BlobCounter - support for white background

[Google Code Exporter]

Currently as i've understood BlobCounter supports only BG colors less or equal 
to BackgroundThreshold property. It would be nice to have switch property that 
will enable grater or equal mode.

Currently i've roughly modified lib code to have such behaviour. 

Original issue reported on code.google.com by [e-mail] on 20 Nov 2013 at 6:59

[Google Code Exporter]

It might be easier just to invert an image, rather than making Blob Counter 
slower with extra cases.

Original comment by [e-mail] on 20 Nov 2013 at 8:18

[Google Code Exporter]

Is it can be done using Threshold class? Just found it... Or please can you 
clarify how this can be achieved.

Original comment by [e-mail] on 20 Nov 2013 at 9:37

[Google Code Exporter]

There is another class to invert image. If you check documentation, you will 
find that it is trivial to use. There are no properties, nothing.

Original comment by [e-mail] on 20 Nov 2013 at 9:42

[Google Code Exporter]

Thanks for pointing this! I'll check it.

Original comment by [e-mail] on 20 Nov 2013 at 9:59