Index: trunk/psLib/src/image/psImageExtraction.h
===================================================================
--- trunk/psLib/src/image/psImageExtraction.h	(revision 1897)
+++ trunk/psLib/src/image/psImageExtraction.h	(revision 1918)
@@ -10,6 +10,6 @@
 *  @author Robert DeSonia, MHPCC
 *
-*  @version $Revision: 1.13 $ $Name: not supported by cvs2svn $
-*  @date $Date: 2004-09-25 02:06:12 $
+*  @version $Revision: 1.14 $ $Name: not supported by cvs2svn $
+*  @date $Date: 2004-09-28 02:27:58 $
 *
 *  Copyright 2004 Maui High Performance Computing Center, University of Hawaii
@@ -37,16 +37,25 @@
 /** Create a subimage of the specified area.
  *
- * Uses psLib memory allocation functions to create an image based on a larger
- * one.
+ *  Extracts a subimage starting at (col0,row0) to (col1-1,row1-1).  Note: 
+ *  the column col1 and row row1 are NOT included in the resulting subimage.
+ *  In the event that x1 or y1 are non-positive, they shall be interpreted as
+ *  being relative to the size of the parent image in that dimension.
  *
- * @return psImage* : Pointer to psImage.
+ *  If the entire specified subimage is not contained within the parent 
+ *  image, an error results and the return value will be NULL.
+ *
+ *  The resulting psImage does not create a copy of the underlying image 
+ *  data.  Future changes in the parent may be reflecting in the child
+ *  subimage and vis versa.
+ *
+ *  @return psImage* : Pointer to psImage.
  *
  */
 psImage* psImageSubset(
     psImage* image,                    ///< Parent image.
-    unsigned int numCols,              ///< Subimage width (<= image.nCols - col0).
-    unsigned int numRows,              ///< Subimage height (<= image.nRows - row0).
-    unsigned int col0,                 ///< Subimage col-offset (0 <= col0 < nCol).
-    unsigned int row0                  ///< Subimage row-offset (0 <= row0 < nCol).
+    int col0,                          ///< starting column of subimage
+    int row0,                          ///< starting row of subimage
+    int col1,                          ///< exclusive end column of subimage.
+    int row1                           ///< exclusive end row of subimage
 );