将文档扫描成 PDF 格式很容易，但是能够把PDF转换过来吗？Gscan2pdf 采用光学识别软件对您的 PDF 文档进行扫描并将图像转换为文字。
gscan2pdf 1.0
gscan2pdf 1.0 改进变化：
* Deal with version information from PDF::API2
* Suppressed “End of file reached” message.
Closes Debian bug #622844
Thanks to Sebastian Schmidt for the patch
* Switch to OO interface for File::Temp, thus automatically clearing up
unneeded temporary files. Closes Debian bug #563461
* Removed all blocking progress dialogs
Closes Debian bug #577144
* + Spinbuttons to crop dialog
* + Edit/Select/No OCR
* + Edit/Clear OCR
Closes Debian bug #602578
* Combined Import and Open dialogs
Closes Debian bug #617886
* + Tesseract 3.01 support
* Fix embedding of UTF-8 OCR output
PPA源安装，打开终端输入命令：
sudo add-apt-repository ppa:jeffreyratcliffe/ppa
sudo apt-get update
sudo apt-get install gscan2pdf
