Create GeoTiFF using geotools Java

Question

I have 4000+ raw .tif images. For each image, I have the four corner coordinates in Irish Grid System. I'd like to know how I can use GeoTools to georeference each .tif image using the coordinate values I have.

After following some search, I noted that GeoTools have functionalities for my specific need. But I'm still unable to find a concrete example.

Answer 1

You need a GridCoverageFactory, some data and a bounding box to make what GeoTools calls a coverage. Once you have a coverage writing it out as a GeoTiff is easy.

GridCoverageFactory gcf = new GridCoverageFactory();
CoordinateReferenceSystem crs = CRS.decode("EPSG:27700");
int llx = 500000;
int lly = 105000;
int urx = 501000;
int ury = 106000;
ReferencedEnvelope referencedEnvelope = new ReferencedEnvelope(llx, urx, lly, ury, crs);
GridCoverage2D gc = gcf.create("name", data, referencedEnvelope);
String url = "random.tif";
File file = new File(url);
GeoTiffWriter writer = new GeoTiffWriter(file);
writer.write(gc, null);
writer.dispose();

In the above code data could be a 2 dimensional array of values or a RenderedImage or a WritableRaster. Which you use depends on how you want to read in your tiffs.

I've used EPSG:27700 (OSGB) as my reference system but you would need to use the correct EPSG code for the Irish Grid (probably EPSG:29901). Also I hardcoded the corners but you would need to read those in too.

• 0xMinCha: Thanks @Ian. I'll try the suggested method.
• 0xMinCha: so basically, rendered image is my TiFF image I suppose?
• Ian Turton: yes, depending of course on how you read it in
• 0xMinCha: thanks, may I know what is exactly meant by "how you read it". apologies, it's my first few attempts with Tiffs and Geotools. thanks!