progressive loading false or true is same.

    I have finally done some experiments with the different settings for downloading multiresolution tiles.

    The problem is that you are wasting a lot of bandwidth because the viewer always downloads the lower levels in addition to the one you need.

    If you use 512 tiles in 4 levels you will need the 3rd levels always as level2 stops already at a window of larger than 800x500 pixels using MFOV and fov="90"
    This means that you waste min. 1 mb for each pano which is about 30% of the total download for level 3.

    I can not see any difference at all when using progressive false or true.

    I asked back in 2010 about this
    http://www.krpano.com/forum/wbb/inde…work.#post21920
    Klaus said I could add - download="view" - to all <level> tags

    Well that does not make much difference because you still download the lower levels when you start panning.
    However I can see that now the progressive="true" or false makes a small difference.
    With progressive="false" you now do not download level 1

    What I wonder about this is how the viewer handles this. It must mean that the memory use of the viewer must be much larger as it needs to have also level 1 and 2 in memory even if they are not used.
    This would explain the terrible performance I just found using Android tablets with multiresolution. They are 1280x800 and they will use level 3 initiallly.
    I have made the mistake of believing that my small Android HTC Desire Z, which works perfect even with very large cubesizes, could be used as a minimum performance test device but that was a large mistake.

    Hans

    Hi,

    progressive loading means the ordering of the loading,

    roughly it can be defined as:
    progressive=true - from low resolution to high resolution
    progressive=false - from high resolution to low resolution

    the loaded files itself will be almost the same,

    but if that is waste of bandwidth is a matter of opinion - when panning or zooming-out you can see already see something (the lower resolutions) instead of nothing and waiting for the new higher resolution tiles to become ready,

    also note - it doesn't load the complete level, just the tiles that are in the current view area (except the level download setting is "all" or "auto" and the level size is below 10 megapixel, see: https://krpano.com/docu/xml/#image.level.download)

    about performance - the jpeg decoding seems to be very slow on Android and I think this is real problem here - there a lot of tiles to load and decode and this is the reason for the bad performance on some Android tablets,
    you can also try to use just one big level - the performance should be the almost same like when using several levels...

    best regards,
    Klaus

    Quote from klaus.krpano

    also note - it doesn't load the complete level, just the tiles that are in the current view area (except the level download setting is "all" or "auto" and the level size is below 10 megapixel, see: https://krpano.com/docu/xml/#image.level.download)

    Only if I use the download="view" setting.
    If I just use progressive true or false I get all the tiles of level 1 and 2 at the initial view but level 3 is downloaded as I pan around.

    Regarding the bad Android tablets I believe it is also a bad default browser introduced with Homeycomb.
    When I tested a Galaxy 10.1 first time it was no problems. I believe it still had Android 2.3.3 at that time which is what I have-

    I can see that there are a lot of complaints about the slow browser in 3.1 .

    Hans

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