On Wed, May 10, 2023 at 2:32 PM Michael Koch <astroelectro...@t-online.de> wrote:
> ffmpeg -f lavfi -i zoneplate=kx2=320:ky2=240,format=gray -frames 1 -y > out.png > > When you draw a line through the center, you have > black - gray - white - gray - white - gray -black > which means the sine wave changes its sign in the center. > That's why zoneplates are normally calculated with cos() function. > See also: https://en.wikipedia.org/wiki/Zone_plate#Continuous_zone_plates I replaced sinf with cosf, and output is same, just different phase. _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-devel To unsubscribe, visit link above, or email ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe".
