6.19 Image Serving

Serving of image and raster data to clients or applications is supported through many features of the GeoRaster PL/SQL and Java APIs.

Direct image serving includes:

• Searching and then subsetting or cropping the rasters (SDO_GEOR.getRasterSubset)
• Applying reprojection and rectification on-the-fly while cropping the images (SDO_GEOR.reproject and SDO_GEOR.rectify).

Virtual mosaic is used mainly, and effectively, to serve an image database to various applications, particularly when you do not want to create large physical mosaics. Virtual mosaic does not require the source images to be preprocessed or mosaicked beforehand. Instead, all images are stored as is, and the whole image data set can be served based on small areas of interest using single calls (SDO_GEOR_AGGR.getMosaicSubset) to the server.

Often, one or a series of preprocessing operations are applied to multiple GeoRaster objects to create the resulting GeoRaster object, and then the features described in this section are used on the resulting GeoRaster object to serve the raster data directly to applications. Thus, a rich set of GeoRaster image manipulation and raster algebra capabilities (described in GeoRaster Data Query and Manipulation, Raster Algebra and Analytics, and this chapter) can be incorporated into the workflow to meet complex image serving requirements.