coordinate system - Convert image from one EPSG defined CRS to another

I've got a lot of image files (.png or .jpg) that I want to convert from one EPSG defined CRS system to another, e.g. from EPSG:31255 to EPSG:25833, on a server within a Java app.

For each image I know the coordinates (x,y) of the lower left and upper right corner in that specific CRS system.

What I've found so far:

• QGIS: Is able to do this but I'd have to do it by hand (answer)


• GDAL: Is able to convert images but it uses C++ (which I can't use on the server)


• Proj4js: Can only convert coordinates


• Geotools: I've only found information about converting coordinates or full shapefiles so far.

Can GeoTools convert images too or what other Java/JavaScript library can?

Edit:

I'm currently using version 22.2 of GeoTools. The dependencies in the pom.xml file are:

• junit


• gt-shapefile


• gt-swing


• gt-geotiff


• gt-image (not sure if I need that one)


• gt-epsg-hsql

The imports in the java file are:

• import org.geotools.coverage.grid.GridCoverage2D;


• import org.geotools.coverage.grid.io.AbstractGridCoverage2DReader;


• import org.geotools.coverage.grid.io.AbstractGridFormat;


• import org.geotools.coverage.grid.io.GridFormatFinder;


• import org.geotools.coverage.processing.Operations;


• import org.geotools.gce.geotiff.GeoTiffFormat;


• import org.geotools.gce.geotiff.GeoTiffWriter;


• import org.geotools.referencing.CRS;


• import org.geotools.util.factory.Hints;



• import org.opengis.referencing.crs.CoordinateReferenceSystem;

Answer

If you have a matching .wld and .prj file then the gt-image module can read and write jpeg and png files.

Once you've read the file in to a GridCoverage you can reproject it and write it out with no difficulty:

AbstractGridFormat format = GridFormatFinder.findFormat(input);
Hints hints = null;
if (format instanceof GeoTiffFormat) {
  hints = new Hints(Hints.FORCE_LONGITUDE_FIRST_AXIS_ORDER, Boolean.TRUE);
}


AbstractGridCoverage2DReader reader = format.getReader(input, hints);
GridCoverage2D coverage = reader.read(null);
reader.dispose();
GridCoverage2D coverageTransf = (GridCoverage2D) Operations.DEFAULT.resample(coverage, targetCRS);

GeoTiffFormat outFormat = new GeoTiffFormat();
GridCoverageWriter writer = outFormat.getWriter(destFile, hints);
writer.write(coverageTransf, null);
writer.dispose();

Assuming your input image is in input, your target CRS is in targetCRS and the output file is in destFile.

PS: see my blog post on how to add a .prj file to a lot of world images if they are missing.