= How to write an OSSIM plugin =

The basic concept described here applies to a filter type plugin which :
 * Takes an image/raster tile
 * Applies some spatial/spectral operator to it
 * Returns a result tile

The plugin demonstrated here is the CFAR plugin found in ossim_plugins contrib folder.
This plugin was built in the following stages:

 *  Copy the sample code from '''ossim/src/examples/shared/image_filters''' to a folder under ossim_plugins, contrib is a good choice.
 * Edit the Filtering method, '''runUcharTransformation''' in the example method with required algorithm.
 *  The required algorithm is in effect a couple of convolutions, hence the ossim3x3convolution filter was extended to implement this.
 *  Write additional house keeping code:
    * Load and save states for saving the chains from VCE and copy pasting.
    * Property setter-getters to modify the filter on the fly via the Properties dialog.


All plugin code must be registered via a factory class to the Ossim Core. In the contrib folder there is a contrib plugin registry(ossimContrinPluginFactory.cpp) to which smaller plugins can be registered.