diff --git a/ChangeLog b/ChangeLog
index e01733d..d31268a 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -3,6 +3,7 @@
         * Version 1.3.0 released
         =========================
 
+        Added FITS image conversion operators (#1986)
         If code originates from Git, always compile the Python bindings (#1985)
         Raise exception instead of exiting with return code in Python tests (#1983)
         Enhance precision of GCTAEdisp2D::compute_ebounds_src
diff --git a/NEWS b/NEWS
index 11e185a..ae0e1d3 100644
--- a/NEWS
+++ b/NEWS
@@ -67,7 +67,8 @@ None
 
 6. FITS I/O Interface
 ---------------------
-None
+FITS image type conversion constructors have been added to convert a FITS
+image of any type into a specific storage class (#1986).
 
 
 7. Linear algebra module
diff --git a/include/GFitsImageByte.hpp b/include/GFitsImageByte.hpp
index ffc11a6..1f7b56b 100644
--- a/include/GFitsImageByte.hpp
+++ b/include/GFitsImageByte.hpp
@@ -1,7 +1,7 @@
 /***************************************************************************
  *               GFitsImageByte.hpp - FITS Byte image class                *
  * ----------------------------------------------------------------------- *
- *  copyright (C) 2010-2016 by Juergen Knoedlseder                         *
+ *  copyright (C) 2010-2017 by Juergen Knoedlseder                         *
  * ----------------------------------------------------------------------- *
  *                                                                         *
  *  This program is free software: you can redistribute it and/or modify   *
@@ -46,6 +46,7 @@ public:
     GFitsImageByte(const int& nx, const int& ny, const int& nz, const unsigned char* pixels = NULL);
     GFitsImageByte(const int& nx, const int& ny, const int& nz, const int& nt, const unsigned char* pixels = NULL);
     GFitsImageByte(const std::vector<int>& naxes, const unsigned char* pixels = NULL);
+    GFitsImageByte(const GFitsImage& image);
     GFitsImageByte(const GFitsImageByte& image);
     virtual ~GFitsImageByte(void);
 
diff --git a/include/GFitsImageDouble.hpp b/include/GFitsImageDouble.hpp
index 7908c59..e7aabd9 100644
--- a/include/GFitsImageDouble.hpp
+++ b/include/GFitsImageDouble.hpp
@@ -1,7 +1,7 @@
 /***************************************************************************
  *        GFitsImageDouble.hpp - Double precision FITS image class         *
  * ----------------------------------------------------------------------- *
- *  copyright (C) 2008-2016 by Juergen Knoedlseder                         *
+ *  copyright (C) 2008-2017 by Juergen Knoedlseder                         *
  * ----------------------------------------------------------------------- *
  *                                                                         *
  *  This program is free software: you can redistribute it and/or modify   *
@@ -46,6 +46,7 @@ public:
     GFitsImageDouble(const int& nx, const int& ny, const int& nz, const double* pixels = NULL);
     GFitsImageDouble(const int& nx, const int& ny, const int& nz, const int& nt, const double* pixels = NULL);
     GFitsImageDouble(const std::vector<int>& naxes, const double* pixels = NULL);
+    GFitsImageDouble(const GFitsImage& image);
     GFitsImageDouble(const GFitsImageDouble& image);
     virtual ~GFitsImageDouble(void);
 
diff --git a/include/GFitsImageFloat.hpp b/include/GFitsImageFloat.hpp
index ccc1eec..70fcfc3 100644
--- a/include/GFitsImageFloat.hpp
+++ b/include/GFitsImageFloat.hpp
@@ -1,7 +1,7 @@
 /***************************************************************************
  *         GFitsImageFloat.hpp - Single precision FITS image class         *
  * ----------------------------------------------------------------------- *
- *  copyright (C) 2010-2016 by Juergen Knoedlseder                         *
+ *  copyright (C) 2010-2017 by Juergen Knoedlseder                         *
  * ----------------------------------------------------------------------- *
  *                                                                         *
  *  This program is free software: you can redistribute it and/or modify   *
@@ -46,6 +46,7 @@ public:
     GFitsImageFloat(const int& nx, const int& ny, const int& nz, const float* pixels = NULL);
     GFitsImageFloat(const int& nx, const int& ny, const int& nz, const int& nt, const float* pixels = NULL);
     GFitsImageFloat(const std::vector<int>& naxes, const float* pixels = NULL);
+    GFitsImageFloat(const GFitsImage& image);
     GFitsImageFloat(const GFitsImageFloat& image);
     virtual ~GFitsImageFloat(void);
 
diff --git a/include/GFitsImageLong.hpp b/include/GFitsImageLong.hpp
index 6ca6f45..e40e980 100644
--- a/include/GFitsImageLong.hpp
+++ b/include/GFitsImageLong.hpp
@@ -1,7 +1,7 @@
 /***************************************************************************
  *            GFitsImageLong.hpp - Long integer FITS image class           *
  * ----------------------------------------------------------------------- *
- *  copyright (C) 2010-2016 by Juergen Knoedlseder                         *
+ *  copyright (C) 2010-2017 by Juergen Knoedlseder                         *
  * ----------------------------------------------------------------------- *
  *                                                                         *
  *  This program is free software: you can redistribute it and/or modify   *
@@ -46,6 +46,7 @@ public:
     GFitsImageLong(const int& nx, const int& ny, const int& nz, const long* pixels = NULL);
     GFitsImageLong(const int& nx, const int& ny, const int& nz, const int& nt, const long* pixels = NULL);
     GFitsImageLong(const std::vector<int>& naxes, const long* pixels = NULL);
+    GFitsImageLong(const GFitsImage& image);
     GFitsImageLong(const GFitsImageLong& image);
     virtual ~GFitsImageLong(void);
 
diff --git a/include/GFitsImageLongLong.hpp b/include/GFitsImageLongLong.hpp
index 1666032..e116bfe 100644
--- a/include/GFitsImageLongLong.hpp
+++ b/include/GFitsImageLongLong.hpp
@@ -1,7 +1,7 @@
 /***************************************************************************
  *       GFitsImageLongLong.hpp - Long long integer FITS image class       *
  * ----------------------------------------------------------------------- *
- *  copyright (C) 2010-2016 by Juergen Knoedlseder                         *
+ *  copyright (C) 2010-2017 by Juergen Knoedlseder                         *
  * ----------------------------------------------------------------------- *
  *                                                                         *
  *  This program is free software: you can redistribute it and/or modify   *
@@ -46,6 +46,7 @@ public:
     GFitsImageLongLong(const int& nx, const int& ny, const int& nz, const long long* pixels = NULL);
     GFitsImageLongLong(const int& nx, const int& ny, const int& nz, const int& nt, const long long* pixels = NULL);
     GFitsImageLongLong(const std::vector<int>& naxes, const long long* pixels = NULL);
+    GFitsImageLongLong(const GFitsImage& image);
     GFitsImageLongLong(const GFitsImageLongLong& image);
     virtual ~GFitsImageLongLong(void);
 
diff --git a/include/GFitsImageSByte.hpp b/include/GFitsImageSByte.hpp
index 5890c54..52e59ef 100644
--- a/include/GFitsImageSByte.hpp
+++ b/include/GFitsImageSByte.hpp
@@ -1,7 +1,7 @@
 /***************************************************************************
  *            GFitsImageSByte.hpp - Signed Byte FITS image class           *
  * ----------------------------------------------------------------------- *
- *  copyright (C) 2010-2016 by Juergen Knoedlseder                         *
+ *  copyright (C) 2010-2017 by Juergen Knoedlseder                         *
  * ----------------------------------------------------------------------- *
  *                                                                         *
  *  This program is free software: you can redistribute it and/or modify   *
@@ -46,6 +46,7 @@ public:
     GFitsImageSByte(const int& nx, const int& ny, const int& nz, const char* pixels = NULL);
     GFitsImageSByte(const int& nx, const int& ny, const int& nz, const int& nt, const char* pixels = NULL);
     GFitsImageSByte(const std::vector<int>& naxes, const char* pixels = NULL);
+    GFitsImageSByte(const GFitsImage& image);
     GFitsImageSByte(const GFitsImageSByte& image);
     virtual ~GFitsImageSByte(void);
 
