[Geotools-commits] svn - r36799 - trunk/docs/developer/guide/building/maven

[<svn...@os...>]

Author: aaime
Date: 2011-03-28 07:37:58 -0700 (Mon, 28 Mar 2011)
New Revision: 36799

Modified:
   trunk/docs/developer/guide/building/maven/testing.txt
Log:
Adding info on using perceptual diff

Modified: trunk/docs/developer/guide/building/maven/testing.txt
===================================================================
--- trunk/docs/developer/guide/building/maven/testing.txt	2011-03-28 13:57:44 UTC (rev 36798)
+++ trunk/docs/developer/guide/building/maven/testing.txt	2011-03-28 14:37:58 UTC (rev 36799)
@@ -60,6 +60,19 @@
 
 For more information on the use of these "test fixture" files please see the project contentions section on online tests.
 
+Image tests
+^^^^^^^^^^^
+
+Some tests in raster and rendering handling needs to compare images using a human perception model instead of a raw pixel by pixel comparison. To do this we use `"PerceptualDiff" <http://pdiff.sourceforge.net/>`_, an open source command line tool that can do this kind of comparison.
+
+In order for those tests to run PerceptualDiff needs to be installed in your computer, and added in the PATH of your execution environment (if you are on a Debian based distribution all that is needed to achive that is ''sudo apt-get install perceptualdiff'').
+
+If these tests are failing you can also have the system show you the expected and actual image in a GUI popup, to enable it you'll have to use the following profile::
+   
+   mvn test -P interactive.image
+   
+If PerceptualDiff is not installed the tests will be skipped and a message notifying the lack of PerceptualDiff in the PATH will be printed.
+
 Interactive Tests
 ^^^^^^^^^^^^^^^^^