JVET-C0040 Adaptive Clipping in JEM2.0 [F. Galpin, P. Bordes, F. Le Léannec (Technicolor)]

In this contribution, a clipping process within the JEM2.0 coding and decoding process is proposed.

The clipping bounds are determined from the original signal characteristics and encoded in the bitstream.

BD-rate savings of 0.35% is reported in Random Access Configuration, 0.17% in All-Intra and 0.23% in low-delay B. No encoding or decoding runtime increase is reported compared to the JEM2.0 anchor.

Adaptive clipping is performed in all stages where currently clipping to the normal range happens (including the prediction).

During the discussion, it was pointed out that similar methods had been proposed in HEVC standardization (e.g. JCTVC-C146, JCTVC-D123). Gains reported at that time were in a similar range (0.4–0.6%).

Adaptive clipping at various stages is slightly more complex than fixed clipping.

Investigation in an EE was planned , where additionally the following investigations should be performed:

• Clipping only as post processing, not in the loop (which could be indicated by an SEI message)
• Investigate possible impact on visual quality