diff --git a/include/GFitsImageShort.hpp b/include/GFitsImageShort.hpp
index 9c0cc1d..c62a8f5 100644
--- a/include/GFitsImageShort.hpp
+++ b/include/GFitsImageShort.hpp
@@ -1,7 +1,7 @@
 /***************************************************************************
  *          GFitsImageShort.hpp - Short integer FITS image class           *
  * ----------------------------------------------------------------------- *
- *  copyright (C) 2010-2016 by Juergen Knoedlseder                         *
+ *  copyright (C) 2010-2017 by Juergen Knoedlseder                         *
  * ----------------------------------------------------------------------- *
  *                                                                         *
  *  This program is free software: you can redistribute it and/or modify   *
@@ -46,6 +46,7 @@ public:
     GFitsImageShort(const int& nx, const int& ny, const int& nz, const short* pixels = NULL);
     GFitsImageShort(const int& nx, const int& ny, const int& nz, const int& nt, const short* pixels = NULL);
     GFitsImageShort(const std::vector<int>& naxes, const short* pixels = NULL);
+    GFitsImageShort(const GFitsImage& image);
     GFitsImageShort(const GFitsImageShort& image);
     virtual ~GFitsImageShort(void);
 
diff --git a/include/GFitsImageULong.hpp b/include/GFitsImageULong.hpp
index 1ba01b4..ae01407 100644
--- a/include/GFitsImageULong.hpp
+++ b/include/GFitsImageULong.hpp
@@ -1,7 +1,7 @@
 /***************************************************************************
  *          GFitsImageULong.hpp - Unsigned long image FITS class           *
  * ----------------------------------------------------------------------- *
- *  copyright (C) 2010-2016 by Juergen Knoedlseder                         *
+ *  copyright (C) 2010-2017 by Juergen Knoedlseder                         *
  * ----------------------------------------------------------------------- *
  *                                                                         *
  *  This program is free software: you can redistribute it and/or modify   *
@@ -46,6 +46,7 @@ public:
     GFitsImageULong(const int& nx, const int& ny, const int& nz, const unsigned long* pixels = NULL);
     GFitsImageULong(const int& nx, const int& ny, const int& nz, const int& nt, const unsigned long* pixels = NULL);
     GFitsImageULong(const std::vector<int>& naxes, const unsigned long* pixels = NULL);
+    GFitsImageULong(const GFitsImage& image);
     GFitsImageULong(const GFitsImageULong& image);
     virtual ~GFitsImageULong(void);
 
diff --git a/include/GFitsImageUShort.hpp b/include/GFitsImageUShort.hpp
index 0dd7d3b..257fa83 100644
--- a/include/GFitsImageUShort.hpp
+++ b/include/GFitsImageUShort.hpp
@@ -1,7 +1,7 @@
 /***************************************************************************
  *         GFitsImageUShort.hpp - Unsigned short FITS image class          *
  * ----------------------------------------------------------------------- *
- *  copyright (C) 2010-2016 by Juergen Knoedlseder                         *
+ *  copyright (C) 2010-2017 by Juergen Knoedlseder                         *
  * ----------------------------------------------------------------------- *
  *                                                                         *
  *  This program is free software: you can redistribute it and/or modify   *
@@ -46,6 +46,7 @@ public:
     GFitsImageUShort(const int& nx, const int& ny, const int& nz, const unsigned short* pixels = NULL);
     GFitsImageUShort(const int& nx, const int& ny, const int& nz, const int& nt, const unsigned short* pixels = NULL);
     GFitsImageUShort(const std::vector<int>& naxes, const unsigned short* pixels = NULL);
+    GFitsImageUShort(const GFitsImage& image);
     GFitsImageUShort(const GFitsImageUShort& image);
     virtual ~GFitsImageUShort(void);
 
diff --git a/pyext/GFitsImageByte.i b/pyext/GFitsImageByte.i
index d61f946..908f556 100644
--- a/pyext/GFitsImageByte.i
+++ b/pyext/GFitsImageByte.i
@@ -1,7 +1,7 @@
 /***************************************************************************
  *                GFitsImageByte.i - FITS Byte image class                 *
  * ----------------------------------------------------------------------- *
- *  copyright (C) 2010-2016 by Juergen Knoedlseder                         *
+ *  copyright (C) 2010-2017 by Juergen Knoedlseder                         *
  * ----------------------------------------------------------------------- *
  *                                                                         *
  *  This program is free software: you can redistribute it and/or modify   *
@@ -44,6 +44,7 @@ public:
     GFitsImageByte(const int& nx, const int& ny, const int& nz, const unsigned char* pixels = NULL);
     GFitsImageByte(const int& nx, const int& ny, const int& nz, const int& nt, const unsigned char* pixels = NULL);
     GFitsImageByte(const std::vector<int>& naxes, const unsigned char* pixels = NULL);
+    GFitsImageByte(const GFitsImage& image);
     GFitsImageByte(const GFitsImageByte& image);
     virtual ~GFitsImageByte(void);
 
diff --git a/pyext/GFitsImageDouble.i b/pyext/GFitsImageDouble.i
index e01bccc..659dd5b 100644
--- a/pyext/GFitsImageDouble.i
+++ b/pyext/GFitsImageDouble.i
@@ -1,7 +1,7 @@
 /***************************************************************************
  *         GFitsImageDouble.i - Double precision FITS image class          *
  * ----------------------------------------------------------------------- *
- *  copyright (C) 2010-2016 by Juergen Knoedlseder                         *
+ *  copyright (C) 2010-2017 by Juergen Knoedlseder                         *
  * ----------------------------------------------------------------------- *
  *                                                                         *
  *  This program is free software: you can redistribute it and/or modify   *
@@ -44,6 +44,7 @@ public:
     GFitsImageDouble(const int& nx, const int& ny, const int& nz, const double* pixels = NULL);
     GFitsImageDouble(const int& nx, const int& ny, const int& nz, const int& nt, const double* pixels = NULL);
     GFitsImageDouble(const std::vector<int>& naxes, const double* pixels = NULL);
+    GFitsImageDouble(const GFitsImage& image);
     GFitsImageDouble(const GFitsImageDouble& image);
     virtual ~GFitsImageDouble(void);
 
diff --git a/pyext/GFitsImageFloat.i b/pyext/GFitsImageFloat.i
index df932d0..a522454 100644
--- a/pyext/GFitsImageFloat.i
+++ b/pyext/GFitsImageFloat.i
@@ -1,7 +1,7 @@
 /***************************************************************************
  *          GFitsImageFloat.i - Single precision FITS image class          *
  * ----------------------------------------------------------------------- *
- *  copyright (C) 2010-2016 by Juergen Knoedlseder                         *
+ *  copyright (C) 2010-2017 by Juergen Knoedlseder                         *
  * ----------------------------------------------------------------------- *
  *                                                                         *
  *  This program is free software: you can redistribute it and/or modify   *
@@ -44,6 +44,7 @@ public:
     GFitsImageFloat(const int& nx, const int& ny, const int& nz, const float* pixels = NULL);
     GFitsImageFloat(const int& nx, const int& ny, const int& nz, const int& nt, const float* pixels = NULL);
     GFitsImageFloat(const std::vector<int>& naxes, const float* pixels = NULL);
+    GFitsImageFloat(const GFitsImage& image);
     GFitsImageFloat(const GFitsImageFloat& image);
     virtual ~GFitsImageFloat(void);
 
