Automatic detection of fluorescent flicker in video images

A method for detecting the presence of flicker in video images includes obtaining luminance data from sampled image fields and analyzing the luminance data to obtain a digital number characterizing the brightness of the luminance data. Frequency analysis is performed on a time-series of digital numbers collected over multiple sampled image fields to provide a signal indicative of the spectral energy at a flicker frequency band and a signal indicative of the spectral energy at a non-flicker frequency band. A ratio of the two spectral energy signals is computed as the flicker detect indicator. Multiple flicker detect indicators are accumulated to generate a flicker present signal. In one embodiment, the flicker detect indicator is accumulated only when the ratio has a value greater than a first threshold and the flicker present signal is asserted only when the number of flicker detect indicator signals accumulated exceeds an entry value.