Mosaic Plugin
-------------

This format make use of a shapefile to act as a kind of index, the features in this shapefile list the filename of the "images" to display and the location in which they should be displayed.

The best source of documentation is (surprise surprise) the code; here are a couple of javadoc links:

* ImageMosaicFormat
* ImageMosaicReader

Related

* :doc:`pyramid`.
* http://docs.geoserver.org/stable/en/user/tutorials/image_mosaic_plugin/imagemosaic.html

An example data set looks something like::
  
  bluemarble.shp
  bluemarble.prj
  bluemarble.properties
  ... a bunch of raster files ...

* Shapefile file
  
  The schema of your shapefile is important:
  
  You MUST have a attribute called "location", this will be used to look up the raster files

* PRJ file
  
  The usual projection file associated with a shapefile, using the WKT format for a
  CoordianteReferenceSystem.
  
* Properties File
  
  The property file is REQUIRED and use to provide a bunch of settings:
  
  Example bluemarble.properties::
    
    #
    #Thu Jan 11 14:53:30 CET 2007
    Name=modis
    ExpandToRGB=true
    Levels=10000.0,10000.0
    LevelsNum=1
    Envelope2D=-3637013.0,-1158091.0 1019969.0,4092819.0
    NumFiles=3
  
  Where the following are required:
  
  * Name
  * ExpandToRGB: true if we need to expand the color model from indexed to rgba
    
    * If all your images use the same indexed palette you can set this to false
      and get a large performance gain
  
  * Levels: list of resolutions
    
    * Format: level_0_x_resolution, level_0_y_resolution, level_1_x_resolution,
      level_1_y_resolution
    * This measure of resolution describes how big each pixel is in real world units
    * Sample calculation: envelope.getLength(0) / image.getWidth()
    * You can define several levels in order to capture overview files if you have them
    
  * LevelsNum: the number of levels mentioned above
  * Envelope2D: bounds in the CRS specified in the prj file
    
    * Format: "minX,minY maxX,maxY"
    
  * NumFiles: should be the same as the number of features in your shapefile