ImageMosaic should support generic world files

Martin Desruisseaux added a comment - 28/Dec/07 12:47 PM This is already implemented by the ImageMosaicReader class in development (org.geotools.image.io.mosaic package). It can't work with totally arbitrary AffineTransforms however. For two given AffineTransforms A1 and A2, the following conditions must hold: * The scale ratio A1.getScaleX() / A2.getScaleX() must be an integer or the reciprocal of an integer. * The shear ratio A1.getShearX() / A2.getShearX() must be identical to the above scale ratio. * Same conditions than above must hold for the Y scale and shear (while the can have a different ratio than X). Those conditions are mathematically necessary in order to translate the different AffineTransforms into ImageReader sourceXSubsampling and sourceYSubsampling parameters. If the AffineTransforms do not meet those conditions, then they would need to be handled at a higher level using JAI (which is not ImageMosaicReader's job) - we would lost the optimization that read the whole mosaic in a single BufferedImage in one shot. Checking the AffineTransforms is not very hard, but not trivial neither (see TileBuilder in org.geotools.image.io.mosaic). Unless the developper is confortable with AffineTransform mathematic or unless a patch is needed soon, I would suggest to rely on org.geotools.image.io.mosaic when it will be ready. Some GeoTools code like streaming renderer has suffered and still suffer from incorrect AffineTransform mathematic...