diff --git a/pyext/GFitsImageLong.i b/pyext/GFitsImageLong.i
index 334da8b..3c004d6 100644
--- a/pyext/GFitsImageLong.i
+++ b/pyext/GFitsImageLong.i
@@ -1,7 +1,7 @@
 /***************************************************************************
  *             GFitsImageLong.i - Long integer FITS image class            *
  * ----------------------------------------------------------------------- *
- *  copyright (C) 2010-2016 by Juergen Knoedlseder                         *
+ *  copyright (C) 2010-2017 by Juergen Knoedlseder                         *
  * ----------------------------------------------------------------------- *
  *                                                                         *
  *  This program is free software: you can redistribute it and/or modify   *
@@ -44,6 +44,7 @@ public:
     GFitsImageLong(const int& nx, const int& ny, const int& nz, const long* pixels = NULL);
     GFitsImageLong(const int& nx, const int& ny, const int& nz, const int& nt, const long* pixels = NULL);
     GFitsImageLong(const std::vector<int>& naxes, const long* pixels = NULL);
+    GFitsImageLong(const GFitsImage& image);
     GFitsImageLong(const GFitsImageLong& image);
     virtual ~GFitsImageLong(void);
 
diff --git a/pyext/GFitsImageLongLong.i b/pyext/GFitsImageLongLong.i
index 79ae6e8..01ed30d 100644
--- a/pyext/GFitsImageLongLong.i
+++ b/pyext/GFitsImageLongLong.i
@@ -1,7 +1,7 @@
 /***************************************************************************
  *        GFitsImageLongLong.i - Long long integer FITS image class        *
  * ----------------------------------------------------------------------- *
- *  copyright (C) 2010-2016 by Juergen Knoedlseder                         *
+ *  copyright (C) 2010-2017 by Juergen Knoedlseder                         *
  * ----------------------------------------------------------------------- *
  *                                                                         *
  *  This program is free software: you can redistribute it and/or modify   *
@@ -44,6 +44,7 @@ public:
     GFitsImageLongLong(const int& nx, const int& ny, const int& nz, const long long* pixels = NULL);
     GFitsImageLongLong(const int& nx, const int& ny, const int& nz, const int& nt, const long long* pixels = NULL);
     GFitsImageLongLong(const std::vector<int>& naxes, const long long* pixels = NULL);
+    GFitsImageLongLong(const GFitsImage& image);
     GFitsImageLongLong(const GFitsImageLongLong& image);
     virtual ~GFitsImageLongLong(void);
 
diff --git a/pyext/GFitsImageSByte.i b/pyext/GFitsImageSByte.i
index d43004f..01e275d 100644
--- a/pyext/GFitsImageSByte.i
+++ b/pyext/GFitsImageSByte.i
@@ -1,7 +1,7 @@
 /***************************************************************************
  *             GFitsImageSByte.i - Signed Byte FITS image class            *
  * ----------------------------------------------------------------------- *
- *  copyright (C) 2010-2016 by Juergen Knoedlseder                         *
+ *  copyright (C) 2010-2017 by Juergen Knoedlseder                         *
  * ----------------------------------------------------------------------- *
  *                                                                         *
  *  This program is free software: you can redistribute it and/or modify   *
@@ -44,6 +44,7 @@ public:
     GFitsImageSByte(const int& nx, const int& ny, const int& nz, const char* pixels = NULL);
     GFitsImageSByte(const int& nx, const int& ny, const int& nz, const int& nt, const char* pixels = NULL);
     GFitsImageSByte(const std::vector<int>& naxes, const char* pixels = NULL);
+    GFitsImageSByte(const GFitsImage& image);
     GFitsImageSByte(const GFitsImageSByte& image);
     virtual ~GFitsImageSByte(void);
 
diff --git a/pyext/GFitsImageShort.i b/pyext/GFitsImageShort.i
index 169d9cc..eab38da 100644
--- a/pyext/GFitsImageShort.i
+++ b/pyext/GFitsImageShort.i
@@ -1,7 +1,7 @@
 /***************************************************************************
  *           GFitsImageShort.i - Short integer FITS image class            *
  * ----------------------------------------------------------------------- *
- *  copyright (C) 2010-2016 by Juergen Knoedlseder                         *
+ *  copyright (C) 2010-2017 by Juergen Knoedlseder                         *
  * ----------------------------------------------------------------------- *
  *                                                                         *
  *  This program is free software: you can redistribute it and/or modify   *
@@ -44,6 +44,7 @@ public:
     GFitsImageShort(const int& nx, const int& ny, const int& nz, const short* pixels = NULL);
     GFitsImageShort(const int& nx, const int& ny, const int& nz, const int& nt, const short* pixels = NULL);
     GFitsImageShort(const std::vector<int>& naxes, const short* pixels = NULL);
+    GFitsImageShort(const GFitsImage& image);
     GFitsImageShort(const GFitsImageShort& image);
     virtual ~GFitsImageShort(void);
 
diff --git a/pyext/GFitsImageULong.i b/pyext/GFitsImageULong.i
index 6d55cc5..f711a2c 100644
--- a/pyext/GFitsImageULong.i
+++ b/pyext/GFitsImageULong.i
@@ -1,7 +1,7 @@
 /***************************************************************************
  *           GFitsImageULong.i - Unsigned long image FITS class            *
  * ----------------------------------------------------------------------- *
- *  copyright (C) 2010-2016 by Juergen Knoedlseder                         *
+ *  copyright (C) 2010-2017 by Juergen Knoedlseder                         *
  * ----------------------------------------------------------------------- *
  *                                                                         *
  *  This program is free software: you can redistribute it and/or modify   *
@@ -44,6 +44,7 @@ public:
     GFitsImageULong(const int& nx, const int& ny, const int& nz, const unsigned long* pixels = NULL);
     GFitsImageULong(const int& nx, const int& ny, const int& nz, const int& nt, const unsigned long* pixels = NULL);
     GFitsImageULong(const std::vector<int>& naxes, const unsigned long* pixels = NULL);
+    GFitsImageULong(const GFitsImage& image);
     GFitsImageULong(const GFitsImageULong& image);
     virtual ~GFitsImageULong(void);
 
diff --git a/pyext/GFitsImageUShort.i b/pyext/GFitsImageUShort.i
index 36f0027..f9c81b5 100644
--- a/pyext/GFitsImageUShort.i
+++ b/pyext/GFitsImageUShort.i
@@ -1,7 +1,7 @@
 /***************************************************************************
  *          GFitsImageUShort.i - Unsigned short FITS image class           *
  * ----------------------------------------------------------------------- *
- *  copyright (C) 2010-2016 by Juergen Knoedlseder                         *
+ *  copyright (C) 2010-2017 by Juergen Knoedlseder                         *
  * ----------------------------------------------------------------------- *
  *                                                                         *
  *  This program is free software: you can redistribute it and/or modify   *
@@ -45,6 +45,7 @@ public:
     GFitsImageUShort(const int& nx, const int& ny, const int& nz, const unsigned short* pixels = NULL);
     GFitsImageUShort(const int& nx, const int& ny, const int& nz, const int& nt, const unsigned short* pixels = NULL);
     GFitsImageUShort(const std::vector<int>& naxes, const unsigned short* pixels = NULL);
+    GFitsImageUShort(const GFitsImage& image);
     GFitsImageUShort(const GFitsImageUShort& image);
     virtual ~GFitsImageUShort(void);
 
diff --git a/src/fits/GFitsImageByte.cpp b/src/fits/GFitsImageByte.cpp
index 4d0988f..9586b39 100644
--- a/src/fits/GFitsImageByte.cpp
+++ b/src/fits/GFitsImageByte.cpp
@@ -1,7 +1,7 @@
 /***************************************************************************
  *                GFitsImageByte.cpp - FITS Byte image class               *
  * ----------------------------------------------------------------------- *
- *  copyright (C) 2010-2016 by Juergen Knoedlseder                         *
+ *  copyright (C) 2010-2017 by Juergen Knoedlseder                         *
  * ----------------------------------------------------------------------- *
  *                                                                         *
  *  This program is free software: you can redistribute it and/or modify   *
@@ -54,7 +54,7 @@
  ***************************************************************************/
 GFitsImageByte::GFitsImageByte(void) : GFitsImage()
 {
-    // Initialise class members for clean destruction
+    // Initialise class members
     init_members();
 
