Made load_image() support GIF files.

dlib/CMakeLists.txt

@@ -14,9 +14,13 @@ include(use_cpp_11.cmake)
 
 set(CPACK_PACKAGE_VERSION_MAJOR "18")
 set(CPACK_PACKAGE_VERSION_MINOR "18")
-set(CPACK_PACKAGE_VERSION_PATCH "99")
+set(CPACK_PACKAGE_VERSION_PATCH "100")
 set(VERSION ${CPACK_PACKAGE_VERSION_MAJOR}.${CPACK_PACKAGE_VERSION_MINOR}.${CPACK_PACKAGE_VERSION_PATCH})
-set(DLIB_VERSION ${VERSION} PARENT_SCOPE)
+# Set DLIB_VERSION in the including CMake file so they can use it to do whatever they want. 
+get_directory_property(has_parent PARENT_DIRECTORY)
+if(has_parent)
+   set(DLIB_VERSION ${VERSION} PARENT_SCOPE)
+endif()
 
 set(CMAKE_LEGACY_CYGWIN_WIN32 0) # Remove when CMake >= 2.8.4 is required
 # Suppress cmake warnings about changes in new versions.
@@ -68,6 +72,8 @@ if (NOT TARGET dlib)
    "Disable this if you don't want to use NVIDIA CUDA" )
    set (DLIB_PNG_SUPPORT_STR
    "Disable this if you don't want to link against libpng" )
+   set (DLIB_GIF_SUPPORT_STR
+   "Disable this if you don't want to link against libgif" )
    set (DLIB_JPEG_SUPPORT_STR
    "Disable this if you don't want to link against libjpeg" )
    set (DLIB_LINK_WITH_SQLITE3_STR
@@ -103,6 +109,7 @@ if (NOT TARGET dlib)
       option(DLIB_USE_LAPACK ${DLIB_USE_LAPACK_STR} OFF)
       option(DLIB_USE_CUDA ${DLIB_USE_CUDA_STR} OFF)
       option(DLIB_PNG_SUPPORT ${DLIB_PNG_SUPPORT_STR} OFF)
+      option(DLIB_GIF_SUPPORT ${DLIB_GIF_SUPPORT_STR} OFF)
       #option(DLIB_USE_FFTW ${DLIB_USE_FFTW_STR} OFF)
    else()
       option(DLIB_JPEG_SUPPORT ${DLIB_JPEG_SUPPORT_STR} ON)
@@ -111,6 +118,7 @@ if (NOT TARGET dlib)
       option(DLIB_USE_LAPACK ${DLIB_USE_LAPACK_STR} ON)
       option(DLIB_USE_CUDA ${DLIB_USE_CUDA_STR} ON)
       option(DLIB_PNG_SUPPORT ${DLIB_PNG_SUPPORT_STR} ON)
+      option(DLIB_GIF_SUPPORT ${DLIB_GIF_SUPPORT_STR} ON)
       #option(DLIB_USE_FFTW ${DLIB_USE_FFTW_STR} ON)
    endif()
    toggle_preprocessor_switch(DLIB_JPEG_SUPPORT)
@@ -118,6 +126,7 @@ if (NOT TARGET dlib)
    toggle_preprocessor_switch(DLIB_USE_LAPACK)
    toggle_preprocessor_switch(DLIB_USE_CUDA)
    toggle_preprocessor_switch(DLIB_PNG_SUPPORT) 
+   toggle_preprocessor_switch(DLIB_GIF_SUPPORT) 
    #toggle_preprocessor_switch(DLIB_USE_FFTW)
 
 
@@ -275,6 +284,17 @@ if (NOT TARGET dlib)
 
       INCLUDE (CheckFunctionExists)
 
+      if (DLIB_GIF_SUPPORT)
+         find_package(GIF QUIET)
+         if (GIF_FOUND)
+            include_directories(${GIF_INCLUDE_DIR})
+            set (dlib_needed_libraries ${dlib_needed_libraries} ${GIF_LIBRARY})
+         else()
+            set(DLIB_GIF_SUPPORT OFF CACHE STRING ${DLIB_GIF_SUPPORT_STR} FORCE )
+            toggle_preprocessor_switch(DLIB_GIF_SUPPORT)
+         endif()
+      endif()
+
       if (DLIB_PNG_SUPPORT)
          # try to find libpng 
          find_package(PNG QUIET)

dlib/config.h

@@ -14,10 +14,11 @@
 //#define DLIB_NO_GUI_SUPPORT
 //#define DLIB_ENABLE_STACK_TRACE
 
