Deblocking of video sequences with lapped embedded IDCT

At mid to low bit-rates, the standard DCT based video codecs produce, in the reconstructed sequences, annoying artifacts known as ringing and blocking effects. We are concerned in blocking artifact removal with lapped embedded IDCT. In intra frames, the deblocking always produces an increase in the peak signal-to-noise ratio; as a consequence of the processing on the last reference intra frame, inter frames, whose prediction error is decoded with IDCT, are free of blocking artifacts. Using the proposed algorithm on the inter frame decreases the resulting PSNR while improving the visual quality of the decoded images. We present a theoretical bound to the PSNR reduction.