[Sls-mhdc] CCSDS-123.1-B: "fast neighbor" mode (MHDC-A-1705-6)

[Kiely, Aaron B (332B)]

Dear Working Group,

I have uploaded to the CWE the following documents related to action item MHDC-A-1705-6:
	CWE Private / 123.1-B / Fast_Neighbor_Mode-JPL.{pdf,xlsx}

Building on the nice work that Enrico has done on this action item, I have implemented the FFN1 and FFN4 methods in software along with the simplified hybrid entropy coder. The excel file tabulates bit rate results for test images.

The PDF document describes (1) a mathematically equivalent formulation of the fast neighbor local sum, and (2) a proposed simplification – specifically, that fast neighbor-oriented local sums require the use of reduced mode, rather than requiring an adjustment to the definition of the West local difference d_W. In addition to being simpler, this approach tends to slightly improve rate-distortion performance.

Regards,
Aaron