[MPlayer-dev-eng] Re: New remove-logo filter

[D Richard Felker III]

On Fri, Feb 25, 2005 at 08:43:24PM +0100, Reimar Döffinger wrote:
> Hi,
> On Fri, Feb 25, 2005 at 10:08:17AM -0800, Trent Piepho wrote:
> > On Fri, 25 Feb 2005, Reimar Döffinger wrote:
> > > Look at my pgm-loading code in this thread, it can be use with almost
> > > zero modification for RGB ppm images, and it's less than 50 lines of pur
> > 
> > But the deblendlogo filter uses an alpha channel, and ppm images don't support
> > alpha.
> 
> ppm for color + pgm for alpha. And yes, it is possible to create this
> with gimp (or in the worst case with tifftopnm), the other way round
> seems a bt more complicated.
> Also it is even more obvious how you can use the mask for the one for
> the other *g*.
> A separate alpha image might be better for the delogo filter speedwise,
> when most of the image doesn't contain the image - alpha only has a
> better chance to fit in cache.

after loading the logo, the filters can find a bounding box for it and
copy it to a smaller buffer with minimal stride. just make sure it
stays 8-byte aligned for vector optimizations, though, when they're
added in the future.

rich