     // Return
@@ -73,7 +73,7 @@ GFitsImageByte::GFitsImageByte(void) : GFitsImage()
 GFitsImageByte::GFitsImageByte(const int& nx, const unsigned char* pixels) :
                 GFitsImage(G_BITPIX, nx)
 {
-    // Initialise class members for clean destruction
+    // Initialise class members
     init_members();
 
     // Construct data
@@ -97,7 +97,7 @@ GFitsImageByte::GFitsImageByte(const int& nx, const int& ny,
                                const unsigned char* pixels) :
                 GFitsImage(G_BITPIX, nx, ny)
 {
-    // Initialise class members for clean destruction
+    // Initialise class members
     init_members();
 
     // Construct data
@@ -122,7 +122,7 @@ GFitsImageByte::GFitsImageByte(const int& nx, const int& ny, const int& nz,
                                const unsigned char* pixels) :
                 GFitsImage(G_BITPIX, nx, ny, nz)
 {
-    // Initialise class members for clean destruction
+    // Initialise class members
     init_members();
 
     // Construct data
@@ -148,7 +148,7 @@ GFitsImageByte::GFitsImageByte(const int& nx, const int& ny, const int& nz,
                                const int& nt, const unsigned char* pixels) :
                 GFitsImage(G_BITPIX, nx, ny, nz, nt)
 {
-    // Initialise class members for clean destruction
+    // Initialise class members
     init_members();
 
     // Construct data
@@ -173,7 +173,7 @@ GFitsImageByte::GFitsImageByte(const std::vector<int>& naxes,
                                const unsigned char*    pixels) :
                 GFitsImage(G_BITPIX, naxes)
 {
-    // Initialise class members for clean destruction
+    // Initialise class members
     init_members();
 
     // Construct data
@@ -185,6 +185,39 @@ GFitsImageByte::GFitsImageByte(const std::vector<int>& naxes,
 
 
 /***********************************************************************//**
+ * @brief Type conversion constructor
+ *
+ * @param[in] image FITS image.
+ *
+ * This constructor performs the conversion of any image type into a byte
+ * image.
+ ***************************************************************************/
+GFitsImageByte::GFitsImageByte(const GFitsImage& image) :
+                GFitsImage(image)
+{
+    // Initialise class members
+    init_members();
+
+    // Copy pixels
+    if (m_num_pixels > 0) {
+        m_pixels = new unsigned char[m_num_pixels];
+        for (int i = 0; i < m_num_pixels; ++i) {
+            m_pixels[i] = (unsigned char)image.pixel(i);
+        }
+    }
+
+    // Set number of bits per pixel
+    m_bitpix = G_BITPIX;
+
+    // Update header card
+    header()["BITPIX"].value(G_BITPIX);
+
+    // Return
+    return;
+}
+
+
+/***********************************************************************//**
  * @brief Copy constructor
  *
  * @param[in] image FITS image.
@@ -192,7 +225,7 @@ GFitsImageByte::GFitsImageByte(const std::vector<int>& naxes,
 GFitsImageByte::GFitsImageByte(const GFitsImageByte& image) :
                 GFitsImage(image)
 {
-    // Initialise class members for clean destruction
+    // Initialise class members
     init_members();
 
     // Copy members
@@ -239,7 +272,7 @@ GFitsImageByte& GFitsImageByte::operator=(const GFitsImageByte& image)
         // Free members
         free_members();
 
-        // Initialise private members for clean destruction
+        // Initialise private members
         init_members();
 
         // Copy members
diff --git a/src/fits/GFitsImageDouble.cpp b/src/fits/GFitsImageDouble.cpp
index c319a7a..fe62b27 100644
--- a/src/fits/GFitsImageDouble.cpp
+++ b/src/fits/GFitsImageDouble.cpp
@@ -1,7 +1,7 @@
 /***************************************************************************
  *        GFitsImageDouble.cpp - Double precision FITS image class         *
  * ----------------------------------------------------------------------- *
- *  copyright (C) 2008-2016 by Juergen Knoedlseder                         *
+ *  copyright (C) 2008-2017 by Juergen Knoedlseder                         *
  * ----------------------------------------------------------------------- *
  *                                                                         *
  *  This program is free software: you can redistribute it and/or modify   *
@@ -54,7 +54,7 @@
  ***************************************************************************/
 GFitsImageDouble::GFitsImageDouble(void) : GFitsImage()
 {
-    // Initialise class members for clean destruction
+    // Initialise class members
     init_members();
 
     // Return
@@ -73,7 +73,7 @@ GFitsImageDouble::GFitsImageDouble(void) : GFitsImage()
 GFitsImageDouble::GFitsImageDouble(const int& nx, const double* pixels) :
                   GFitsImage(G_BITPIX, nx)
 {
-    // Initialise class members for clean destruction
+    // Initialise class members
     init_members();
 
     // Construct data
@@ -97,7 +97,7 @@ GFitsImageDouble::GFitsImageDouble(const int& nx, const int& ny,
                                    const double* pixels) :
                   GFitsImage(G_BITPIX, nx, ny)
 {
-    // Initialise class members for clean destruction
+    // Initialise class members
     init_members();
 
     // Construct data
@@ -122,7 +122,7 @@ GFitsImageDouble::GFitsImageDouble(const int& nx, const int& ny, const int& nz,
                                    const double* pixels) :
                   GFitsImage(G_BITPIX, nx, ny, nz)
 {
-    // Initialise class members for clean destruction
+    // Initialise class members
     init_members();
 
     // Construct data
@@ -148,7 +148,7 @@ GFitsImageDouble::GFitsImageDouble(const int& nx, const int& ny, const int& nz,
                                    const int& nt, const double* pixels) :
                   GFitsImage(G_BITPIX, nx, ny, nz, nt)
 {
-    // Initialise class members for clean destruction
+    // Initialise class members
     init_members();
 
     // Construct data
@@ -173,7 +173,7 @@ GFitsImageDouble::GFitsImageDouble(const std::vector<int>& naxes,
                                    const double*           pixels) :
                   GFitsImage(G_BITPIX, naxes)
 {
-    // Initialise class members for clean destruction
+    // Initialise class members
     init_members();
 
     // Construct data
@@ -185,6 +185,41 @@ GFitsImageDouble::GFitsImageDouble(const std::vector<int>& naxes,
 
 
 /***********************************************************************//**
+ * @brief Type conversion constructor
+ *
+ * @param[in] image FITS image.
+ *
+ * This constructor performs the conversion of any image type into a double
+ * precision floating point image.
+ ***************************************************************************/
+GFitsImageDouble::GFitsImageDouble(const GFitsImage& image) :
+                  GFitsImage(image)
+{
+    // Initialise class members
+    init_members();
+
+    // Copy pixels
+    if (m_num_pixels > 0) {
+        m_pixels = new double[m_num_pixels];
+        for (int i = 0; i < m_num_pixels; ++i) {
+            m_pixels[i] = (double)image.pixel(i);
+        }
+    }
+
+    // Set number of bits per pixel
+    m_bitpix = G_BITPIX;
+
+    // Update header card
+    header()["BITPIX"].value(G_BITPIX);
+
+    // Return
+    return;
+}
+
+
+
+
+/***********************************************************************//**
  * @brief Copy constructor
  *
  * @param[in] image FITS image.
@@ -192,7 +227,7 @@ GFitsImageDouble::GFitsImageDouble(const std::vector<int>& naxes,
 GFitsImageDouble::GFitsImageDouble(const GFitsImageDouble& image) :
                   GFitsImage(image)
 {
-    // Initialise class members for clean destruction
+    // Initialise class members
     init_members();
 
     // Copy members
@@ -238,7 +273,7 @@ GFitsImageDouble& GFitsImageDouble::operator=(const GFitsImageDouble& image)
         // Free members
         free_members();
 
-        // Initialise private members for clean destruction
+        // Initialise private members
         init_members();
 
         // Copy members
diff --git a/src/fits/GFitsImageFloat.cpp b/src/fits/GFitsImageFloat.cpp
index 220e204..dc93d0d 100644
--- a/src/fits/GFitsImageFloat.cpp
+++ b/src/fits/GFitsImageFloat.cpp
@@ -54,7 +54,7 @@
  ***************************************************************************/
 GFitsImageFloat::GFitsImageFloat(void) : GFitsImage()
 {
-    // Initialise class members for clean destruction
+    // Initialise class members
     init_members();
 
