[Sls-mhdc] Entropy Coder Bit Rates (MHDC-A-1604-7)

[Kiely, Aaron B (332B)]

Dear Working Group,

Here’s an update on entropy coder bit rate results for CCSDS-123.1-B proposals.

First, some of the zipped files of images of mapped quantizer indices were corrupted and could not be unzipped, and a couple of the image files had the wrong file names. My thanks to Enrico for spotting this issue, and my apologies to everyone for these mistakes. Because of the error, there are some omissions in the ESA reported results for a few images at a few values of max_err. I have uploaded corrected versions of the zipped folders that had problems. I believe that all of the zipped data are good now.

A couple of the range coding bit rates in the spreadsheet were incorrect. This has been fixed, and Lucana has uploaded an updated version of the spreadsheet with the corrections (the updated version has “_v2” in the filename).

I have uploaded an additional spreadsheet that repeats the submitted results (but in a different arrangement), but more significantly, includes some additional results. Most notably, results are included for the existing sample-adaptive (GPO2) and block-adaptive (Rice) entropy coders already standardized under CCSDS-123.0-B-1. The spreadsheet is here:
	CWE Private/123.1-B/Entropy Coders Comparison/EntropyCoders_more_data.xls

And finally, I have done some analysis of the different entropy coders and performance results and produced some summary slides which I have uploaded here:
	CWE Private/123.1-B/Entropy Coders Comparison/EntropyCoding_Analysis_Kiely2016-08-25.pdf
I welcome any feedback.

Action item MHDC-A-1604-7(e) calls for us to discuss whether the bit rate results provide enough information for us to make an entropy coder selection. My opinion is that the bit rates reported all represent acceptable performance for a new entropy coding standard, and I’d like to learn more about complexity before attempting to select an entropy coder.

Regards,
Aaron