WCUnion.h

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// # WCUnion.h: Make the union of 2 or more image regions
// # Copyright (C) 1998
// # Associated Universities, Inc. Washington DC, USA.
// #
// # This library is free software; you can redistribute it and/or modify it
// # under the terms of the GNU Library General Public License as published by
// # the Free Software Foundation; either version 2 of the License, or (at your
// # option) any later version.
// #
// # This library is distributed in the hope that it will be useful, but WITHOUT
// # ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
// # FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Library General Public
// # License for more details.
// #
// # You should have received a copy of the GNU Library General Public License
// # along with this library; if not, write to the Free Software Foundation,
// # Inc., 675 Massachusetts Ave, Cambridge, MA 02139, USA.
// #
// # Correspondence concerning AIPS++ should be addressed as follows:
// #        Internet email: casa-feedback@nrao.edu.
// #        Postal address: AIPS++ Project Office
// #                        National Radio Astronomy Observatory
// #                        520 Edgemont Road
// #                        Charlottesville, VA 22903-2475 USA
 
#ifndef IMAGES_WCUNION_H
#define IMAGES_WCUNION_H
 
// # Includes
#include <casacore/casa/aips.h>
#include <casacore/images/Regions/WCCompound.h>
 
namespace casacore {  // # NAMESPACE CASACORE - BEGIN
 
// <summary>
// Make the union of 2 or more image regions.
// </summary>
 
// <use visibility=export>
 
// <reviewed reviewer="" date="" tests="">
// </reviewed>
 
// <prerequisite>
//   <li> <linkto class=WCCompound>WCCompound</linkto>
// </prerequisite>
 
// <synopsis>
// The WCUnion class is a specialization of class
// <linkto class=WCCompound>WCCompound</linkto>.
// It makes it possible to take the union of 2 or more image regions.
// Note that only world coordinate regions can be used in a compound,
// thus an LCSlicer object is not allowed in a union.
// <p>
// The union of regions is the collection of the pixels masked-on
// in any region.
// Note that the bounding box of a union is determined by the outermost
// pixels. It means that if regions are very far apart, the bounding
// box of the union is very large and therefore inefficient.
// <p>
// The regions in a union can have different axes and dimensionalities.
// The axes and dimensionality of a union are determined by the
// collection of all different axes in its regions. Each individual region
// will be auto-extended along the axes not being part of the region.
// E.g. one can define a WCBox with axis RA and another WCBox with
// axis DEC. The union will be 2-dim with axes RA and DEC. The first
// box will be auto-extended to cover the DEC axis, which results
// in a 2-dim box with its DEC axis the length of the image's DEC axis.
// Similarly the second box will be auto-extended to cover the RA axis.
// </synopsis>
 
// <example>
// <srcblock>
// </srcblock>
// </example>
 
// # <todo asof="1997/11/11">
// # <li>
// # </todo>
 
class WCUnion : public WCCompound {
 public:
  // Construct the union of one or more image regions.
  // The image regions have to contain WCRegion objects, otherwise an
  // exception is thrown.
  // <group>
  WCUnion(const ImageRegion& region1, const ImageRegion& region2);
  WCUnion(const ImageRegion* region1, const ImageRegion* region2 = 0,
          const ImageRegion* region3 = 0, const ImageRegion* region4 = 0,
          const ImageRegion* region5 = 0, const ImageRegion* region6 = 0,
          const ImageRegion* region7 = 0, const ImageRegion* region8 = 0,
          const ImageRegion* region9 = 0, const ImageRegion* region10 = 0);
  WCUnion(const Block<const ImageRegion*>& regions);
  // </group>
 
  // Construct from multiple regions given as a Block.
  // When <src>takeOver</src> is True, the destructor will delete the
  // given regions. Otherwise a copy of the regions is made.
  WCUnion(Bool takeOver, const Block<const WCRegion*>& regions);
 
  // Copy constructor (copy semantics).
  WCUnion(const WCUnion& other);
 
  virtual ~WCUnion();
 
  // Assignment (copy semantics).
  WCUnion& operator=(const WCUnion& other);
 
  // Comparison
  virtual Bool operator==(const WCRegion& other) const;
 
  // Make a copy of the derived object.
  virtual WCRegion* cloneRegion() const;
 
  // Get the class name (to store in the record).
  static String className();
 
  // Get the region type.  Returns className()
  virtual String type() const;
 
  // Convert the (derived) object to a record.
  virtual TableRecord toRecord(const String& tableName) const;
 
  // Convert correct object from a record.
  static WCUnion* fromRecord(const TableRecord&, const String& tableName);
 
 protected:
  // Convert to an LCRegion using the given coordinate system and shape.
  // pixelAxesMap(i) gives the pixel axis in cSys of axes <src>i</src>
  // in the axesDesc.
  virtual LCRegion* doToLCRegion(const CoordinateSystem& cSys, const IPosition& shape,
                                 const IPosition& pixelAxesMap, const IPosition& outOrder) const;
};
 
}  // namespace casacore
 
#endif