     // Return
@@ -73,7 +73,7 @@ GFitsImageFloat::GFitsImageFloat(void) : GFitsImage()
 GFitsImageFloat::GFitsImageFloat(const int& nx, const float* pixels) :
                  GFitsImage(G_BITPIX, nx)
 {
-    // Initialise class members for clean destruction
+    // Initialise class members
     init_members();
 
     // Construct data
@@ -97,7 +97,7 @@ GFitsImageFloat::GFitsImageFloat(const int& nx, const int& ny,
                                  const float* pixels) :
                  GFitsImage(G_BITPIX, nx, ny)
 {
-    // Initialise class members for clean destruction
+    // Initialise class members
     init_members();
 
     // Construct data
@@ -122,7 +122,7 @@ GFitsImageFloat::GFitsImageFloat(const int& nx, const int& ny, const int& nz,
                                  const float* pixels) :
                  GFitsImage(G_BITPIX, nx, ny, nz)
 {
-    // Initialise class members for clean destruction
+    // Initialise class members
     init_members();
 
     // Construct data
@@ -148,7 +148,7 @@ GFitsImageFloat::GFitsImageFloat(const int& nx, const int& ny, const int& nz,
                                  const int& nt, const float* pixels) :
                  GFitsImage(G_BITPIX, nx, ny, nz, nt)
 {
-    // Initialise class members for clean destruction
+    // Initialise class members
     init_members();
 
     // Construct data from pixels
@@ -173,7 +173,7 @@ GFitsImageFloat::GFitsImageFloat(const std::vector<int>& naxes,
                                  const float*            pixels) :
                  GFitsImage(G_BITPIX, naxes)
 {
-    // Initialise class members for clean destruction
+    // Initialise class members
     init_members();
 
     // Construct data from pixels
@@ -185,6 +185,39 @@ GFitsImageFloat::GFitsImageFloat(const std::vector<int>& naxes,
 
 
 /***********************************************************************//**
+ * @brief Type conversion constructor
+ *
+ * @param[in] image FITS image.
+ *
+ * This constructor performs the conversion of any image type into a single
+ * precision floating point image.
+ ***************************************************************************/
+GFitsImageFloat::GFitsImageFloat(const GFitsImage& image) :
+                 GFitsImage(image)
+{
+    // Initialise class members
+    init_members();
+
+    // Copy pixels
+    if (m_num_pixels > 0) {
+        m_pixels = new float[m_num_pixels];
+        for (int i = 0; i < m_num_pixels; ++i) {
+            m_pixels[i] = (float)image.pixel(i);
+        }
+    }
+
+    // Set number of bits per pixel
+    m_bitpix = G_BITPIX;
+
+    // Update header card
+    header()["BITPIX"].value(G_BITPIX);
+
+    // Return
+    return;
+}
+
+
+/***********************************************************************//**
  * @brief Copy constructor
  *
  * @param[in] image FITS image.
@@ -192,7 +225,7 @@ GFitsImageFloat::GFitsImageFloat(const std::vector<int>& naxes,
 GFitsImageFloat::GFitsImageFloat(const GFitsImageFloat& image) :
                  GFitsImage(image)
 {
-    // Initialise class members for clean destruction
+    // Initialise class members
     init_members();
 
     // Copy members
diff --git a/src/fits/GFitsImageLong.cpp b/src/fits/GFitsImageLong.cpp
index eb2ca78..29af22d 100644
--- a/src/fits/GFitsImageLong.cpp
+++ b/src/fits/GFitsImageLong.cpp
@@ -1,7 +1,7 @@
 /***************************************************************************
  *            GFitsImageLong.cpp - Long integer FITS image class           *
  * ----------------------------------------------------------------------- *
- *  copyright (C) 2010-2016 by Juergen Knoedlseder                         *
+ *  copyright (C) 2010-2017 by Juergen Knoedlseder                         *
  * ----------------------------------------------------------------------- *
  *                                                                         *
  *  This program is free software: you can redistribute it and/or modify   *
@@ -54,7 +54,7 @@
  ***************************************************************************/
 GFitsImageLong::GFitsImageLong(void) : GFitsImage()
 {
-    // Initialise class members for clean destruction
+    // Initialise class members
     init_members();
 
     // Return
@@ -73,7 +73,7 @@ GFitsImageLong::GFitsImageLong(void) : GFitsImage()
 GFitsImageLong::GFitsImageLong(const int& nx, const long* pixels) :
                 GFitsImage(G_BITPIX, nx)
 {
-    // Initialise class members for clean destruction
+    // Initialise class members
     init_members();
 
     // Construct data
@@ -96,7 +96,7 @@ GFitsImageLong::GFitsImageLong(const int& nx, const long* pixels) :
 GFitsImageLong::GFitsImageLong(const int& nx, const int& ny, const long* pixels) :
                 GFitsImage(G_BITPIX, nx, ny)
 {
-    // Initialise class members for clean destruction
+    // Initialise class members
     init_members();
 
     // Construct data
@@ -121,7 +121,7 @@ GFitsImageLong::GFitsImageLong(const int& nx, const int& ny, const int& nz,
                                const long* pixels) :
                 GFitsImage(G_BITPIX, nx, ny, nz)
 {
-    // Initialise class members for clean destruction
+    // Initialise class members
     init_members();
 
     // Construct data
@@ -147,7 +147,7 @@ GFitsImageLong::GFitsImageLong(const int& nx, const int& ny, const int& nz,
                                const int& nt, const long* pixels) :
                 GFitsImage(G_BITPIX, nx, ny, nz, nt)
 {
-    // Initialise class members for clean destruction
+    // Initialise class members
     init_members();
 
     // Construct data
@@ -172,7 +172,7 @@ GFitsImageLong::GFitsImageLong(const std::vector<int>& naxes,
                                const long*             pixels) :
                 GFitsImage(G_BITPIX, naxes)
 {
-    // Initialise class members for clean destruction
+    // Initialise class members
     init_members();
 
     // Construct data
@@ -184,6 +184,39 @@ GFitsImageLong::GFitsImageLong(const std::vector<int>& naxes,
 
 
 /***********************************************************************//**
+ * @brief Type conversion constructor
+ *
+ * @param[in] image FITS image.
+ *
+ * This constructor performs the conversion of any image type into a long
+ * integer image.
+ ***************************************************************************/
+GFitsImageLong::GFitsImageLong(const GFitsImage& image) :
+                GFitsImage(image)
+{
+    // Initialise class members
+    init_members();
+
+    // Copy pixels
+    if (m_num_pixels > 0) {
+        m_pixels = new long[m_num_pixels];
+        for (int i = 0; i < m_num_pixels; ++i) {
+            m_pixels[i] = (long)image.pixel(i);
+        }
+    }
+
+    // Set number of bits per pixel
+    m_bitpix = G_BITPIX;
+
+    // Update header card
+    header()["BITPIX"].value(G_BITPIX);
+
+    // Return
+    return;
+}
+
+
+/***********************************************************************//**
  * @brief Copy constructor
  *
  * @param[in] image FITS image.
@@ -191,7 +224,7 @@ GFitsImageLong::GFitsImageLong(const std::vector<int>& naxes,
 GFitsImageLong::GFitsImageLong(const GFitsImageLong& image) :
                 GFitsImage(image)
 {
-    // Initialise class members for clean destruction
+    // Initialise class members
     init_members();
 
     // Copy members
@@ -237,7 +270,7 @@ GFitsImageLong& GFitsImageLong::operator=(const GFitsImageLong& image)
         // Free members
         free_members();
 
-        // Initialise private members for clean destruction
+        // Initialise private members
         init_members();
 
