International organisation for standardisation

5.6.3Discussion and Conclusions

A new MDIS LUT was adopted as suggested in JCTVC-F126, as recorded above.

Investigation on BUDI was discontinued.

For further planning of CE6 – see under section 6.15.

5.7CE7: Additional transforms

5.7.1Summary

5.7.1.1.1.1.1.1.1JCTVC-F027 CE7: Summary report of Core Experiment on additional transforms [R. Cohen, C. Yeo, R. Joshi, F. Fernandes (CE coordinators)] [upload 07-08]

The types of proposed transforms and methods generally fall into one or more of the following categories:

• 
  (1,2,6) Mode-dependent DCT/DST or DCT/KLT, where the horizontal and vertical transform depends upon the Intra prediction mode. 8x8 versions and improvements to the existing 4x4 version are tested.
  
• 
  (3) Mode-dependent secondary 4x4 KLT applied to lowest frequency coefficients of 8x8 and larger transform blocks, used horizontally and/or vertically depending upon mode (KLT derived based on DST correlation model).
  
• 
  (4) Secondary rotational 8x8 transform applied to lowest frequency coefficients of 8x8 and larger transform blocks, rate-distortion optimized selection.
  
• 
  (5) Adaptive selection of 2-D DCT or DST, rate-distortion optimized or coefficient-based selection.
  

The last two cases have increase in encoding time as it is necessary to test different transforms. Results overview: