[MPlayer-dev-eng] [CFTWWI] VF logodetect/logoremove

[Ivo]

On Friday 12 August 2005 00:48, Shachar Raindel wrote:
> Another good way to speed-up the code is to reduce the size of the
> area we are applying this filter to - a nice box about 30 pixels away
> from the logo will do the trick, and will usually give huge speed-up -
> we reduce the size of the problem by a factor of about 50, gaining a
> huge speed-up, almost for free (we are now risking creating an ugly
> contour on or bounding box edge, but this can be solved by slowly
> blending from the filtered area to the non-filtered one, and/or
> adjusting the various channels to match the area as much as possible.
>
> I have tested removing a logo, and got great results after about 1000
> iterations, which took about 30 seconds on my PC - P-4 3.0 GHz with 1
> GB of Dual DDR 400 MHz. You can see the result here:
> http://tx.technion.ac.il/~raindel/man_delogo.xcf.bz2 - layered gimp
> picture, which has the original, and the block with the logo after the
> filter. I had to manually adjust the brightness for some weird reason
> - the filter has reduced it in a considerable amount. The results of
> running the filter on a whole screen (also got very nice results after
> about 1000-1500 iterations, but was much slower) are available here:
> http://tx.technion.ac.il/~raindel/whole_screen.png .
>
> Now, get 10 times speed-up from straight-forward optimization, 2 times
> optimizations by using the predicted image as the initial condition
> for the next impainting, and 2 times speed-up by using a dual-core
> system, and you got a nice 1.5fps rate for ultra high quality logo
> removal. Now, is this algorithm usable for removing logos?

I looked at your sample and it looks good. But on the area you chose, almost 
every logo removal algorithm looks good. I did the same test with an 
episode of the Late Show, having the CBS logo in front of Dave's hand, part 
of the desk, part of a piece of paper on that desk and part of the 
background. The result was just as horribly blurred as all other logo 
removal filters I have seen (stretched hand, stretched piece of paper). 
Which is understandible, because the information simply isn't there! This 
might be acceptable for still images, but once it starts moving, it's 
really annoying IMHO.

--Ivo