Panic over. I have just proven that an idiot can panic and cast suspicion on everyone but himself! <br><br>The tiles seem to be reprojected OK, but Geoserver was laying the tiles on top of each other without using any transparency, hence each tile leaving a white blob on top of the last one.<br>
<br>A quick modification to the Input Transparent Color setting and Bob is your fathers brother!<br><br>Thanks again<br><br>Rob<br><br><br><div class="gmail_quote">On 8 June 2010 17:34, <span dir="ltr"><<a href="mailto:christian.mueller@nvoe.at">christian.mueller@nvoe.at</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin: 0pt 0pt 0pt 0.8ex; border-left: 1px solid rgb(204, 204, 204); padding-left: 1ex;">I am not sure here, but this looks like each tile is projected for itself.<br>
<br>
My procedure always is<br>
<br>
1) Build a large image without tiles<br>
2) Reproject<br>
3) Create Tiles/pyramids<br>
<br>
Try to avoid TILED=YES and reproject within the same gdalwarp call.<div><div></div><div class="h5"><br>
<br>
<br>
Quoting Rob <<a href="mailto:gis@vanbooth.com" target="_blank">gis@vanbooth.com</a>>:<br>
<br>
<blockquote class="gmail_quote" style="margin: 0pt 0pt 0pt 0.8ex; border-left: 1px solid rgb(204, 204, 204); padding-left: 1ex;">
Hi<br>
<br>
[Apols for the X-post]<br>
<br>
I'm trying to reproject a set of rasters in order to improve performance on<br>
my application.<br>
<br>
I have a set of rasters in OSGB (EPSG:27700) that I want to pre-process so<br>
that they are in WGS84 (EPSG:4326) within GeoServer, rather than relying on<br>
GeoServer to do the reprojection on the fly.<br>
<br>
I have been reprojecting the rasters using the following command<br>
<br>
<br>
gdalwarp -of GTiff -s_srs "EPSG:27700" -t_srs "EPSG:4326" -co "TILED=YES"<br>
-co "COMPRESS=LZW" -co "TFW=YES" OLDNAME.TIF NEWNAME.TIF<br>
<br>
<br>
I have used the ImageMosaic datastore to load these into GeoServer and can<br>
view them. So far, so good.<br>
<br>
However, there seems to be large gaps between the 'tiles' so that roads no<br>
longer join up and forests have big white gaps within them.<br>
<br>
<blockquote class="gmail_quote" style="margin: 0pt 0pt 0pt 0.8ex; border-left: 1px solid rgb(204, 204, 204); padding-left: 1ex;">
>From checking the rasters and the resultant world files, I've noticed a few<br>
</blockquote>
things.<br>
<br>
1) The image sizes are not constant. All of my original tiles are the same<br>
size. It has raised an interesting question of whether the meridian line<br>
runs parallel to an OSGB Y-axis.<br>
2) The worldfiles also contain some curious values. I understand that the<br>
1st and 4th parameters in a worldfile are the real world distance of a<br>
single pixel, but they seem to have the same value in despite the fact that<br>
the image size changes from being square to being rectangular.<br>
<br>
Whether those things mean anything, or are perfectly legitimate when<br>
reprojecting, I don't know, I just thought I should mention them.<br>
<br>
Has anybody got any advice on how to reproject a full set of rasters, or<br>
what I have done wrong?<br>
<br>
Thanks<br>
<br>
Rob<br>
<br>
</blockquote>
<br>
<br>
<br></div></div>
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