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Anyone generating custom tiles larger than 256x256? RRS feed

  • Question

  • Curious if anyone is running "super tiles", and if so what has your experience been?

    Also, how are you generating them? I have a code enhancement request submitted with Safe FME for their web map tiler to generate custom dimension tiles (at a factor of 256), but that is slated for 2014 development.

    We process pseudo-realtime tile layers, and my hope is that I can crank out one 1024x1024 tile faster than I can cut sixteen 256x256 tiles. If I can process super tiles faster, this would yield a faster result, and perhaps be able to drop down with some extra zoom with that time savings due to less IO.

    I'd welcome any comments or suggestions on this theory.

    Thursday, November 15, 2012 3:14 AM

Answers

  • Some time ago I did experiment with creating custom tilelayers based on "non-standard" tile dimensions - 128px x 128px, 512px x 512px, 256px x1024px etc. However, I found that it didn't end up being that useful:-

    • each larger individual tile obviously takes longer to download, making the user wait before they see anything on the map
    • the PNG compression didn't seem obviously better on larger images than on smaller images
    • buffering around the edge of the map meant that more total imagesize was held on the client, increasing the memory footprint

    I also tried smaller tiles, but that means that more total image requests need to be made to fill the map, which can result in network requests being throttled.

    And of course there's the fact that almost all existing tile sources and applications default to 256px x 256px, so if you're going for something else you need to create your own tile renderer/cutter.

    Whether by luck or by design, it seems that 256px x256px is pretty much the optimum size for most applications, although YMMV.


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    Thursday, November 15, 2012 12:00 PM
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