In my experience, it is very important that the contrast not only be
very good but also that the characters can be easily distinguished
from the background and that the characters are generally repeatable
and unique. I've had problems with characters "smearing" into the
background so that the OCR can't tell where the background ends and
the character begins.
Beyond the standard NI OCR stuff, you can use a database to map
incorrect whole words to correct whole ones in OCR but this only works
when there is a set of unique words that are significantly different
from each other. It doesn't work on numbers since any number is
generally as likely as any other.
It may be worthwhile to invest in higher quality acquisition equipment
to improve the image quality. If your video source itself is poor
quality, then it won't matter though.
Douglas De Clue
ddeclue@bellsouth.net
nestor
wrote in message news:<506500000005000000F68B0000-1023576873000@exchange.ni.com>...
> Ernest,
>
> As "labviewguru" mentioned a screenshot will help a lot to determine
> if the problem is the image quality. However if you can't post this
> image then please review the following links I'm attaching here. They
> talk about OCR and most important, about Filtering, which is mostly
> used in Vision for image enhancement, noise reduction, sharpen an
> image, etc. Please review the links mentioned below and apply some
> filtering techniques to your image. This may help a lot, personally
> I've used OCR software and I have required in most cases to apply
> filtering before running the OCR functions.
>
>
> href="http://zone.ni.com/devzone/conceptd.nsf/webmain/E69D110920B99E838625685E0081B881?opendocumen...
>
> href="http://zone.ni.com/devzone/devzone.nsf/webcategories/605B55C3100D02188625685E0076C928?opendo...
>
> href="http://zone.ni.com/devzone/devzone.nsf/webcategories/E28E087D201C1AD48625685E00824E3C?opendo...
>
> Here at the Developer Zone, inside the Development Library you will
> find in the Vision chapter a lot of information that will be helpful
> for your development. Please review it. In case you require further
> assistance you can keep posting questions here at the Discussion Forum
> or give us a call/email (www.ni.com/ask).
>
> Good luck!
>
> Nestor Sanchez
> IMAQ/Motion Support
> National Instruments
