====== Legend Processing ======

The classification utilities of Orbit GIS can also be used on Raster images.  Please note that Orbit GIS 4.3 only considers images with one band as raster images.

===== Legend =====

Legend options for Raster images are limited to :
  * Basic Appearance 
  * Classification (of sample values)


==== Basic Appearance ====

The basic appearance tab allows you to modify basic image rendering parameters.

=== Missing Values ===

A raster may contain specific samples that are of no real value but rather indicate the given sample is to be ignored for some reason.

Orbit GIS allows you to configure a sample value that's to be considered "background" or a sample value that's to be considered "missing".  When configured, these values will not be used when Orbit GIS creates a histogram.

{{rap_legend_basicappearance.png|:extensions:rasterprocessing:rap_legend_basicappearance.png}}

==== Classification ====

The "Classification" tab is only enabled when a raster image is selected.  

The only classification that can be made is one that classifies the "SampleValue" attribute to a "Thematic Color" parameter which is then used to render the raster.

{{rap_legend_classification.png|:extensions:rasterprocessing:rap_legend_classification.png}}

=== Classification Auto Fill-In ===

Once mappings have been generated, the "Auto Fill-In" utility can be used to apply a gradient or palette to the mappings table.

{{rap_autofillin.png|:extensions:rasterprocessing:rap_autofillin.png}}