Need help with TIF TILE SIZE

[Brent Fraser]

Yar,

  The effect you are seeing may be due to re-projecting the UTM tifs to
geographic (latlong).  This results in having a set of nodata (usually
black) pixels around the perimeter of the new tif file.  One solution is to
use the mosaicking feature of gdalwarp to add in the surrounding UTM images
it fill in the gaps.

Brent Fraser


----- Original Message ----- 
From: "Yar Doroshenko" <numerous at GMAIL.COM>
To: <MAPSERVER-USERS at LISTS.UMN.EDU>
Sent: Wednesday, July 06, 2005 9:08 PM
Subject: [UMN_MAPSERVER-USERS] Need help with TIF TILE SIZE


> Hi Guys,
>
> Would anyone be able to answer this one, I'm posting it second time:
>
> My tileindex works fine, I have 51 tig images, I define my layer as the
> folowing:
>
> layer
> name "aerial"
> tileindex mrsid/img_index
> type raster
> status default
> end
>
> My tif images display just fine, the top left corner seems to be
positioned
> correctly. The problem is that at a certain zoom level, there are spaces
> between my tiles and I would like them to overlap. I know that my tifs are
> fine, when I open them in a viewer I can zoom in deep. Is there any way to
> make tifs larger, or make them overlap at a certain zoom level?
>
> Also, here is what I used before I implemented gdaltindex:
>
> I used mrsiddecode to convert my MrSID images to Tif
>
> mrsiddecode -i input.sid -o output.tif -s 2
>
> This way I got my tif to be around 100Mb instead of 2Gb with
gdal_translate
>
> next I did gdalwarp to convert my coordinates
>
> C:\ITS\GDAL\125\bin>gdalwarp -s_srs "+proj=utm +zone=15 +datum=NAD83" -
> t_srs "+p
> roj=latlong +datum=WGS84" 10_1_1.tif latlong.tif
> :0...10...20...30...40...50...60...70...80...90...100 - done.
>
>
> Could anyone see a potential explanation to my tile problem?
>
> Thank you,
>
>
> Yar