GNOME Scan

Hi everybody,

My work on flegita-gimp does not mean i forgot OCR which is, IMHO, the first class feature of scanning. Writing AbiScan clears my vision on how to design Gnome OCR UI. Before writing AbiScan, i was wondering how to integrate OCR in Gnome Scan. I was really worried because Gnome Scan is designed to pass image (as GeglBuffer) to application, not text or HTML or wathever OCR output format. I decided to write AbiScan and use ocropus directly instead of through Gnome Scan.

This lead me to find the way Gnome will receive OCR and OCR UI. AbiScan use ocropus command line tool, the idea is to use a library providing common OCR UI instead. This library should be ship by OCRopus. Why OCRopus and not Gnome Scan ? Because i think this library depends more on OCRopus and not on Gnome Scan. I may provide an OCR sink in Gnome Scan which help pluging Gnome Scan and OCRopus, but that’s not all the UI and OCR interaction part which should heavily rely on OCRopus itself, just like OCRopus command line tool.

Publishing AbiScan seems to have revealed questions from users. At the risk of repeating OCRopus website, let me explain a bit of OCRopus. OCRopus is not an OCR engine. OCRopus is a document analysis and OCR system. Instead of rewriting its own OCR engine, it uses existing one, especially tesseract, but more are to come. The difference between OCRopus and an OCR engine is exactly the same as between HTML and plain/text. HTML contains semantic, formatting and test itself while plain/text contains only … text ! So, if ever you read a comparision between OCRopus and e.g. gocr or ocrad, you can laught at it. Well, in fact, ocrad has a minimal layout analyser for text column, but that’s not as advanced as OCRopus layout analyser.

Regards,
Étienne.

Hi all,

Resulting in about one week of lazy effort, i reach to produce a preliminary version of AbiScan on top of OCRopus. I produced a screencast video of direct OCR import into Abiword Frame. This is very buggy, but very exciting too :).

I must thanks #abiword people, especially Dominic Lachowicz, Marc Mauer, Martin Sevior, jean, sum1 and Hubert Figuière. Thanks goes to OCRopus and Gegl people for their work and advices.

I provide AbiScan patch against abiword-plugins SVN. The plugins does not work if abiword use G_MODULE_BIND_LAZY flags, this is a bug in abiscan, not abiword. I provide a patch against abiword SVN removing g_module_open flags, but it will hopefully never be merged.

If you want to try it, follow the following steps :

1. Install tesseract-ocr from SVN, with the patch i provide in tesseract BTS ;
2. Install ocropus ;
3. Install Gegl SVN ;
4. Install Gnome Scan SVN ;
5. Install abiword SVN with g-module-open-flags.diff patch ;
6. Install abiword-plugins SVN with abiscan.diff patch ;
7. Launch Abiword
8. Launch Insert > Import from scanner and follow the steps.

Warning : that’s really buggy.

• Gnome Scan does not handle device list very well if you launch several times the dialog.
• OCRopus does not provide any API, so the plugin use system() and isn’t able to monitor progress. OCRopus might take very long time.
• Sometimes, it eats tons of memory.
• Currently, it lose formating, that’s due to a HTML import pasteFromBuffer() bug. I had to make a choice between paste into existing document losing formating, or open directly tmp OCRopus HTML directly.

Bug reports are very welcome, please file bugs to gnome-scan product in Gnome bugzilla, for the abiscan component. Note that OCRopus prefer 150dpi images.

Anyway, that’s a rought draft with the key feature provided by Gnome Scan and OCRopus : tight integration into application and advanced OCR.

becomes

Regards,
Étienne

—
E Ultreïa !