Patent ID: 7092579
Filing Date: 2006-08-15
Classification: G06T

Abstract:
1. A method of estimating the noise in a digital image for use in subsequent image processing, comprising the steps of: a) receiving a source digital image having a plurality of pixels; b) selecting a pixel of interest; c) providing a plurality of orientations for the pixel of interest; d) using gradient analysis on the source digital image and the plurality of orientations to select the most suitable orientation for estimating noise for the pixel of interest by calculating two or more directional intensity gradient values for the pixel of interest wherein each directional intensity gradient value corresponds to a different spatial orientation about the pixel of interest; e) using the selected orientation in the pixel of interest to determine a noise-free pixel estimate for the pixel of interest; and f) repeating steps b)–e) for other pixels of interest and using the noise-free pixel estimates to calculate a noise characteristic value representing the noise estimate for the source digital image.