myPC:~ yama$ ssh 1234567890@ssh02.ecc.u-tokyo.ac.jp
Last login: Fri May 14 08:11:14 2021 from 111.101.139.33
ssh02:~ 1234567890$ cd Desktop
ssh02:Desktop 1234567890$ mkdir practice
ssh02:Desktop 1234567890$ cd practice
ssh02:practice 1234567890$ ls -l
ssh02:practice 1234567890$ 


ssh02:practice 1234567890$ ls -l
total 1705
-rw-r--r--  1 1234567890  student  872744  5 14 13:33 image01.jpg
ssh02:practice 1234567890$ convert image01.jpg image01.png
ssh02:practice 1234567890$ ls -l
total 4524
-rw-r--r--  1 1234567890  student   872744  5 14 13:33 image01.jpg
-rw-r--r--  1 1234567890  student  1443287  5 14 13:33 image01.png
ssh02:practice 1234567890$ 


ssh02:practice 1234567890$ convert image01.jpg image01.gif
ssh02:practice 1234567890$ ls -l
total 5849
-rw-r--r--  1 1234567890  student   678181  5 14 13:36 image01.gif
-rw-r--r--  1 1234567890  student   872744  5 14 13:33 image01.jpg
-rw-r--r--  1 1234567890  student  1443287  5 14 13:33 image01.png
ssh02:practice 1234567890$ 



ssh02:practice 1234567890$ convert -quality 10 image01.jpg image01_q10.jpg
ssh02:practice 1234567890$ ls -l
total 5904
-rw-r--r--  1 1234567890  student   678181  5 14 13:36 image01.gif
-rw-r--r--  1 1234567890  student   872744  5 14 13:33 image01.jpg
-rw-r--r--  1 1234567890  student  1443287  5 14 13:33 image01.png
-rw-r--r--  1 1234567890  student    27684  5 14 13:40 image01_q10.jpg
ssh02:practice 1234567890$ 


ssh02:practice 1234567890$ convert -quality 50 image01.jpg image01_q50.jpg
ssh02:practice 1234567890$ ls -l
total 6080
-rw-r--r--  1 1234567890  student   678181  5 14 13:36 image01.gif
-rw-r--r--  1 1234567890  student   872744  5 14 13:33 image01.jpg
-rw-r--r--  1 1234567890  student  1443287  5 14 13:33 image01.png
-rw-r--r--  1 1234567890  student    27684  5 14 13:40 image01_q10.jpg
-rw-r--r--  1 1234567890  student    89754  5 14 13:42 image01_q50.jpg
ssh02:practice 1234567890$ 


ssh02:practice 1234567890$ convert -quality 50 image01.png image01_q50.png
ssh02:practice 1234567890$ ls -l
total 8899
-rw-r--r--  1 1234567890  student   678181  5 14 13:36 image01.gif
-rw-r--r--  1 1234567890  student   872744  5 14 13:33 image01.jpg
-rw-r--r--  1 1234567890  student  1443287  5 14 13:33 image01.png
-rw-r--r--  1 1234567890  student    27684  5 14 13:40 image01_q10.jpg
-rw-r--r--  1 1234567890  student    89754  5 14 13:42 image01_q50.jpg
-rw-r--r--  1 1234567890  student  1443319  5 14 13:42 image01_q50.png
ssh02:practice 1234567890$ 


ssh02:practice 1234567890$ convert -quality 1 image01_q50.jpg image01_q50_q1.jpg
ssh02:practice 1234567890$ convert -quality 90 image01_q50.png image01_q50_q90.png
ssh02:practice 1234567890$ ls -l
total 11738
-rw-r--r--  1 1234567890  student   678181  5 14 13:36 image01.gif
-rw-r--r--  1 1234567890  student   872744  5 14 13:33 image01.jpg
-rw-r--r--  1 1234567890  student  1443287  5 14 13:33 image01.png
-rw-r--r--  1 1234567890  student    27684  5 14 13:40 image01_q10.jpg
-rw-r--r--  1 1234567890  student    89754  5 14 13:42 image01_q50.jpg
-rw-r--r--  1 1234567890  student  1443319  5 14 13:42 image01_q50.png
-rw-r--r--  1 1234567890  student     9861  5 14 13:44 image01_q50_q1.jpg
-rw-r--r--  1 1234567890  student  1443282  5 14 13:44 image01_q50_q90.png
ssh02:practice 1234567890$ 


ssh02:practice 1234567890$ convert -quality 50 image01_q50_q1.jpg image01_q50_q1_q50.jpg
ssh02:practice 1234567890$ convert -quality 50 image01_q50_q90.png image01_q50_q90_q50.png
ssh02:practice 1234567890$ ls -l
total 14588
-rw-r--r--  1 1234567890  student   678181  5 14 13:36 image01.gif
-rw-r--r--  1 1234567890  student   872744  5 14 13:33 image01.jpg
-rw-r--r--  1 1234567890  student  1443287  5 14 13:33 image01.png
-rw-r--r--  1 1234567890  student    27684  5 14 13:40 image01_q10.jpg
-rw-r--r--  1 1234567890  student    89754  5 14 13:42 image01_q50.jpg
-rw-r--r--  1 1234567890  student  1443319  5 14 13:42 image01_q50.png
-rw-r--r--  1 1234567890  student     9861  5 14 13:44 image01_q50_q1.jpg
-rw-r--r--  1 1234567890  student    15510  5 14 13:46 image01_q50_q1_q50.jpg
-rw-r--r--  1 1234567890  student  1443282  5 14 13:44 image01_q50_q90.png
-rw-r--r--  1 1234567890  student  1443319  5 14 13:47 image01_q50_q90_q50.png
ssh02:practice 1234567890$