The IlvRasterProperties class collects
information about the raster image to be tiled and the image to be
displayed. This information comprises:
- The raster bounds (coherent with the coordinate system chosen).
- The pixel density (in most cases, this is the ratio between image size and pixel count in each direction).
- The number of blocks in the raster and the number of pixels in a line and in a column of a block. (usually 1).
- The ordering of the pixels in the lines and columns of a block.
- The size that the destination tiles of the raster should adopt.
- The number of pixels the raster has in both directions.
- The transparent pixel value (if any).
- The
ColorModel
to use with the image.
To create and set up raster properties, you
can write, for example:
IlvAdjustableDelegateColorModel csm=new IlvAdjustableDelegateColorModel(myColorModel); IlvRasterProperties p=new IlvRasterProperties(csm); p.setX(xmin); p.setY(ymax); p.setWidth(xmax-xmin); p.setHeight(ymin-ymax); p.setColumnPixelCount(nbCols); p.setLinePixelCount(nbRows); p.setTransparentColorIndex(noDataValue); p.setHorizontalPixelDensity(p.getWidth() / p.getColumnPixelCount()); p.setVerticalPixelDensity(p.getHeight() / p.getLinePixelCount());
In the example above, the IlvAdjustableDelegateColorModel is needed to
provide brightness, saturation and contrast settings for the user.
If the variables
xmin
/
xmax
and
ymin
/
ymax
are in longitudes, latitudes in radians, and the attached
coordinate system is IlvGeographicCoordinateSystem, the reader
uses the WGS84 transformation to be coherent with these raster
properties.
IlvCoordinateTransformation.CreateTransformation( IlvGeographicCoordinateSystem.KERNEL, IlvGeographicCoordinateSystem.WGS84).getTransform();