[OAM-talk] a dramatically simplified technical proposal

Maurizio maurizio at madmappers.com
Wed Nov 11 01:28:55 MST 2009


Thanks for the outline.

> Image tiles should be 256x256 pixels in 8- or 24-bit compressed PNG format

Being a tile person my main concern is that tile format is being too tightly 
restricted leaving out the vast majority of image tile formats currently in 
use:

Google Earth / WorldWind: geographic 512px jpg
Google Maps / YM / and VE: mercator 256px jpg

In actual fact I think most existing OAM tiles would not qualify under the 
proposed format.

While the variety of tile formats might seem superflous they are there for 
precise reasons.

One of them is that internet access outside the US and Europe is both 
extremely slow and extremely expensive: those of you who were at FOSS4g 2008 
in Cape Town last year have have experienced this first hand. Image quality 
is very poor as png 8bit and 24bit pngs are huge and should only be used for 
no-data areas.

In past posts I had noted that one of OAM main aims was to make image data 
accessible for disaster-relief: in Africa we have lot of that.
Accessibility is the key: my personal opinion is that any tile which can be 
viewed in OpenLayer should be considered as suitable.

As madmappers.com  (an African non profit initiative aimed at GIS data 
accessibility) we are prepare to TILE, HOST and SERVE any African data which 
can be distributed publicly.

In actual fact madmappers could immediately start dishing out, under the OAM 
umbrella, a few hundreds of thousands kmsq of already tiled imagery for 
various African countries. But then that should probably be a separate post.

ciao

Maurizio

----- Original Message ----- 
From: "Schuyler Erle" <schuyler at nocat.net>
To: "talk" <talk at openaerialmap.org>
Sent: Tuesday, November 10, 2009 9:30 PM
Subject: [OAM-talk] a dramatically simplified technical proposal


> Hello, friends. In response to feedback both on and off list, I have
> rewritten the previous draft technical proposal into a much, much
> simpler implementation plan that reduces the initial complexity of the
> storage network, and describes the primary use cases:
>
>  http://wiki.openaerialmap.org/Technical_Proposal
>
> I hope that this new proposal highlights the importance of the layer
> catalog.
>
> I have moved all of the lovely-but-possibly impractical P2P stuff here:
>
>  http://wiki.openaerialmap.org/P2P_Network_Proposal
>
> Please, please, please have a look at the new technical proposal draft
> and send comments to the list (or just edit the wiki page).
>
> I will be attending Random Hacks of Kindness in Mountain View on Friday,
> and I would really like to help coordinate interested developers in
> hashing out the first cut of the catalog server and the cache node
> configuration. Please feel free to contact me if you'll be there and
> interested in getting involved.
>
> Thanks!
>
> SDE
>
>
>
>
> _______________________________________________
> talk mailing list
> talk at openaerialmap.org
> http://openaerialmap.org/mailman/listinfo/talk_openaerialmap.org 




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