that automatically estimate a sharpening amount for an unsharp mask filter for image enhancement based upon a statistical correlation between detail coefficients at a first resolution and at a second resolution. In various embodiments, statistical deviation of absolute values of detail coefficients for both the image at full resolution and the image downsampled by a pre-determined factor, e.g. a factor of two (half resolution), are retrieved. In various embodiments, the statistical deviation is retrieved for a histogram of the image at the first resolution and a histogram of the image at the second resolution. The linear model between the statistical deviation of detail coefficients at the first resolution and the second resolution is used to calculate the sharpening amount and the unsharp mask filter is applied to the image to produce a sharpened image.