# unsharp¶

doc

https://ffmpeg.org/ffmpeg-filters.html#unsharp-1

“unsharp” will do what you expect as the name implied. It means “unsharpen” or “blur”. However, the official document will not tell you anything about “What makes us happy?” as it was about “smb”. Therefore, I can not even tell you anything about “why you should use this and when to use it”. However, since it is easy to use, introductions themselves can be done even with amateurs like me.

BTW, like “smartblur”, it is also a slightly confusing filter which acts as “sharpen” when giving a positive value to “amount” while it is named “unsharp”.

• xxx_msize_[xy]: matrix horizontal/vertical size which must be an odd integer.

• xxx_amount: effect strength. Negative values will blur the input, while positive values will sharpen it

#! /bin/sh
ifn="Grape_Vineyard.mp4"
ifnb="basename \"${ifn}\" .mp4" pref="basename$0 .sh"
#
luma_msize=${luma_msize:-5} luma_amount=${luma_amount:-"-1.5"}
#
ffmpeg -y -i "${ifn}" -filter_complex " [0:v]split[0v1][0v2]; [0v1]crop=900:500:30:580,setsar=1, unsharp=lx=${luma_msize}:ly=${luma_msize}:la=${luma_amount}

,drawbox=c=blue[b];

[0v2][b]overlay=30:580[v]
" -map '[v]' -an "${pref}_${ifnb}.mp4"