The IlvRasterProperties Class

Programming with JViews Maps > Introducing the Main Classes > Raster Image Management > The IlvRasterProperties Class

The IlvRasterProperties Class

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 setup 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();

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