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<body class='hmmessage'><div dir='ltr'>Hi Even,<br><br><div>> From: even.rouault@spatialys.com<br>> To: lucena_ivan@hotmail.com<br>> Subject: Re: [gdal-dev] RFC 15: Band Masks vs #5621<br>> Date: Wed, 20 Aug 2014 20:39:29 +0200<br>> CC: gdal-dev@lists.osgeo.org<br>> <br>> > <br>> > I am trying to help a developer how wants to use VRTs as an intermediary<br>> > between a GeoRaster and a PNG, in order to produce thumbnails. In that<br>> > case, does the VRT needs to describe the mask band so that the PNG's<br>> > driver will received the filtered image, with the zeroes regions masked<br>> > out?<br>> <br>> You need to explicitely declare mask bands in the VRT. See the VRT <br>> documentation for that. But that will just declare the existence of the mask <br>> band, and will not do any processing such as zeroing masked regions.<br><br>You are right. GDAL can copy the mask from one dataset to another, depending on the driver. <br><br>But there is no way to indicate that you want the result of the masking, not in the API, not on command line tools.<br><br>Maybe we should add that to the wish list.<br><br>Regards,<br><br>Ivan<br> <br><br></div> </div></body>
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