Patent ID: 7995137

Claim:
An exposure compensation method for a digital image, comprising the steps of: deriving initial edge energy from luminance values for pixels in the digital image having an initial exposure value, wherein edge energy is calculated by E ⁢ ⁢ E = Average ⁡ ( ∑ j = 1 n ⁢ ⁢ Edge ⁢ ⁢ Value j 2 × W j ) where EE is the edge energy, Average represents an average operation, n is the number of the pixels, W j is a weight and EdgeValue j is obtained by adding the luminance value of a center pixel X j multiplied by a center weight to the luminance values of pixels adjacent to the center pixel X j respectively multiplied by corresponding neighboring weights; obtaining maximum edge energy and an optimal exposure compensation value corresponding to the maximum edge energy; confirming whether a difference between the maximum edge energy and the initial edge energy is larger than a threshold value; and setting a current exposure value to the initial exposure value compensated by the optimal exposure compensation value if the confirmation is affirmative.