Oyvind,<div><br></div><div>One easy method is to create a vrt file with an alpha band for the original tiff. You can use this to create a compressed raster file that will be </div><div>transparent at nodata pixels.<br><br>
<font face="'courier new', monospace">gdalbuildvrt -addalpha</font></div><div><br></div><div><a href="http://www.gdal.org/gdalbuildvrt.html">http://www.gdal.org/gdalbuildvrt.html</a><br><br><div class="gmail_quote">
On Tue, Apr 3, 2012 at 5:26 PM, Oyvind Idland <span dir="ltr"><<a href="mailto:oyvind.idland@gmail.com">oyvind.idland@gmail.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
Hello,<br><br><br>I got one problem: I have a bunch of uncompressed TIFF tiles, which I am converting to compressed GeoTiff. I would<br>like to mask away the rgb(0,0,0) values.<br><br>However, when I use NODATA on my VRT dataset, there are JPEG artifacts around the edges when rendering.<br>
<br>Is it possible to generate a transparency mask based on NDATA before compressing, or is there any other/better way of <br>doing this ?<br><br>thanks,<br><br>- oyvind<br>
<br>
<br>_______________________________________________<br>
gdal-dev mailing list<br>
<a href="mailto:gdal-dev@lists.osgeo.org">gdal-dev@lists.osgeo.org</a><br>
<a href="http://lists.osgeo.org/mailman/listinfo/gdal-dev" target="_blank">http://lists.osgeo.org/mailman/listinfo/gdal-dev</a><br></blockquote></div><br><br clear="all"><div><br></div>-- <br>Best regards,<br>Chaitanya kumar CH.<br>
<br>+91-9494447584<br>17.2416N 80.1426E<br>
</div>