I think Tesseract is the best (free) command-line based OCR software. Unfortunately there doesn't appear to be a Windows 7 64-bit binary available so you'd have to compile it yourself; here are the instructions for doing so (taken from a comment on the Tesseract FAQ page):
Download tesseract 2.04. Unpack it. In this example I've unpacked to
C:\projects\tesseract-2.04. Windows 7
still doesn't understand .tar.gz out
of the box. My recommendation is to
get a copy of 7-Zip.
Download your required language files. I need German and English. I
unpack these to the tessdata
subdirectory of
C:\projects\tesseract-2.04\tessdata.
Install libtiff. On my (64 bit) system the suggested install directory
is C:\Program Files (x86)\GnuWin32?.
Underneath this directory are a bunch
of subdirectories containing files
we'll need to compile tesseract with
tiff support, namely include, bin and
lib.
Add C:\Program Files (x86)\GnuWin32?\bin to your PATH
environment variable so that the
output tesseract.exe can find the
libtiff dll. Restart.
Open the vc solution (tesseract.sln)
Change the solution configuration to "Release" mode. Note that if you
later change back to Debug mode,
you'll need to set up all the
following again...
In the solution explorer right click the solution node (Solution
'tesseract') and click "Properties".
Change to "Configuration Properties"
and select "Release" configuration
from the dropdown at the top of the
window. Navigate to: Tools -> Options
-> Projects and Solutions -> VC++ Directories Here we'll be adding the
full paths for the subdirectories lib
and include from the libtiff install
so that VC can find the required
header (.h) and static library (.lib)
files. In this example they are:
$(ProgramFiles?)\GnuWin32?\include
$(ProgramFiles?)\GnuWin32?\lib as I'm
using an environment variable. I could
however just have written them as
C:\Program Files
(x86)\GnuWin32?\include.
Change the "Show Directories For"
dropdown to "Include files". Add the
following:
$(ProgramFiles?)\GnuWin32?\include
Now change the "Show Directories For"
dropdown to "Library files". Add the
following:
$(ProgramFiles?)\GnuWin32?\lib
Now open the project properties window for the tesseract project (not
the solution). In the solution
explorer right click the tesseract
project and click properties. Navigate
the horrendous list of options to
Configuration Properties -> C/C++ ->
Preprocessor and add HAVE_LIBTIFF to
the list of Preprocessor Definitions.
This causes a bunch of #includes to be
enabled in the code.
You also want to add an "Additional dependency". go to the "Additional
dependencies" section for the project
properties and add libtiff.lib.
Build the solution. Watch the error list. If you get a bunch of
LNK2109 errors, that means the linker
can't find something tesseract
references. You're missing a reference
to one of the paths from libtiff. If
you get an error mentioning mt.exe,
you've possibly encountered a bug in
the sdk. Just try building again. see
http://connect.microsoft.com/VisualStudio/feedback/ViewFeedback.aspx?FeedbackID=106634
for more info.
If/when the solution builds
successfully, you'll have a
tesseract.exe file in the same
directory as the tesseract solution
file. drag you multipage compressed
tiff here and try running tesseract.
for example, if your tiff is called
in.tif and you want to output text to
out.txt, and the documents' language
is German then your command line would
look like:
tesseract.exe in.tif out -l deu The
output file will have .txt appended to
it by tesseract. If you're just
translating English text then you can
leave off the -l option, as tesseract
assumes "eng" if you don't specify
anything. If your tif file has the
file extension .tiff, then tesseract
will crap itself thusly:
C:\projects\tesseract-2.04>tesseract.exe
in.tiff out -l deu Tesseract Open
Source OCR Engine
name_to_image_type:Error:Unrecognized
image type:in.tiff
IMAGE::read_header:Error:Can't read
this image type:in.tiff
tesseract.exe:Error:Read of file
failed:in.tiff
Hopefully (fingers crossed, heh)
you've now got an OCR'd out.txt file
sitting in C:\projects\tesseract-2.04.
