how to compile Leptonica library for windows x64 bit using VS2010?

I can build Leptonica libraries(DLL) for 32-bit windows using VS2010 by the help of http://ift.tt/1KX2IfT . But when I change the Target into x64, I got below errors. How can I resolve this? Is it possible to compile the 32-bit source files in 64 bit?

2>tiffio.obj : error LNK2019: unresolved external symbol TIFFReadRGBAImageOriented referenced in function pixReadFromTiffStream 2>tiffio.obj : error LNK2019: unresolved external symbol TIFFReadScanline referenced in function pixReadFromTiffStream 2>tiffio.obj : error LNK2019: unresolved external symbol TIFFScanlineSize referenced in function pixReadFromTiffStream 2>tiffio.obj : error LNK2019: unresolved external symbol TIFFGetField referenced in function pixReadFromTiffStream