Do you want to translate a scanned or downloaded chess diagram (jpg, gif, bmp)
into a computer readable chess file format (FEN, EPD, PGN, BRT, TeX, ...)?
Then please feel free to use Chess Scan intelligent as 'OCR' tool.
It's simple and free.
http://www.fairychess.com/ChessScan.html
Disclaimer:
Please respect any copyright laws.
Special thanks!