I am having trouble reading a time stamp on a video using OCR 
Author Message
 I am having trouble reading a time stamp on a video using OCR

I am trying to read a time stamp that is overlaid on a video, using
OCR software, but it will not read it correctly I've tried the OCR
Preproccessing and Recognition Config VI's and neither have been able
to correct to problem I would appreciate some help


Sat, 08 Jan 2005 00:51:14 GMT  
 I am having trouble reading a time stamp on a video using OCR
Please post a screenshot of the image in question.

Also, please advise of how you are doing this.  I am assuming that you
are using IMAQ.

Your problem may be a matter of imaqe quality.  This is usually the
problem in these types of situations.  Be sure you have adequate
contrast.  If not, enhance it.



Sat, 08 Jan 2005 01:26:27 GMT  
 I am having trouble reading a time stamp on a video using OCR
Thank you for your response unfortunately I am unable to send this
image over the net, but the image quality is very poor. the time stamp
has been inserted using an HEI character inserter, and I believe that
it is a very old component, I would appreciate any input as to how I
would be able to enhance the contrast? Excuse my inexperience but I
have just started using labview, so I need all the help I can get

Thank you

Ernest



Sat, 08 Jan 2005 02:47:16 GMT  
 I am having trouble reading a time stamp on a video using OCR
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.

<a
href="http://zone.ni.com/devzone/conceptd.nsf/webmain/E69D110920B99E8386256...">Image
Filtering Overview</a>
<a
href="http://zone.ni.com/devzone/devzone.nsf/webcategories/605B55C3100D0218...">Image
Processing</a>
<a
href="http://zone.ni.com/devzone/devzone.nsf/webcategories/E28E087D201C1AD4...">Optical
Character Recognition</a>

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



Sat, 08 Jan 2005 23:14:12 GMT  
 I am having trouble reading a time stamp on a video using OCR
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

Quote:

> 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.

> <a
> href="http://zone.ni.com/devzone/conceptd.nsf/webmain/E69D110920B99E8386256...">Image
> Filtering Overview</a>
> <a
> href="http://zone.ni.com/devzone/devzone.nsf/webcategories/605B55C3100D0218...">Image
> Processing</a>
> <a
> href="http://zone.ni.com/devzone/devzone.nsf/webcategories/E28E087D201C1AD4...">Optical
> Character Recognition</a>

> 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



Mon, 10 Jan 2005 09:29:18 GMT  
 I am having trouble reading a time stamp on a video using OCR
I suggest to post this question at the <a
href="http://exchange.ni.com/servlet/ProcessRequest?RHIVEID=101&RPAGEID=8&R...">Vision</a>
section. There are persons there that dealing with these problems is
like breathing.

Nevertheless, I am pretty sure they will start in a similar fashion.



Mon, 10 Jan 2005 10:03:15 GMT  
 
 [ 6 post ] 

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