Patent ID: 8218086

Claim:
A method of pre-processing video data to detect flashes, comprising: calculating a normalized difference index value for a Luminance [Y] component of the video data; calculating a normalized difference index value for Chrominance [U and V] components of the video data; calculating a normalized luminance [Y] mean gradient index for the video data, wherein the normalized luminance [Y] mean gradient index is calculated by: G t = ∇ M ⁡ ( t ) V max = ( m t - m t - 1 ) V max wherein m t is the value mean of a luminance picture at time t, V max is the maximal value of luminance pixels in a picture in the video data, G t is the normalized luminance [Y] mean gradient index, and ΔM(t) is the difference between m t and m t−1 ; and providing an indication that a flash has been detected when all the following conditions are satisfied: the normalized difference index value for the Luminance [Y] component is greater than a first predetermined threshold (T Y ); the normalized difference index value for the Chrominance [U and V] components is less than a second predetermined threshold (T C ); and a difference between the normalized difference index value for the Chrominance [U and V] components and the normalized luminance [Y] mean gradient index is less than or equal to a third pre-determined threshold (T F ).