Patent ID: 6108054
Filing Date: 2000-08-22
Classification: H04N

Abstract:
Method for obtaining correction values for video lines of a video frame, in particular for convergence setting in a video projection device, comprising the steps of:defining interpolation intervals between each adjacent pair of a plurality of original values being distributed in the form of a grid over the screen area of the video projection device;calculating correction values for the video lines at least in part by means of interpolation within each said interpolation interval;calculating a respective set of two intermediate or final values during the calculation of the correction value for a current video line, one intermediate or final value being applicable to a video line of a first field and the other intermediate or final value being applicable to the corresponding video line of a second field of the video frame;selecting in each case that intermediate or final value which is applicable to the current video line of the current field for the purpose of correction;performing a weighted combination of correction step values during the interpolation wherein the intermediate value in each case constitutes at least one weight coefficient for the interpolation calculation;calculating a correction step value for a respective interpolation interval by linear interpolation within said interpolation interval; andcalculating the correction values in a current interval based upon said correction step values for said current interpolation interval and for interpolation intervals before and after said current interpolation interval.