Parent Topic: <A href="http://www.pcigeomatics.com/cgi-bin/pcihlp/CLWORKS">CLWORKS</a><hr>
<H3>Class Editing</H3>
The purpose of Class Editing is to modify classification results under a 
specified mask. This function is used for the post-classification editing 
of results from various supervised and unsupervised classification
functions (created by other classification functions or PACE programs).
For example, the user can merge a given list of classes into a new class,
using the mouse to select classes in the classified image.
This differs from the Aggregate function in that Class Editing operations
can be performed under a mask instead of the whole image.<p>
The Class Editing panel contains six areas:
<P>
<UL>
<LI> Current File
<LI> Operations 
<LI> Mask Generation 
<LI> Source Class List 
<LI> Destination Class List 
<LI> Reassign or Merge Classes 
</UL>
The Class Editing panel has three action buttons along the bottom:
<P>
<UL>
<LI> Save Classified Image: This button saves editing changes in the 
classified image channel on the database file.
<LI> Close: This button closes the panel (and associated open panels). 
<LI> Help: This button displays this help information. 
</UL>
<H4>Current File</H4>
This indicates the current file that you are working on. You may change the
working file by selecting the ``File ...'' button.
<P>
<H4>Operations</H4>
<PRE>
 The Operations area contains action buttons for the following panels:
</PRE>
<UL>
<LI> Select Classified Image: Selects the classified image channel to edit. 
This will also set the viewing mode to Classified. 
</UL>
<UL>
<LI> Select Reference Image: Selects three channels for an RGB
reference image to display instead of the classified image. 
This will also set the viewing mode to be Reference.
</UL>
<UL>
<LI> Load Full Resolution Area: Loads a full resolution subset of the reference
or classified image to the main ImageWorks window. 
</UL>
<UL>
<LI> Load Mask From Bitmap: Loads the mask from a database bitmap segment. 
</UL>
<UL>
<LI> Save Mask To Bitmap: Saves the mask to a new or existing database bitmap 
segment. 
</UL>
<H4>Mask Generation</H4>
The Mask Generation area is used to draw the mask under which the class 
editing
operations are performed. Mask drawing is done over a full resolution 
subset of the reference or classified image, loaded by the Load Full
Resolution Area panel.<p>
The Modify Colour button in the Mask Generation area opens the Class Colour
Selection panel, used to select the colour of the mask. The default colour 
is white. A small square to the left of the Modify Colour button shows the 
current colour of the mask.<p>
An option menu selects the mode for showing the mask:
<P>
<UL>
<LI> Opaque: Mask is solid; image underneath mask cannot be seen. 
<LI> Not Showing: Mask is not seen; image underneath is completely visible.
</UL>
Another option menu selects which image is to be displayed during mask 
generation:
<P>
<UL>
<LI> Reference: Show RGB reference image.
<LI> Classified: Show pseudo-coloured classified image.
<LI> Image Off: Do not show either image.
</UL>
Function buttons inside the Mask Generation area are used to 
draw the mask border and fill it:
<P>
<UL>
<LI> Clear Mask: Clears (erases) the whole mask. 
<LI> Trace&amp;Close: Traces the mask border while the mouse button is pressed
down, then closes the traced mask when the mouse button is released. 
<LI> Draw Polygon: Draws line segments each time the mouse button is pressed. 
<LI> Close Polygon: Closes the most recent polygon drawn by Draw Polygon. 
<LI> Fill: Fills the area clicked by the mouse.
<LI> Unfill: Unfills (erases) the area clicked by the mouse. 
</UL>
<H4>Source Classes</H4>
The Source Class List area contains a scrolled list of all classes in the 
classified image. This list is used to select ONE OR MORE source classes
for the editing operation. Multiple selection may be made with either
the Shift or Ctrl key pressed down.
In addition, there are three selection control buttons:
<P>
<UL>
<LI> Select: Selects the class at the display cursor position 
(in addition to any classes already selected). 
<LI> Clear All: Clears all selections from the source class list. 
<LI> Select All: Selects all classes in the source class list. 
</UL>
<H4>Destination Classes</H4>
The Destination Class List area also contains a scrolled list of all
available classes. This list is used to select ONLY ONE destination
class for the editing operation. There is one selection control button:
<P>
<UL>
<LI> Select: Selects the class at the display cursor position. 
</UL>
You may also edit the value, name, colour and description of any of 
the classes in the destination list.
<P>
<H4>Reassign, Merge, or Delete Classes</H4>
The Reassign or Merge Classes area shows the names of currently selected 
source classes (or the string ``All Classes'' if all classes were selected) 
and the destination class. The area contains two action buttons for 
performing the reassign (merge) operation:
<P>
<UL>
<LI> ``Over Loaded Image'': Reassigns the selected source classes to the 
destination class over the loaded image (ignoring the mask). 
<LI> ``Under Mask'': Reassigns the selected source classes to the destination 
class under the mask only. 
</UL>
Changes are made automatically to the output image.
<P>
<hr>
Parent Topic: <A href="http://www.pcigeomatics.com/cgi-bin/pcihlp/CLWORKS">CLWORKS</a><br>
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