(Optional) Building the leptonlib library

Assuming that you’ve downloaded or built the requisite image libraries, building leptonlib itself is straightforward since a Visual Studio solution file is provided.

1. Download the latest version of leptonica from here. Extract the archive to the BuildFolder directory. You should now have:

   BuildFolder\
     giflib-4.1.6\
     include\
     jpeg-8b\
     leptonlib-1.67\
     lib\
     libtiff-3.9.4\
     lpng143\
     zlib\
   

2. Download the Microsoft Visual Studio 2008 build package from here. Extract the archive to the BuildFolder\leptonlib-1.67 directory. You should now have:

   BuildFolder\
     include\
     leptonlib-1.67\
       vs2008\
     lib\
     tiff-3.9.4\
   

3. leptprotos.h has the wrong declaration for setPixMemoryManager() under Windows. Change it from:

   LEPT_DLL extern void setPixMemoryManager ( void * ( allocator (size_t ) ), void  ( deallocator ( void * ) ) );
   

   to:

   LEPT_DLL extern void setPixMemoryManager (void *((*allocator)(size_t)), void ((*deallocator)(void *)) );
   

4. Copy all the .h header files from leptonlib-1.67\src to BuildFolder\include\leptonica.

5. Open BuildFolder\leptonlib-1.67\vs2008\leptonlib.sln with Visual Studio 2008.

6. Select the desired build configuration (either LIB Debug, LIB Release, DLL Debug, or DLL Release and probably Win32).

   LIB Debug builds use the following C compiler options:

   /Od /I "..\..\include"
   /D "WIN32" /D "_DEBUG" /D "_LIB" /D "L_LITTLE_ENDIAN"
   /D "snprintf=_snprintf" /D "XMD_H"
   /FD /EHsc /RTC1 /MDd /Fo"LIB Debug\\" /Fd"LIB Debug\vc90.pdb"
   /W3 /nologo /c /Z7 /errorReport:prompt
   

   LIB Release builds use the following C compiler options:

   /O2 /I "..\..\include"
   /D "WIN32" /D "NDEBUG" /D "_LIB" /D "L_LITTLE_ENDIAN"
   /D "snprintf=_snprintf" /D "XMD_H" /D "NO_CONSOLE_IO"
   /FD /EHsc /MD /Fo"LIB Release\\" /Fd"LIB Release\vc90.pdb"
   /W3 /nologo /c /errorReport:prompt
   

   DLL Debug builds use the following C compiler options:

   /Od /I "..\..\include"
   /D "WIN32" /D "_DEBUG" /D "_USRDLL" /D "_WINDLL"
   /D "LEPTONLIB_EXPORTS" /D "L_LITTLE_ENDIAN"
   /D "snprintf=_snprintf" /D "XMD_H"
   /FD /EHsc /RTC1 /MDd /Fo"DLL Debug\\" /Fd"DLL Debug\vc90.pdb"
   /W3 /nologo /c /Z7 /errorReport:prompt
   

   DLL Release builds use the following C compiler options:

   /O2 /I "..\..\include"
   /D "WIN32" /D "NDEBUG" /D "_USRDLL" /D "_WINDLL"
   /D "LEPTONLIB_EXPORTS" /D "L_LITTLE_ENDIAN"
   /D "snprintf=_snprintf" /D "XMD_H" /D "NO_CONSOLE_IO"
   /FD /EHsc /MD /Fo"DLL Release\\" /Fd"DLL Release\vc90.pdb"
   /W3 /nologo /c /errorReport:prompt
   

   All configurations turn off some warnings with the following options:

   /wd4244 /wd4305 /wd4018 /wd4267 /wd4996
   

7. Right-click leptonlib-1.67 in the Solution Explorer and Choose Build or Rebuild from the context menu (Choosing Build ‣ Build Solution (F6) or Build ‣ Rebuild Solution from the Visual Studio menubar will result in ioformats_reg also being built). The resultant library will automatically be copied to BuildFolder\lib.

   The libraries are named as follows:

   	Debug Builds	Release Builds
   Static library	leptonlib-static-mtdll-debug.lib	leptonlib-static-mtdll.lib
   DLL	leptonlibd.lib (import library) leptonlibd.dll	leptonlib.lib (import library) leptonlib.dll