I was curious if you resolved this issue? Some care has been taken with JAI-EXT operations to better handle no data etc... can you confirm your system is setup to use these operations? JAI itself has some ideas for extending the border area to prevent artifacts near edges ideally a solution would hook into this. -- Jody Garnett
On Mon, 16 Mar 2020 at 21:13, Andrew Miskelly <amiske...@weatherzone.com.au> wrote: > Hi GeoTools people, > > I have a pipeline for data from geostationary satellites which involves > the following: > > - use GDAL to reproject the data from its native, geostationary > projection to a cylindrical projection > - use GDAL to arrange the data into a cloud optimised GeoTIFF > - use a GeoTools based server to render imagery from the COG to clients > > The reason for reprojecting is that I've never been able to get GeoTools > to transform from the geostationary projections. > > A basic geographic projection is fine in cases where the satellite is > centred nearer to 0°E but when its field of view encompasses the dateline > it's helpful to use an equidistant cylindrical projection that's centred on > the same longitude as the satellite. That avoids dealing with an image > which spans from 180°W to 180°E and comprises mostly "nodata" pixels (with > the data at the left and right edges). > > When rendering the latter images using GeoTools, though, I get a band of > missing data near the dateline. I'm wondering whether anybody can see where > I'm going wrong. > > To reproduce: > > The following is an image produced from Himawari-8's visible red band, in > the native geostationary projection. > https://anero.id/geotools-202003/himawari-8-visible.tif > > Here it is after reprojecting to +proj=eqc +lon_0=140.7 +ellps=WGS84 > using GDAL. > https://anero.id/geotools-202003/himawari-8-visible-eqc.tif > > And here's the image from GeoTools, rendered using the code below. Note > the band of missing data between about 140°E (the central meridian of the > projection?) and the 180°E (the right hand side of the image). > https://anero.id/geotools-202003/geotools-web-mercator.png > > public void test(File in /* himawari-8-visible-eqc.tif */, File out > /* geotools-web-mercator.png */) { > AbstractGridFormat format = GridFormatFinder.findFormat(in); > AbstractGridCoverage2DReader reader = format.getReader(in); > > Layer rasterLayer = new GridReaderLayer(reader, > > SLD.wrapSymbolizers(CommonFactoryFinder.getStyleFactory().getDefaultRasterSymbolizer())); > > MapContent mapContent = new MapContent(); > mapContent.addLayer(rasterLayer); > > StreamingRenderer renderer = new StreamingRenderer(); > //Map<Object, Object> rendererParams = new HashMap<>(); > //rendererParams.put(StreamingRenderer.CONTINUOUS_MAP_WRAPPING, > Boolean.TRUE); > //renderer.setRendererHints(rendererParams); // had no effect > renderer.setMapContent(mapContent); > > BufferedImage image = new BufferedImage(2048, 2048, > BufferedImage.TYPE_INT_RGB); > try { > renderer.paint(image.createGraphics(), > new Rectangle(image.getWidth(), image.getHeight()), > new ReferencedEnvelope( > -20026376.39, 20026376.39, -20026376.39, > 20026376.39, CRS.decode("EPSG:3857"))); > > ImageIO.write(image, "png", out); > } catch (Exception e) { > e.printStackTrace(); > } > } > > Many thanks in advance for any help. > > Regards, > > Andrew > > _______________________________________________ > GeoTools-GT2-Users mailing list > GeoTools-GT2-Users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/geotools-gt2-users >
_______________________________________________ GeoTools-GT2-Users mailing list GeoTools-GT2-Users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/geotools-gt2-users