-// You should also consider telling dlib to link against libjpeg, libpng, fftw, CUDA, and a
-// BLAS and LAPACK library.  To do this you need to uncomment the following #defines.
+// You should also consider telling dlib to link against libjpeg, libpng, libgif, fftw, CUDA, 
+// and a BLAS and LAPACK library.  To do this you need to uncomment the following #defines.
 // #define DLIB_JPEG_SUPPORT
 // #define DLIB_PNG_SUPPORT
+// #define DLIB_GIF_SUPPORT
 // #define DLIB_USE_FFTW
 // #define DLIB_USE_BLAS
 // #define DLIB_USE_LAPACK

dlib/config.h.in

@@ -14,10 +14,11 @@
 #cmakedefine DLIB_NO_GUI_SUPPORT
 #cmakedefine DLIB_ENABLE_STACK_TRACE
 
-// You should also consider telling dlib to link against libjpeg, libpng, fftw, CUDA, and a
-// BLAS and LAPACK library.  To do this you need to uncomment the following #defines.
+// You should also consider telling dlib to link against libjpeg, libpng, libgif, fftw, CUDA, 
+// and a BLAS and LAPACK library.  To do this you need to uncomment the following #defines.
 #cmakedefine DLIB_JPEG_SUPPORT
 #cmakedefine DLIB_PNG_SUPPORT
+#cmakedefine DLIB_GIF_SUPPORT
 #cmakedefine DLIB_USE_FFTW
 #cmakedefine DLIB_USE_BLAS
 #cmakedefine DLIB_USE_LAPACK

dlib/image_loader/load_image.h

@@ -10,6 +10,9 @@
 #include "image_loader.h"
 #include <fstream>
 #include <sstream>
+#ifdef DLIB_GIF_SUPPORT
+#include <gif_lib.h>
+#endif
 
 namespace dlib
 {
@@ -21,6 +24,7 @@ namespace dlib
             JPG,
             PNG,
             DNG,
+            GIF,
             UNKNOWN
         };
 
@@ -45,11 +49,15 @@ namespace dlib
                 return BMP;
             else if(buffer[0]=='D' && buffer[1]=='N' && buffer[2] == 'G') 
                 return DNG;
+            else if(buffer[0]=='G' && buffer[1]=='I' && buffer[2] == 'F') 
+                return GIF;
 
             return UNKNOWN;
         }
     };
 
