US Patent 7855806 Banding profile estimator using multiple sampling intervals

A method of integrating multiple sampling interval image data with timing information from a defect once-around sensor and the machine page sync signals to estimate a banding profile. By augmenting the sampling interval data with the timing data, proper phasing of each frequency over each sampling interval can be maintained. Specifically, when the data over the multiple intervals is taken, the defect source once-around signal and the page sync signals are also recorded. The combination of this information allows the algorithm to extract phase and amplitude information of banding defects from the sampling intervals using a new matched-filter based parameter estimation algorithm. Estimated banding profiles are then generated from the known frequencies, and the estimated amplitude and phase values.