[Geomoose-users] Estimating tile size

[Paul Wickman]

Thank you kindly, Bob.  Did you use gdal2tiles.py or is there another
utility you like better?


On Tue, Jan 29, 2013 at 1:08 PM, Basques, Bob (CI-StPaul) <
bob.basques at ci.stpaul.mn.us> wrote:

>  Paul,****
>
> ** **
>
> For reference, I’m looking at a layer here for the City, about 56sq mi
> coverage at 6in pxels.  Using Jpeg tiles, 1000x1000pxels (500x500 ground
> units).****
>
> ** **
>
> Keep in mind that the City is not a rectangle . . . but the levels break
> down like so:****
>
> ** **
>
> (L0) ~27,000 tiles = 1.5 GB****
>
> (L1) ~ 4500 tiles = 420MB****
>
> (L2) ~ 1140 Tiles = 123MB****
>
> (L3) ~ 293 tiles = 35MB****
>
> (L4) ~ 83 tiles = 9.4MB****
>
> (L5) ~ 28 tiles = 2.5MB****
>
> ** **
>
> These were generated from MRSID files originally, so I can’t give you a
> number on disksize, since MRSIDs are basically compiled Pyramids to begin
> with.  I have some other layers that started as flat rasters such as your
> TIFFs if you want me to put something together for those, let me know.****
>
> ** **
>
> Bobb****
>
> ** **
>
> ** **
>
> ** **
>
> *From:* geomoose-users-bounces at lists.osgeo.org [mailto:
> geomoose-users-bounces at lists.osgeo.org] *On Behalf Of *Paul Wickman
> *Sent:* Tuesday, January 29, 2013 11:28 AM
> *To:* Brent Fraser
> *Cc:* geomoose-users at lists.osgeo.org
> *Subject:* Re: [Geomoose-users] Estimating tile size****
>
> ** **
>
> Yes, bytes.  Zowie...   I have a TIFF of an air photo for one of our other
> municipalities (also 6-inch resolution), which is 20 GB (uncompress).  That
> coverage is only ~40 square miles.  So, for a single ~800 square mile
> county also at 6-inch resolution I'd potentially be looking at 400 GB for
> the uncompressed source or...  somewhere on the order of ~800 GB tiled?
>  Does that sound right?****
>
> ** **
>
> Anybody from MnGeo on this list with any input?****
>
> ** **
>
> On Tue, Jan 29, 2013 at 11:15 AM, Brent Fraser <bfraser at geoanalytic.com>
> wrote:****
>
> Do you mean how many bytes?
>
> Looking at my Landsat tile pyramids (levels 4 to 12), they're about the
> same number of bytes (hmm, I expected them to be double...)
>
> But my source images:
>     - no compression on existing files (tiffs, e.g not jpeg)
>     - 3 band (color) imagery
>
> The resulting tiles:
>     - compressed PNGs
>     - four bands (one alpha channel for transparency)
>
> So  my guess is somewhere between "same size" to "double the number of
> bytes" (unless the source imagery is compressed, then it will be 5 to 10
> times larger)
>
>
> ****
>
> Best Regards,****
>
> Brent Fraser****
>
>  On 1/28/2013 5:53 PM, Paul Wickman wrote:****
>
>   Greetings, ****
>
> ** **
>
> I know this type of question goes around often in various flavors.
>  Difficult to estimate exact size of rendered tiles, but thought I'd try to
> get some opinions.****
>
> ** **
>
> I see this questions asked in a variety of ways and I know it's not
> exactly precise on how to get the answer, but I'll throw my question out to
> see what I get ;)****
>
> ** **
>
> We have a client who would like us to tile and serve up high-resolution
> aerial photography that they own. The area is about 800 square miles and
> the imagery is 6-inch resolution. They'd like to be able to view the
> imagery at zoom levels 11 through 20 (with level 20 being 1 pixel=6
> inches). Is there any way at all to determine how large a resulting raster
> tile set might be?****
>
> ** **
>
> Many thanks,****
>
>   Paul****
>
> ** **
>
> --
> Paul Wickman
> CTO | Flat Rock Geographics
> 612.280.5850 | paul at flatrockgeo.com
> www.flatrockgeo.com | twitter.com/flatrockgeo ****
>
> ** **
>
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>  ** **
>
>
>
> ****
>
> ** **
>
> --
> Paul Wickman
> CTO | Flat Rock Geographics
> 612.280.5850 | paul at flatrockgeo.com
> www.flatrockgeo.com | twitter.com/flatrockgeo ****
>



-- 
Paul Wickman
CTO | Flat Rock Geographics
612.280.5850 | paul at flatrockgeo.com
www.flatrockgeo.com | twitter.com/flatrockgeo
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