scanpdf revisions and enhancements

[dkfurrow]

Hi Virantha;

I am a recent convert to linux, and I found your post of getting the one-touch scan enabled on scansnap enabled, and also the scanpdf project.

I found that some of the base commands (scan, unpaper) didn't work on my system (LM 18), so applied some small changes to get those functions working again. Also, I noticed the is_blank method wasn't applying the blank_threshold variable, so fixed that, as well as the application of the --face-up argument. Beyond that, I applied the following enhancements:

• Implemented a deskew method from here. For me at least, that seemed to work well, but it's possibly redundent to unpaper. I'm not sure how to change the package information to ensure that the executable is included...right now it's simply placed in the scanpdf directory.
• Added text-recognition from pdfsandwich...I have used that in some instances, seem to work reasonably well, so added it as an option.
• Introduced an option to save via a wx-gui save file dialog...for me, I mostly just scan a set of documents, then choose where they go after completion, as in the original windows drivers for the scansnap. Note that the use of this option does require that DISPLAY and XAUTHORITY environment variables are set in the calling scanbd script...I didn't document that, but would be happy to do so.
• Implemented multi-threading for page processing. At least for me, that speeded up execution considerably.

Anyway, this is my first contribution to a defined pip package, so I apologize in advance if I missed any documentation or package build steps...For example, It was a little unclear to me how I should include the wx requirement. Also, I wasn't sure what sort of tests to include, but I did add a simple run script with various options that I used in my own testing. In any case, I wanted to attempt to make a contribution here, since your original work was quite useful to me. If you have any questions or would like me to make further adjustments in my fork, my email is dkfurrow@gmail.com.

Thanks,
Dale