         // Copy members
diff --git a/src/fits/GFitsImageLongLong.cpp b/src/fits/GFitsImageLongLong.cpp
index 8f2da75..c22427f 100644
--- a/src/fits/GFitsImageLongLong.cpp
+++ b/src/fits/GFitsImageLongLong.cpp
@@ -1,7 +1,7 @@
 /***************************************************************************
  *       GFitsImageLongLong.cpp - Long long integer FITS image class       *
  * ----------------------------------------------------------------------- *
- *  copyright (C) 2010-2016 by Juergen Knoedlseder                         *
+ *  copyright (C) 2010-2017 by Juergen Knoedlseder                         *
  * ----------------------------------------------------------------------- *
  *                                                                         *
  *  This program is free software: you can redistribute it and/or modify   *
@@ -54,7 +54,7 @@
  ***************************************************************************/
 GFitsImageLongLong::GFitsImageLongLong(void) : GFitsImage()
 {
-    // Initialise class members for clean destruction
+    // Initialise class members
     init_members();
 
     // Return
@@ -73,7 +73,7 @@ GFitsImageLongLong::GFitsImageLongLong(void) : GFitsImage()
 GFitsImageLongLong::GFitsImageLongLong(const int& nx, const long long* pixels) :
                     GFitsImage(G_BITPIX, nx)
 {
-    // Initialise class members for clean destruction
+    // Initialise class members
     init_members();
 
     // Construct data
@@ -97,7 +97,7 @@ GFitsImageLongLong::GFitsImageLongLong(const int& nx, const int& ny,
                                        const long long* pixels) :
                     GFitsImage(G_BITPIX, nx, ny)
 {
-    // Initialise class members for clean destruction
+    // Initialise class members
     init_members();
 
     // Construct data
@@ -123,7 +123,7 @@ GFitsImageLongLong::GFitsImageLongLong(const int& nx, const int& ny,
                                        const long long* pixels) :
                     GFitsImage(G_BITPIX, nx, ny, nz)
 {
-    // Initialise class members for clean destruction
+    // Initialise class members
     init_members();
 
     // Construct data
@@ -150,7 +150,7 @@ GFitsImageLongLong::GFitsImageLongLong(const int& nx, const int& ny,
                                        const long long* pixels) :
                     GFitsImage(G_BITPIX, nx, ny, nz, nt)
 {
-    // Initialise class members for clean destruction
+    // Initialise class members
     init_members();
 
     // Construct data
@@ -175,7 +175,7 @@ GFitsImageLongLong::GFitsImageLongLong(const std::vector<int>& naxes,
                                        const long long*        pixels) :
                     GFitsImage(G_BITPIX, naxes)
 {
-    // Initialise class members for clean destruction
+    // Initialise class members
     init_members();
 
     // Construct data
@@ -187,6 +187,39 @@ GFitsImageLongLong::GFitsImageLongLong(const std::vector<int>& naxes,
 
 
 /***********************************************************************//**
+ * @brief Type conversion constructor
+ *
+ * @param[in] image FITS image.
+ *
+ * This constructor performs the conversion of any image type into a long
+ * long integer image.
+ ***************************************************************************/
+GFitsImageLongLong::GFitsImageLongLong(const GFitsImage& image) :
+                    GFitsImage(image)
+{
+    // Initialise class members
+    init_members();
+
+    // Copy pixels
+    if (m_num_pixels > 0) {
+        m_pixels = new long long[m_num_pixels];
+        for (int i = 0; i < m_num_pixels; ++i) {
+            m_pixels[i] = (long long)image.pixel(i);
+        }
+    }
+
+    // Set number of bits per pixel
+    m_bitpix = G_BITPIX;
+
+    // Update header card
+    header()["BITPIX"].value(G_BITPIX);
+
+    // Return
+    return;
+}
+
+
+/***********************************************************************//**
  * @brief Copy constructor
  *
  * @param[in] image FITS image.
@@ -194,7 +227,7 @@ GFitsImageLongLong::GFitsImageLongLong(const std::vector<int>& naxes,
 GFitsImageLongLong::GFitsImageLongLong(const GFitsImageLongLong& image) :
                     GFitsImage(image)
 {
-    // Initialise class members for clean destruction
+    // Initialise class members
     init_members();
 
     // Copy members
@@ -240,7 +273,7 @@ GFitsImageLongLong& GFitsImageLongLong::operator=(const GFitsImageLongLong& imag
         // Free members
         free_members();
 
-        // Initialise private members for clean destruction
+        // Initialise private members
         init_members();
 
         // Copy members
diff --git a/src/fits/GFitsImageSByte.cpp b/src/fits/GFitsImageSByte.cpp
index 982a9df..d4f0c0a 100644
--- a/src/fits/GFitsImageSByte.cpp
+++ b/src/fits/GFitsImageSByte.cpp
@@ -1,7 +1,7 @@
 /***************************************************************************
  *            GFitsImageSByte.cpp - Signed Byte FITS image class           *
  * ----------------------------------------------------------------------- *
- *  copyright (C) 2010-2016 by Juergen Knoedlseder                         *
+ *  copyright (C) 2010-2017 by Juergen Knoedlseder                         *
  * ----------------------------------------------------------------------- *
  *                                                                         *
  *  This program is free software: you can redistribute it and/or modify   *
@@ -54,7 +54,7 @@
  ***************************************************************************/
 GFitsImageSByte::GFitsImageSByte(void) : GFitsImage()
 {
-    // Initialise class members for clean destruction
+    // Initialise class members
     init_members();
 
     // Return
@@ -73,7 +73,7 @@ GFitsImageSByte::GFitsImageSByte(void) : GFitsImage()
 GFitsImageSByte::GFitsImageSByte(const int& nx, const char* pixels) :
                  GFitsImage(G_BITPIX, nx)
 {
-    // Initialise class members for clean destruction
+    // Initialise class members
     init_members();
 
     // Construct data
@@ -97,7 +97,7 @@ GFitsImageSByte::GFitsImageSByte(const int& nx, const int& ny,
                                  const char* pixels) :
                  GFitsImage(G_BITPIX, nx, ny)
 {
-    // Initialise class members for clean destruction
+    // Initialise class members
     init_members();
 
     // Construct data
@@ -122,7 +122,7 @@ GFitsImageSByte::GFitsImageSByte(const int& nx, const int& ny, const int& nz,
                                  const char* pixels) :
                  GFitsImage(G_BITPIX, nx, ny, nz)
 {
-    // Initialise class members for clean destruction
+    // Initialise class members
     init_members();
 
     // Construct data
@@ -149,7 +149,7 @@ GFitsImageSByte::GFitsImageSByte(const int& nx, const int& ny, const int& nz,
                                  const char* pixels) :
                  GFitsImage(G_BITPIX, nx, ny, nz, nt)
 {
-    // Initialise class members for clean destruction
+    // Initialise class members
     init_members();
 
     // Construct data
@@ -174,7 +174,7 @@ GFitsImageSByte::GFitsImageSByte(const std::vector<int>& naxes,
                                  const char*             pixels) :
                  GFitsImage(G_BITPIX, naxes)
 {
-    // Initialise class members for clean destruction
+    // Initialise class members
     init_members();
 
     // Construct data
@@ -186,6 +186,39 @@ GFitsImageSByte::GFitsImageSByte(const std::vector<int>& naxes,
 
 
 /***********************************************************************//**
+ * @brief Type conversion constructor
+ *
+ * @param[in] image FITS image.
+ *
+ * This constructor performs the conversion of any image type into a signed
+ * byte image.
+ ***************************************************************************/
+GFitsImageSByte::GFitsImageSByte(const GFitsImage& image) :
+                 GFitsImage(image)
+{
+    // Initialise class members
+    init_members();
+
+    // Copy pixels
+    if (m_num_pixels > 0) {
+        m_pixels = new char[m_num_pixels];
+        for (int i = 0; i < m_num_pixels; ++i) {
+            m_pixels[i] = (char)image.pixel(i);
+        }
+    }
+
+    // Set number of bits per pixel
+    m_bitpix = G_BITPIX;
+
+    // Update header card
+    header()["BITPIX"].value(G_BITPIX);
+
+    // Return
+    return;
+}
+
+
+/***********************************************************************//**
  * @brief Copy constructor
  *
  * @param[in] image FITS image.
@@ -193,7 +226,7 @@ GFitsImageSByte::GFitsImageSByte(const std::vector<int>& naxes,
 GFitsImageSByte::GFitsImageSByte(const GFitsImageSByte& image) :
                  GFitsImage(image)
 {
-    // Initialise class members for clean destruction
+    // Initialise class members
     init_members();
 
