(Optional) Building the liblept library

Assuming that you’ve downloaded or built the requisite image libraries, building liblept 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-8c\
     leptonica-1.68\
     lib\
     libtiff-3.9.4\
     lpng143\
     zlib\
   

2. Download the Microsoft Visual Studio 2008 build package from here. Extract the archive to the BuildFolder\leptonica-1.68 directory. You should now have:

   BuildFolder\
     giflib-4.1.6\
     include\
     jpeg-8c\
     leptonica-1.68\
       vs2008\
     lib\
     libtiff-3.9.4\
     lpng143\
     zlib\
   

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 leptonica-1.68\src to BuildFolder\include\leptonica.

5. Open BuildFolder\leptonica-1.68\vs2008\leptonica.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 "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 "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 "LIBLEPT_EXPORTS" /D "L_LITTLE_ENDIAN"
   /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 "LIBLEPT_EXPORTS" /D "L_LITTLE_ENDIAN"
   /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
   

   DLL releases set the following linker options:

   /VERSION:1.68
   

7. Right-click liblept168 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	liblept168-static-mtdll-debug.lib	liblept168-static-mtdll.lib
   DLL	liblept168d.lib (import library) liblept168d.dll	liblept168.lib (import library) liblept168.dll