From a part of a video to pictures in linux

first install ffmpeg, if not already installed.
In Debian, Ubuntu, and Linux Mint in terminal
sudo apt update
sudo apt install ffmpeg
 

From a part of a video to pictures/images on linux
Videonpätkä kuviksi:

In terminal cd to the video directory (folder)

ffmpeg -ss 01:00 -i inputvideoname.mp4 -t 01:01 outputpicturename%05d.png

When there is enough pictures you can stop by pressing Ctrl C