     // Copy members
@@ -239,7 +272,7 @@ GFitsImageSByte& GFitsImageSByte::operator=(const GFitsImageSByte& image)
         // Free members
         free_members();
 
-        // Initialise private members for clean destruction
+        // Initialise private members
         init_members();
 
         // Copy members
diff --git a/src/fits/GFitsImageShort.cpp b/src/fits/GFitsImageShort.cpp
index 275bbf2..e8152c2 100644
--- a/src/fits/GFitsImageShort.cpp
+++ b/src/fits/GFitsImageShort.cpp
@@ -1,7 +1,7 @@
 /***************************************************************************
  *          GFitsImageShort.cpp - Short integer FITS image class           *
  * ----------------------------------------------------------------------- *
- *  copyright (C) 2010-2016 by Juergen Knoedlseder                         *
+ *  copyright (C) 2010-2017 by Juergen Knoedlseder                         *
  * ----------------------------------------------------------------------- *
  *                                                                         *
  *  This program is free software: you can redistribute it and/or modify   *
@@ -54,7 +54,7 @@
  ***************************************************************************/
 GFitsImageShort::GFitsImageShort(void) : GFitsImage()
 {
-    // Initialise class members for clean destruction
+    // Initialise class members
     init_members();
 
     // Return
@@ -73,7 +73,7 @@ GFitsImageShort::GFitsImageShort(void) : GFitsImage()
 GFitsImageShort::GFitsImageShort(const int& nx, const short* pixels) :
                  GFitsImage(G_BITPIX, nx)
 {
-    // Initialise class members for clean destruction
+    // Initialise class members
     init_members();
 
     // Construct data
@@ -97,7 +97,7 @@ GFitsImageShort::GFitsImageShort(const int& nx, const int& ny,
                                  const short* pixels) :
                  GFitsImage(G_BITPIX, nx, ny)
 {
-    // Initialise class members for clean destruction
+    // Initialise class members
     init_members();
 
     // Construct data
@@ -122,7 +122,7 @@ GFitsImageShort::GFitsImageShort(const int& nx, const int& ny, const int& nz,
                                  const short* pixels) :
                  GFitsImage(G_BITPIX, nx, ny, nz)
 {
-    // Initialise class members for clean destruction
+    // Initialise class members
     init_members();
 
     // Construct data
@@ -148,7 +148,7 @@ GFitsImageShort::GFitsImageShort(const int& nx, const int& ny, const int& nz,
                                  const int& nt, const short* pixels) :
                  GFitsImage(G_BITPIX, nx, ny, nz, nt)
 {
-    // Initialise class members for clean destruction
+    // Initialise class members
     init_members();
 
     // Construct data
@@ -173,7 +173,7 @@ GFitsImageShort::GFitsImageShort(const std::vector<int>& naxes,
                                  const short*            pixels) :
                  GFitsImage(G_BITPIX, naxes)
 {
-    // Initialise class members for clean destruction
+    // Initialise class members
     init_members();
 
     // Construct data
@@ -185,6 +185,39 @@ GFitsImageShort::GFitsImageShort(const std::vector<int>& naxes,
 
 
 /***********************************************************************//**
+ * @brief Type conversion constructor
+ *
+ * @param[in] image FITS image.
+ *
+ * This constructor performs the conversion of any image type into a short
+ * integer image.
+ ***************************************************************************/
+GFitsImageShort::GFitsImageShort(const GFitsImage& image) :
+                 GFitsImage(image)
+{
+    // Initialise class members
+    init_members();
+
+    // Copy pixels
+    if (m_num_pixels > 0) {
+        m_pixels = new short[m_num_pixels];
+        for (int i = 0; i < m_num_pixels; ++i) {
+            m_pixels[i] = (short)image.pixel(i);
+        }
+    }
+
+    // Set number of bits per pixel
+    m_bitpix = G_BITPIX;
+
+    // Update header card
+    header()["BITPIX"].value(G_BITPIX);
+
+    // Return
+    return;
+}
+
+
+/***********************************************************************//**
  * @brief Copy constructor
  *
  * @param[in] image FITS image.
@@ -192,7 +225,7 @@ GFitsImageShort::GFitsImageShort(const std::vector<int>& naxes,
 GFitsImageShort::GFitsImageShort(const GFitsImageShort& image) :
                  GFitsImage(image)
 {
-    // Initialise class members for clean destruction
+    // Initialise class members
     init_members();
 
     // Copy members
diff --git a/src/fits/GFitsImageULong.cpp b/src/fits/GFitsImageULong.cpp
index a829d0c..ad3c359 100644
--- a/src/fits/GFitsImageULong.cpp
+++ b/src/fits/GFitsImageULong.cpp
@@ -1,7 +1,7 @@
 /***************************************************************************
  *          GFitsImageULong.cpp - Unsigned long image FITS class           *
  * ----------------------------------------------------------------------- *
- *  copyright (C) 2010-2016 by Juergen Knoedlseder                         *
+ *  copyright (C) 2010-2017 by Juergen Knoedlseder                         *
  * ----------------------------------------------------------------------- *
  *                                                                         *
  *  This program is free software: you can redistribute it and/or modify   *
@@ -54,7 +54,7 @@
  ***************************************************************************/
 GFitsImageULong::GFitsImageULong(void) : GFitsImage()
 {
-    // Initialise class members for clean destruction
+    // Initialise class members
     init_members();
 
     // Return
@@ -73,7 +73,7 @@ GFitsImageULong::GFitsImageULong(void) : GFitsImage()
 GFitsImageULong::GFitsImageULong(const int& nx, const unsigned long* pixels) :
                  GFitsImage(G_BITPIX, nx)
 {
-    // Initialise class members for clean destruction
+    // Initialise class members
     init_members();
 
     // Construct data
@@ -97,7 +97,7 @@ GFitsImageULong::GFitsImageULong(const int& nx, const int& ny,
                                  const unsigned long* pixels) :
                  GFitsImage(G_BITPIX, nx, ny)
 {
-    // Initialise class members for clean destruction
+    // Initialise class members
     init_members();
 
     // Construct data
@@ -122,7 +122,7 @@ GFitsImageULong::GFitsImageULong(const int& nx, const int& ny, const int& nz,
                                  const unsigned long* pixels) :
                  GFitsImage(G_BITPIX, nx, ny, nz)
 {
-    // Initialise class members for clean destruction
+    // Initialise class members
     init_members();
 
     // Construct data
@@ -149,7 +149,7 @@ GFitsImageULong::GFitsImageULong(const int& nx, const int& ny, const int& nz,
                                  const unsigned long* pixels) :
                  GFitsImage(G_BITPIX, nx, ny, nz, nt)
 {
-    // Initialise class members for clean destruction
+    // Initialise class members
     init_members();
 
     // Construct data
@@ -174,7 +174,7 @@ GFitsImageULong::GFitsImageULong(const std::vector<int>& naxes,
                                  const unsigned long*    pixels) :
                  GFitsImage(G_BITPIX, naxes)
 {
-    // Initialise class members for clean destruction
+    // Initialise class members
     init_members();
 
     // Construct data
@@ -186,6 +186,39 @@ GFitsImageULong::GFitsImageULong(const std::vector<int>& naxes,
 
