Noise reduction method of video transcoding taking into consideration re-coding efficiency of macroblocks

A method of video transcoding that takes into consideration the re-coding efficiency of macroblocks is proposed. The proposed method generates an efficiency list that describes the re-coding efficiency of macroblocks in descending order. Our method selects the macroblocks with high re-coding efficiency in contrast to conventional methods that decide the quantization parameters of macroblocks without taking re-coding efficiency into consideration. This makes it possible to reduce greater numbers of bits with less re-quantization noise. The experimental results revealed that the method we propose produces transcoding peak signal-to-noise ratio (PSNR) scores that are 0.20-0.35 dB better those of a conventional method for all the sequences we tested.