+// ----------------------------------------------------------------------------------------
+
     template <typename image_type>
     void load_image (
         image_type& image,
@@ -66,6 +74,54 @@ namespace dlib
 #endif
 #ifdef DLIB_JPEG_SUPPORT
             case image_file_type::JPG: load_jpeg(image, file_name); return;
+#endif
+#ifdef DLIB_GIF_SUPPORT
+            case image_file_type::GIF: 
+            {
+                image_view<image_type> img(image);
+                GifFileType* gif = DGifOpenFileName(file_name.c_str());
+                try
+                {
+                    if (gif == 0)
+                        throw image_load_error("Couldn't open file " + file_name);
+                    if (DGifSlurp(gif) != GIF_OK)
+                        throw image_load_error("Error reading from " + file_name);
+
+                    if (gif->ImageCount != 1)   throw image_load_error("Dlib only supports reading GIF files containing one image.");
+                    if (gif->SColorMap == 0)    throw image_load_error("Unsupported GIF format 1.");
+                    if (gif->SavedImages == 0)  throw image_load_error("Unsupported GIF format 2.");
+                    if (gif->SavedImages->ImageDesc.Width != gif->SWidth)   throw image_load_error("Unsupported GIF format 3.");
+                    if (gif->SavedImages->ImageDesc.Height != gif->SHeight) throw image_load_error("Unsupported GIF format 4.");
+                    if (gif->SColorMap->ColorCount != 256)  throw image_load_error("Unsupported GIF format 5.");
+                    if (gif->SColorMap->BitsPerPixel != 8)  throw image_load_error("Unsupported GIF format 6.");
+                    if (gif->SavedImages->RasterBits == 0)  throw image_load_error("Unsupported GIF format 7.");
+                    if (gif->SColorMap->Colors == 0)        throw image_load_error("Unsupported GIF format 8.");
+
+                    img.set_size(gif->SHeight, gif->SWidth);
+                    unsigned char* raster = gif->SavedImages->RasterBits;
+                    GifColorType* colormap = gif->SColorMap->Colors;
+                    for (long r = 0; r < img.nr(); ++r)
+                    {
+                        for (long c = 0; c < img.nc(); ++c)
+                        {
+                            rgb_pixel p;
+                            p.red = colormap[*raster].Red;
+                            p.green = colormap[*raster].Green;
+                            p.blue = colormap[*raster].Blue;
+                            assign_pixel(img[r][c], p);
+                            ++raster;
+                        }
+                    }
+                    DGifCloseFile(gif);
+                }
+                catch(...)
+                {
+                    if (gif)
+                        DGifCloseFile(gif);
+                    throw;
+                }
+                return;
+            }
 #endif
             default:  ;
         }
@@ -78,11 +134,11 @@ namespace dlib
                     "Do this by following the instructions at http://dlib.net/compile.html.\n\n";
 #ifdef _MSC_VER
             sout << "Note that you must cause DLIB_JPEG_SUPPORT to be defined for your entire project.\n";
-            sout << "So don't #define it in one file, add it to the C/C++->Preprocessor->Preprocessor Definitions\n";
+            sout << "So don't #define it in one file. Instead, add it to the C/C++->Preprocessor->Preprocessor Definitions\n";
             sout << "field in Visual Studio's Property Pages window so it takes effect for your entire application.";
 #else
             sout << "Note that you must cause DLIB_JPEG_SUPPORT to be defined for your entire project.\n";
-            sout << "So don't #define it in one file, use a compiler switch like -DDLIB_JPEG_SUPPORT\n";
+            sout << "So don't #define it in one file. Instead, use a compiler switch like -DDLIB_JPEG_SUPPORT\n";
             sout << "so it takes effect for your entire application.";
 #endif
             throw image_load_error(sout.str());
@@ -95,11 +151,27 @@ namespace dlib
                     "Do this by following the instructions at http://dlib.net/compile.html.\n\n";
 #ifdef _MSC_VER
             sout << "Note that you must cause DLIB_PNG_SUPPORT to be defined for your entire project.\n";
-            sout << "So don't #define it in one file, add it to the C/C++->Preprocessor->Preprocessor Definitions\n";
+            sout << "So don't #define it in one file. Instead, add it to the C/C++->Preprocessor->Preprocessor Definitions\n";
             sout << "field in Visual Studio's Property Pages window so it takes effect for your entire application.\n";
 #else
             sout << "Note that you must cause DLIB_PNG_SUPPORT to be defined for your entire project.\n";
-            sout << "So don't #define it in one file, use a compiler switch like -DDLIB_PNG_SUPPORT\n";
+            sout << "So don't #define it in one file. Instead, use a compiler switch like -DDLIB_PNG_SUPPORT\n";
+            sout << "so it takes effect for your entire application.";
+#endif
+            throw image_load_error(sout.str());
+        }
+        else if (im_type == image_file_type::GIF)
+        {
+            std::ostringstream sout;
+            sout << "Unable to load image in file " + file_name + ".\n" +
+                    "You must #define DLIB_GIF_SUPPORT and link to libgif to read GIF files.\n\n";
+#ifdef _MSC_VER
+            sout << "Note that you must cause DLIB_GIF_SUPPORT to be defined for your entire project.\n";
+            sout << "So don't #define it in one file. Instead, add it to the C/C++->Preprocessor->Preprocessor Definitions\n";
+            sout << "field in Visual Studio's Property Pages window so it takes effect for your entire application.\n";
+#else
+            sout << "Note that you must cause DLIB_GIF_SUPPORT to be defined for your entire project.\n";
+            sout << "So don't #define it in one file. Instead, use a compiler switch like -DDLIB_GIF_SUPPORT\n";
             sout << "so it takes effect for your entire application.";
 #endif
             throw image_load_error(sout.str());
@@ -110,6 +182,8 @@ namespace dlib
         }
     }
 
+// ----------------------------------------------------------------------------------------
+
 }
 
 #endif // DLIB_LOAd_IMAGE_Hh_ 

dlib/image_loader/load_image_abstract.h

@@ -3,8 +3,6 @@
 #undef DLIB_LOAd_IMAGE_ABSTRACT_
 #ifdef DLIB_LOAd_IMAGE_ABSTRACT_
 
-#include "load_image_abstract.h"
-#include "../string.h"
 #include "../image_processing/generic_image.h"
 
 namespace dlib
@@ -19,10 +17,13 @@ namespace dlib
             - image_type == an image object that implements the interface defined in
               dlib/image_processing/generic_image.h 
         ensures
-            - This function looks at the file extensions and file headers to try and figure
-              out what kind of image format is inside the given file.  It then calls one of
-              load_png(), load_jpeg(), load_bmp(), or load_dng() as appropriate and stores
-              the resulting image into #image.
+            - This function loads an image from disk, in the indicated file file_name, and
+              writes it to the indicated image object.
+            - It is capable of reading the PNG, JPEG, BMP, GIF, and DNG image formats.  It
+              is always capable of reading BMP and DNG images.  However, for PNG, JPEG, and
+              GIF you must #define DLIB_PNG_SUPPORT, DLIB_JPEG_SUPPORT, and
+              DLIB_GIF_SUPPORT respectively and link your program to libpng, libjpeg, and
+              libgif respectively.
         throws
             - image_load_error
                 This exception is thrown if there is some error that prevents