 
 /***********************************************************************//**
+ * @brief Type conversion constructor
+ *
+ * @param[in] image FITS image.
+ *
+ * This constructor performs the conversion of any image type into an
+ * unsigned long integer image.
+ ***************************************************************************/
+GFitsImageULong::GFitsImageULong(const GFitsImage& image) :
+                 GFitsImage(image)
+{
+    // Initialise class members
+    init_members();
+
+    // Copy pixels
+    if (m_num_pixels > 0) {
+        m_pixels = new unsigned long[m_num_pixels];
+        for (int i = 0; i < m_num_pixels; ++i) {
+            m_pixels[i] = (unsigned long)image.pixel(i);
+        }
+    }
+
+    // Set number of bits per pixel
+    m_bitpix = G_BITPIX;
+
+    // Update header card
+    header()["BITPIX"].value(G_BITPIX);
+
+    // Return
+    return;
+}
+
+
+/***********************************************************************//**
  * @brief Copy constructor
  *
  * @param[in] image FITS image.
@@ -193,7 +226,7 @@ GFitsImageULong::GFitsImageULong(const std::vector<int>& naxes,
 GFitsImageULong::GFitsImageULong(const GFitsImageULong& image) :
                  GFitsImage(image)
 {
-    // Initialise class members for clean destruction
+    // Initialise class members
     init_members();
 
     // Copy members
diff --git a/src/fits/GFitsImageUShort.cpp b/src/fits/GFitsImageUShort.cpp
index d36aa9d..cad0589 100644
--- a/src/fits/GFitsImageUShort.cpp
+++ b/src/fits/GFitsImageUShort.cpp
@@ -1,7 +1,7 @@
 /***************************************************************************
  *         GFitsImageUShort.cpp - Unsigned short FITS image class          *
  * ----------------------------------------------------------------------- *
- *  copyright (C) 2010-2016 by Juergen Knoedlseder                         *
+ *  copyright (C) 2010-2017 by Juergen Knoedlseder                         *
  * ----------------------------------------------------------------------- *
  *                                                                         *
  *  This program is free software: you can redistribute it and/or modify   *
@@ -54,7 +54,7 @@
  ***************************************************************************/
 GFitsImageUShort::GFitsImageUShort(void) : GFitsImage()
 {
-    // Initialise class members for clean destruction
+    // Initialise class members
     init_members();
 
     // Return
@@ -74,7 +74,7 @@ GFitsImageUShort::GFitsImageUShort(const int& nx,
                                    const unsigned short* pixels) :
                   GFitsImage(G_BITPIX, nx)
 {
-    // Initialise class members for clean destruction
+    // Initialise class members
     init_members();
 
     // Construct data
@@ -98,7 +98,7 @@ GFitsImageUShort::GFitsImageUShort(const int& nx, const int& ny,
                                    const unsigned short* pixels) :
                   GFitsImage(G_BITPIX, nx, ny)
 {
-    // Initialise class members for clean destruction
+    // Initialise class members
     init_members();
 
     // Construct data
@@ -123,7 +123,7 @@ GFitsImageUShort::GFitsImageUShort(const int& nx, const int& ny, const int& nz,
                                    const unsigned short* pixels) :
                   GFitsImage(G_BITPIX, nx, ny, nz)
 {
-    // Initialise class members for clean destruction
+    // Initialise class members
     init_members();
 
     // Construct data
@@ -150,7 +150,7 @@ GFitsImageUShort::GFitsImageUShort(const int& nx, const int& ny,
                                    const unsigned short* pixels) :
                   GFitsImage(G_BITPIX, nx, ny, nz, nt)
 {
-    // Initialise class members for clean destruction
+    // Initialise class members
     init_members();
 
     // Construct data
@@ -175,7 +175,7 @@ GFitsImageUShort::GFitsImageUShort(const std::vector<int>& naxes,
                                    const unsigned short*   pixels) :
                   GFitsImage(G_BITPIX, naxes)
 {
-    // Initialise class members for clean destruction
+    // Initialise class members
     init_members();
 
     // Construct data
@@ -187,6 +187,39 @@ GFitsImageUShort::GFitsImageUShort(const std::vector<int>& naxes,
 
 
 /***********************************************************************//**
+ * @brief Type conversion constructor
+ *
+ * @param[in] image FITS image.
+ *
+ * This constructor performs the conversion of any image type into an
+ * unsigned short integer image.
+ ***************************************************************************/
+GFitsImageUShort::GFitsImageUShort(const GFitsImage& image) :
+                  GFitsImage(image)
+{
+    // Initialise class members
+    init_members();
+
+    // Copy pixels
+    if (m_num_pixels > 0) {
+        m_pixels = new unsigned short[m_num_pixels];
+        for (int i = 0; i < m_num_pixels; ++i) {
+            m_pixels[i] = (unsigned short)image.pixel(i);
+        }
+    }
+
+    // Set number of bits per pixel
+    m_bitpix = G_BITPIX;
+
+    // Update header card
+    header()["BITPIX"].value(G_BITPIX);
+
+    // Return
+    return;
+}
+
+
+/***********************************************************************//**
  * @brief Copy constructor
  *
  * @param[in] image FITS image.
@@ -194,7 +227,7 @@ GFitsImageUShort::GFitsImageUShort(const std::vector<int>& naxes,
 GFitsImageUShort::GFitsImageUShort(const GFitsImageUShort& image) :
                   GFitsImage(image)
 {
-    // Initialise class members for clean destruction
+    // Initialise class members
     init_members();
 
     // Copy members
diff --git a/test/test_GFits.py b/test/test_GFits.py
index 72ef420..f8ae2e8 100755
--- a/test/test_GFits.py
+++ b/test/test_GFits.py
@@ -148,6 +148,17 @@ class Test(gammalib.GPythonTestSuite):
         img8.extname("ULong")
         img9.extname("UShort")
 
+        # Test image types by checking the bitpix values
+        self.test_value(img1.bitpix(), 8)
+        self.test_value(img2.bitpix(), -64)
+        self.test_value(img3.bitpix(), -32)
+        self.test_value(img4.bitpix(), 32)
+        self.test_value(img5.bitpix(), 64)
+        self.test_value(img6.bitpix(), 10)
+        self.test_value(img7.bitpix(), 16)
+        self.test_value(img8.bitpix(), 40)
+        self.test_value(img9.bitpix(), 20)
+
         # Append images to FITS file
         fits.append(img1)
         fits.append(img2)
@@ -174,6 +185,17 @@ class Test(gammalib.GPythonTestSuite):
         # Re-open FITS file
         fits = gammalib.GFits(file1)
 
+        # Test image types by checking the bitpix values
+        self.test_value(fits[0].bitpix(), 8)
+        self.test_value(fits[1].bitpix(), -64)
+        self.test_value(fits[2].bitpix(), -32)
+        self.test_value(fits[3].bitpix(), 32)
+        self.test_value(fits[4].bitpix(), 64)
+        #self.test_value(fits[5].bitpix(), 10) # Not supported in older cfitsio
+        self.test_value(fits[5].bitpix(), 16)
+        self.test_value(fits[6].bitpix(), 40)
+        self.test_value(fits[7].bitpix(), 20)
+
         # Get double precision image, take square root of pixel and save in
         # another file
         img_double = fits.image("Double")
@@ -187,6 +209,26 @@ class Test(gammalib.GPythonTestSuite):
         # Close FITS file
         fits.close()
 
+        # Test type conversion constructors
+        img = gammalib.GFitsImageByte(img6)
+        self.test_value(img.bitpix(), 8)
+        img = gammalib.GFitsImageDouble(img1)
+        self.test_value(img.bitpix(), -64)
+        img = gammalib.GFitsImageFloat(img1)
+        self.test_value(img.bitpix(), -32)
+        img = gammalib.GFitsImageLong(img1)
+        self.test_value(img.bitpix(), 32)
+        img = gammalib.GFitsImageLongLong(img1)
+        self.test_value(img.bitpix(), 64)
+        img = gammalib.GFitsImageSByte(img1)
+        self.test_value(img.bitpix(), 10)
+        img = gammalib.GFitsImageShort(img1)
+        self.test_value(img.bitpix(), 16)
+        img = gammalib.GFitsImageULong(img1)
+        self.test_value(img.bitpix(), 40)
+        img = gammalib.GFitsImageUShort(img1)
+        self.test_value(img.bitpix(), 20)
+
         # Return
         return
 
@@ -355,4 +397,4 @@ class Test(gammalib.GPythonTestSuite):
 
         # Return
         return
-        
\ No newline at end of file
+