3.10 Viewing GeoRaster Objects

To view GeoRaster objects, you have the following options:

• Use the standalone GeoRaster viewer tool (one of the tools described in GeoRaster Tools: Viewer_ Loader_ Exporter).

• Use Oracle Spatial Studio or Oracle Spatial Map Visualization Component (formerly known as MapViewer) and its associated Map Builder utility.

With the GeoRaster viewer tool, you can select a GeoRaster object of a database schema (user), query and display the whole or a subset of a GeoRaster object, zoom in and zoom out, scroll, and perform other basic operations. The pyramid level, cell coordinates, and model coordinates (if the object is georeferenced) are displayed for the point at the mouse pointer location. You can display individual cell values and choose different layers of a multiband or hyperspectral image for RGB full color display. The blocking boundaries can be overlapped on the top of the display. Depending on the data and your requests, the viewer can display the raster data in grayscale, pseudocolor, and 24-bit true color over an intranet or the Internet. Some of the basic GeoRaster metadata is also displayed.

The GeoRaster viewer tool allows you to display a virtual mosaic defined as one or a list of GeoRaster tables or views.

The GeoRaster viewer tool provides a set of image processing operators for enhanced display of the GeoRaster objects, especially for those whose cell depth is greater than 8 or is a floating-point number. It can also display and apply bitmap masks on the GeoRaster objects if they have bitmap masks.

The GeoRaster viewer tool also includes menu commands to call the GeoRaster loader and exporter tools, thus enabling you to use a single tool as an interface to the capabilities of all the GeoRaster tools.

Visualization applications can leverage the default RGBA and default pyramid level specifications in the GeoRaster objects. You can set up different bands in a multiband image as the default Red, Green, Blue, and Alpha channels by calling SDO_GEOR.setDefaultColorLayer or SDO_GEOR.setDefaultRed, SDO_GEOR.setDefaultGreen, SDO_GEOR.setDefaultBlue, and SDO_GEOR.setDefaultAlpha. For large images, you can call SDO_GEOR.setDefaultPyramidLevel to set up the best resolution (pyramid) level of an image for initial display in the applications. For example, for a complete overview of a whole image, it is best to set the top pyramid level as the default pyramid level.