Patent ID: 6101278
Filing Date: 2000-08-08
Classification: H04N

Abstract:
A method of extracting coding parameters from uncoded video data, where the coding parameters correspond substantially to coding parameters used in a coding operation that was previously performed on the video data, the method comprising the steps of:generating a histogram for at least one AC frequency band in the uncoded video data;calculating a correlation function for the histogram;identifying a maximum value of the correlation function; anddetermining a coding parameter for the at least one AC frequency band using the maximum value of the correlation function:wherein the step of calculating the correlation function includes:identifying a predetermined number of peaks in the histogram of the uncoded video data; andcalculating (i) a standard auto-correlation function for the histogram in a case that the number of peaks is less than or equal to a predetermined value, where the standard auto-correlation function is performed for all identified peaks, and (ii) a modified auto-correlation function for the histogram in a case that the number of peaks is greater than the predetermined value, where the modified auto-correlation function is performed for less than all of the identified peaks.