Re: [Geotools-gt2-users] Image Transformation form one CRS to an other

[Simone G. <sim...@gm...>]

Ok,
I played with the code you sent me:

1>You are doing a strange thing here. You are creating a BufferedImage
to feed it to a Coverage, then you are reprojecting it, which by the
way creates a new RenderedImage having as a source the original
BufferedImage. Then you try to draw this reproject image onto the
first one. I see that you might want to do some god memory reusing by
reusing the first one but it might be a bit risky to overwrite the
source image. You are basically creating  reprojected image B from
original image A (which btw is BufferedImage, hence it is all in
memory untiled) where B is a tiled PlanarImage using a deferred model
which causes computation only on demand. Then you are drawing image B
back onto A. You like to risk huh? :-)

In some cases this should cause a lot of pains, especially with
operations that needs more than one source tile to compute an output
tile (high order interpolation is involved or convolutions). Anyway
let's try the code...

2>I adapted a bit the code as shown below (copy and paste in an editor
if you see it jaggled):


=09public void test() throws FactoryException, IOException {

=09=09// //
=09=09//
=09=09// Here below you have how to correctly create an envelope for a
=09=09// coverage.
=09=09//
=09=09// //
=09=09// final GeneralEnvelope sourceEnvelope =3D new GeneralEnvelope(
=09=09// new double[] { -180, -90 }, new double[] { 180, 90 });
=09=09// sourceEnvelope.setCoordinateReferenceSystem(CRS.decode("EPSG:4326"=
,
=09=09// true));

=09=09// get a reader for the image
=09=09final WorldImageReader wiReader =3D new WorldImageReader(new File(
=09=09=09=09"D:\\data\\ikonos_rgb\\ikonos_rgb.tif"));
=09=09// get the coverage
=09=09GridCoverage2D coverage =3D (GridCoverage2D) wiReader.read(null);

=09=09// now that we have the input image let's try to mess it up writing o=
nto
=09=09// a new bufferedimage with a strange color model
=09=09final BufferedImage bi =3D new BufferedImage(coverage.getGridGeometry=
()
=09=09=09=09.getGridRange().getLength(0), coverage.getGridGeometry()
=09=09=09=09.getGridRange().getLength(1), BufferedImage.TYPE_INT_BGR);
=09=09((Graphics2D) bi.getGraphics())
=09=09=09=09.drawRenderedImage(coverage.getRenderedImage(), AffineTransform
=09=09=09=09=09=09.getTranslateInstance(0, 0));
=09=09coverage =3D FactoryFinder.getGridCoverageFactory(null).create(
=09=09=09=09"I_need_a_long_vacation", bi, coverage.getEnvelope());

=09=09// resample the created coverage
=09=09coverage =3D (GridCoverage2D) Operations.DEFAULT.resample(coverage,
=09=09=09=09CRS.decode("EPSG:32633"));
=09=09final RenderedImage resampled =3Dcoverage.getRenderedImage();

=09=09// Painting some other BufferedImages PNG or JPEGS on the Canvas of
=09=09// by using
=09=09// the bi.getGraphics().drawImage(Image,..) Method
=09=09((Graphics2D) bi.getGraphics()).drawRenderedImage(resampled,
=09=09=09=09AffineTransform.getTranslateInstance(0, 0));

=09=09// write it down
=09=09ImageIO.write(bi, "tiff", new File("d:\\data\\b.tif"));

=09}

Surprise, surpise it works perfectly for me! This is funny (at least
for me :-) for you I bet is annoying!).
Let's try to ddig a bit more. I need to know: platform, geotools
version, JAI version (do you have native libs installed?).
Could you try to avoid drawing on the source image? I rather create a
sibling one.

Talk to you soon.
Simone.

PS:
Not to soon, the elba island is waiting for me, I won't be back until
tuesday 28th of august!



On 8/23/07, Jody Garnett <jga...@re...> wrote:
> Thanks Martin/Tim I have updated the wiki with this description of resamp=
le:
> - http://docs.codehaus.org/display/GEOTDOC/05+Resample+Operation
>
> I also added this question to the referencing FAQ:
> - http://docs.codehaus.org/display/GEOTDOC/11+Referencing+FAQ
>
> Cheers,
> Jody
>
> Martin Desruisseaux wrote:
> > Tim Englich a =E9crit :
> >
> >>> I am looking for a possibility to transform an georefrenced image to =
an
> >>> other coordinatereferencesystem.
> >>> E.g. from EPSG:4326 to EPSG:32632
> >>> Provide GeoTools such a functionality? Do anyone know a (Java)-librar=
y
> >>> which can do that.
> >>>
> >
> > CoordinateReference sourceCRS =3D CRS.decode("EPSG:4326");
> > CoordinateReference targetCRS =3D CRS.decode("EPSG:32632");
> > RenderedImage image =3D ...
> > Envelope imageEnvelope =3D ...
> > imageEnvelope.setCoordinateReferenceSystem(sourceCRS);
> > GridCoverage2D coverage =3D coverageFactory.create("My coverage", image=
, envelope);
> > coverage =3D Operations.DEFAULT.resample(coverage, targetCRS);
> >
> >
> >       Martin
> >
> > -----------------------------------------------------------------------=
--
> > This SF.net email is sponsored by: Splunk Inc.
> > Still grepping through log files to find problems?  Stop.
> > Now Search log events and configuration files using AJAX and a browser.
> > Download your FREE copy of Splunk now >>  http://get.splunk.com/
> > _______________________________________________
> > Geotools-gt2-users mailing list
> > Geo...@li...
> > https://lists.sourceforge.net/lists/listinfo/geotools-gt2-users
> >
>
>
> -------------------------------------------------------------------------
> This SF.net email is sponsored by: Splunk Inc.
> Still grepping through log files to find problems?  Stop.
> Now Search log events and configuration files using AJAX and a browser.
> Download your FREE copy of Splunk now >>  http://get.splunk.com/
> _______________________________________________
> Geotools-gt2-users mailing list
> Geo...@li...
> https://lists.sourceforge.net/lists/listinfo/geotools-gt2-users
>


--=20
-------------------------------------------------------
Eng. Simone Giannecchini
President /CEO GeoSolutions S.A.S.
Via Carignoni 51
55041  Camaiore (LU)
Italy

phone: +39 0584983027
fax:      +39 0584983027
mob:    +39 333 8128928


http://www.geo-solutions.it

-------------------------------------------------------