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Forum Topic - Image searching within another image: (4 Items)
   
Update
Dinyo Haygarov(deleted)
10/28/2013 7:23 AM
post106298
Image searching within another image   
is it possible to search for a certain image within another bigger image and retrieve it's coordinates within the bigger
 image?
Mate Szarvas
10/28/2013 8:04 AM
post106307
Re: Image searching within another image   
It definitely is possible but QNX does not provide any libraries for that.

Depending on countless factors you may either read in both images using existing API-s and do the search yourself along 
the lines of a 2D strstr or rely on an image recognition library.

If you go with the roll your own solution approach but you hit performance issues then you can subsample both images 
multiple times (using a factor of 2 can be implemented most efficiently) resulting in an image pyramid and do the search
 at higher resolutions only in areas that gave a hit in lower resolutions.

--
Mate

On Oct 28, 2013, at 8:23 PM, Dinyo Haygarov <community-noreply@qnx.com>
 wrote:

> is it possible to search for a certain image within another bigger image and retrieve it's coordinates within the 
bigger image?
> 
> 
> 
> _______________________________________________
> 
> Advanced Graphics
> http://community.qnx.com/sf/go/post106298
> To cancel your subscription to this discussion, please e-mail advanced-graphics-unsubscribe@community.qnx.com
Dinyo Haygarov(deleted)
10/28/2013 9:23 AM
post106308
Re: Image searching within another image   
Can you point me to an existing image recognition library in the NDK which I can use?
Mate Szarvas
10/28/2013 9:49 AM
post106310
Re: Image searching within another image   
Sorry but I cannot.  Not familiar with the NDK and I'd suggest you ask for BlackBerry specific information on the 
BlackBerry forums.

You will have to do your homework but I know that most people's gut reaction when faced with similar problems is to say 
"OpenCV!"  I do not know if it has something that solves your particular problem out of the box.
There appears to be an "Officially sanctioned port of OpenCV to the Blackberry/QNX platform" at the following location: 
https://github.com/blackberry/OpenCV/

If you are after a bit by bit perfect match and don't care about the CPU use then it should be fastest to check how to 
access the frame via the image library and write your own matcher with for(x0 on big image) for(y0 on big image) for(x 
on small image) for(y on small image).
If you need approximate matching, need robustness for scale/rotation/other transformations or just need more efficiency 
then do your research on existing libraries.

--
Mate



On Oct 28, 2013, at 10:23 PM, Dinyo Haygarov <community-noreply@qnx.com<mailto:community-noreply@qnx.com>>;
 wrote:

Can you point me to an existing image recognition library in the NDK which I can use?



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