Patent ID: 8750639

Claim:
A computer-implemented method comprising: receiving an image having an initial resolution; automatically calculating a sharpening amount based on the image by utilizing at least one calculated statistical deviation of a histogram of the image at the initial resolution and at least one calculated statistical deviation of a histogram of the image at a second resolution; applying an unsharp mask filter to the image, the unsharp mask filter employing the sharpening amount and being represented by an expression X′=AF ( X−G ( X ))+ X where X′ is an adjusted value of a pixel in the image, X is a value of the pixel in the image before sharpening, A is the sharpening amount, and G(X) is a result of a convolution of X with a Gaussian kernel G with a standard deviation of one pixel, and where F ⁡ ( x ) = x ⁢ ⁢ if ⁢ ⁢  x  ≥ τ ⁢ ⁢ and ⁢ ⁢ F ⁡ ( x ) = x 2 τ ⁢ ⁢ otherwise where τ is a positive threshold; and outputting a sharpened image relative to the image received.