Hi, I have been experimenting sometimes with Mapserver by creating a huge polygon which has the area of interest as a hole and making a WMS layer from that. Then I forced that layer to be drawn always on top of other layers. It was not very handy and it is perhaps not possible to do with Geoserver. The mask layer should not behave like normal WMS layers because it must not react on ordering layers or setting the transparency. But as an idea it might be faster to cover what should not be shown than extract the area than can be shown. Some sort of WPS would be needed for creating the dynamic reversed mask polygons.
-Jukka Rahkonen- Andrea Aime wrote: > > On Sun, Jun 5, 2011 at 9:41 PM, Ali Taha <[email protected]> wrote: > > Dear All, > > > > > > > > Is it possible to apply a mask on an image, meaning that, I > need to show > > part of an image which is inside another vector layer (polygon)? > > At the moment there is no out of the box way to do so. > There are things under construction that can do it though: > - the new security subsystem > (http://geoserver.org/display/GEOS/GSIP+57+-+Improving+GeoServ er+authorization+framework) > allows to write a custom security implementation that cuts rasters > on the fly, > we have it working but not released to the public right now (it uses > a lot of API > from the customer that sponsored its development, it's not generic) > - on trunk (what will become 2.2.0 in 6 month to one year time) > the "rendering transformations" feature allow one to chain > a wps process > into the sld, in particular one could chain the gs:crop > process that does > exactly what you want, cookie cut a coverage on a user > provided polygon. > We have a blog post showing different kind of processes, > but the machinery > remains the same > > http://geo-solutions.blogspot.com/2011/01/developers-corner-ha > ve-your-sld.html > > Cheers > Andrea > > -- > ------------------------------------------------------- > Ing. Andrea Aime > GeoSolutions S.A.S. > Tech lead > > Via Poggio alle Viti 1187 > 55054 Massarosa (LU) > Italy > > phone: +39 0584 962313 > fax: +39 0584 962313 > > http://www.geo-solutions.it > http://geo-solutions.blogspot.com/ > http://www.youtube.com/user/GeoSolutionsIT > http://www.linkedin.com/in/andreaaime > http://twitter.com/geowolf > > ------------------------------------------------------- > > -------------------------------------------------------------- > ---------------- > EditLive Enterprise is the world's most technically advanced content > authoring tool. Experience the power of Track Changes, Inline Image > Editing and ensure content is compliant with Accessibility Checking. > http://p.sf.net/sfu/ephox-dev2dev > _______________________________________________ > Geoserver-users mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/geoserver-users > ------------------------------------------------------------------------------ EditLive Enterprise is the world's most technically advanced content authoring tool. Experience the power of Track Changes, Inline Image Editing and ensure content is compliant with Accessibility Checking. http://p.sf.net/sfu/ephox-dev2dev _______________________________________________ Geoserver-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/geoserver-users
