A method of transforming output formats of video data without degrading display quality. Video data include a plurality of first display data corresponding to a plurality of first odd fields and a plurality of second display data corresponding to a plurality of first even fields. The first display data and the second display data are interlaced to form a plurality of first frames corresponding to a first resolution. The method includes deinterlacing the first and second display data to generate a plurality of third display data, adjusting the third display data for making the third display data correspond to a second resolution, and extracting a plurality of fourth display data corresponding to a plurality of second odd fields and a plurality of fifth display data corresponding to a plurality of second even fields from the third display data.