====== Contour Extraction ======

The raster processing extension comes with a contour extraction utility that's both powerful and fast.

A contour is a line that connects places with the same sample value.  This utility finds contours in raster images.  Contours can be generated on any image that can be opened by Orbit GIS.

{{rap_contourextractor.png|The contour extraction window.}}

^ Image | The image and band to operate on. This must be an opened dataset. |
^ Reference | The reference value to start making contours from. |
^ Include Reference Value | Treat a sample that equals the reference sample value as inside the contour? |
^ Interval | The interval between contours. |
^ Interpolation | The interpolation technique to utilize.  See below for more information.  |
^ Progress | Progress indicator of the generator task. |

===== Interpolation Modes =====

Three interpolation modes are available.

=== No interpolation ===



{{rap_contourextractor_nointerpol.png|No interpolation}}

=== Interpolate edge centers ===

{{rap_contourextractor_centers.png|Interpolate edge centers}}

=== Interpolate edge centers and joints ===

{{rap_contourextractor_centersandjoints.png|Interpolate edge centers and edge joints}}