[NTG-context] compresslevel and png graphics (mkiv)

Hi, I just made a one pager (TEXpage) out of a big png graphic (5900x4094). The compressed size of the graphics is normally around 1.37MB on the highest png compress level (9) and 1.32MB after using optipng (only around 3% reduction this time). To my surprise the size of the final PDF was about 2.3MB. After adding '\pdfcompresslevel9' the size went down to 1.48MB. Still not what I wanted... So I was wondering: is there an option to embed the png graphic as it is (no re-compression)? Otherwise the time consuming usage of optipng would be a complete waste of time. Believe it or not, but size matters :-) MTXrun | current version: 2011.01.26 11:02 This is LuaTeX, Version beta-0.71.0-2011051112 (rev 4257) Greetings, Peter