Dana 17. 10. 2015. 13:29 osoba "Michael Koch" <[email protected]> napisala je: > > Hi all, > > I have some questions about the scaling algorithms in FFmpeg. > https://www.ffmpeg.org/ffmpeg-scaler.html#sws_005fflags > > 1. Which is the default algorithm? > > 2. I have many pictures with resolution 5472x3648, which are combined to make a video with resolution 1800x1200. Any pixel in the video must be calculated from 3x3 pixels in the input pictures. > The input pictures contain stars in the night sky which are slowly moving. Most stars are so small that they are just one pixel. > If I use a "nearest neighbor" algorithm, then the star will blink on-off in the video. > If I use any averaging algorithm, then the contrast will go down because the star is averaged with the dark neighbor pixels. > Which is the best algorithm in this case? I need something like the maximum value out of the 3x3 neighborhood.
That looks like the job for the filter, see inflate, deflate, erosion and dilation filters. > > 3. Please improve the documentation. For example: ‘experimental’ Select experimental scaling algorithm. > Wow, that sounds interesting, but what does it do? > > Thanks, > Michael > > > -- ********************************************** > ASTRO ELECTRONIC Dipl.-Ing. Michael Koch > Raabestr. 43 37412 Herzberg > www.astro-electronic.de > Tel. +49 5521 854265 Fax +49 5521 854266 > ********************************************** > > _______________________________________________ > ffmpeg-user mailing list > [email protected] > http://ffmpeg.org/mailman/listinfo/ffmpeg-user _______________________________________________ ffmpeg-user mailing list [email protected] http://ffmpeg.org/mailman/listinfo/ffmpeg-user
