Sciweavers i2OCR is another free online service that can OCR image files in a number of languages, including traditional and simplified Chinese (see the post on using Google Docs to OCR Chinese); no sign up is required. A pdf has to be converted to an image file before it can be uploaded. Sciweavers provides another online tool to do this (follow the instructions on the i2OCR page), but I’ve also just opened a pdf in Preview (the default Mac pdf/image viewer) and exported it as a jpg.
Once the OCR is complete, you’ll see a download icon plus a selectable text area containing the editable text next to an image of your scan. The download button saves a file with a .doc suffix. There’s something peculiar about the doc, though, because neither Pages nor Google Docs could open it, although TextEdit did.
Sciweavers OCR is noticeably slower than Google Docs; one page took over two minutes. But the results were comparable. If you need to scan Chinese for free and do not have (or do not want to log into) a Google account, then Sciweavers i2OCR is a very good alternative.
Stay tuned for fuller coverage of the Chinese OCR showdown.