Deep Zoom collections explained Part 2 - the storage and network optimization, dynamic collections

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Fri, 20 Mar 2009 21:20:33 GMT

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re: Deep Zoom collections explained Part 2 - the storage and network optimization, dynamic collections

Daniel Gasienica — Sat, 21 Mar 2009 02:26:43 GMT

Lutz,

Great write-up! The Deep Zoom collection mechanism you describe gave me a huge «a-ha» moment a couple of months back when I first grasped it.

You discussed dynamically adding images to the collection which makes sense the way you describe it. However, what about removing images? Would you just drop the Morton Number and leave the tiles intact? From my understanding this would create a sparse collection with unassigned slots which seems perfectly reasonable for a few removals. Nonetheless, is there something else to consider when removing items from a collection? Do you ever collapse the collection to make it dense in terms of the Morton order?

The last couple of posts were fantastic.

Keep up the good work!

Cheers,

Daniel

re: Deep Zoom collections explained Part 2 - the storage and network optimization, dynamic collections

Lutz — Mon, 23 Mar 2009 23:28:47 GMT

Well the way we handle removing things is to mark them as "removed" in the metadata. That's why there's the nextItemID. I am not sure that is implemented properly in SL2 though, since we didn't test it. But at least it's there in the file format so we can fix bugs if people want to use it without changing the file format.