oxipng — oxipng.exe -o 2 --libdeflater --threads 1 --alpha --strip all

file insize instate stats outsize outstate savings
chart1.png 321684 bytes /c2 /f4 /n32
Kernel  Time =     0.015 =    2%
User    Time =     0.687 =   97%
Process Time =     0.703 =   99%    Virtual  Memory =     16 MB
Global  Time =     0.703 =  100%    Physical Memory =     13 MB
250626 bytes /c2 /f0 /n51 71058 bytes
chart2.png 574423 bytes /c2 /f4 /n23
Kernel  Time =     0.000 =    0%
User    Time =     0.937 =  100%
Process Time =     0.937 =  100%    Virtual  Memory =     18 MB
Global  Time =     0.933 =  100%    Physical Memory =     19 MB
505330 bytes /c2 /f5 /n63 69093 bytes
chart3.png 517620 bytes /c2 /f4 /n28
Kernel  Time =     0.000 =    0%
User    Time =     0.765 =   96%
Process Time =     0.765 =   96%    Virtual  Memory =     17 MB
Global  Time =     0.790 =  100%    Physical Memory =     14 MB
440749 bytes /c2 /f0 /n77 76871 bytes
chart4.png 136899 bytes /c2 /f4 /n10
Kernel  Time =     0.031 =    5%
User    Time =     0.562 =   96%
Process Time =     0.593 =  102%    Virtual  Memory =     14 MB
Global  Time =     0.581 =  100%    Physical Memory =     14 MB
124663 bytes /c2 /f5 /n11 12236 bytes
chart5.png 758590 bytes /c2 /f4 /n22
Kernel  Time =     0.015 =    1%
User    Time =     0.890 =   97%
Process Time =     0.906 =   99%    Virtual  Memory =     19 MB
Global  Time =     0.912 =  100%    Physical Memory =     15 MB
555861 bytes /c2 /f0 /n108 202729 bytes
chart6.png 309145 bytes /c2 /f4 /n25
Kernel  Time =     0.046 =    8%
User    Time =     0.515 =   92%
Process Time =     0.562 =  100%    Virtual  Memory =     14 MB
Global  Time =     0.559 =  100%    Physical Memory =     17 MB
261863 bytes /c2 /f0 /n19 47282 bytes
chart7.png 590400 bytes /c2 /f4 /n16
Kernel  Time =     0.031 =    2%
User    Time =     1.062 =  100%
Process Time =     1.093 =  103%    Virtual  Memory =     18 MB
Global  Time =     1.052 =  100%    Physical Memory =     17 MB
467813 bytes /c2 /f0 /n29 122587 bytes
chart8.png 155980 bytes /c2 /f4 /n8
Kernel  Time =     0.000 =    0%
User    Time =     0.609 =   97%
Process Time =     0.609 =   97%    Virtual  Memory =     15 MB
Global  Time =     0.625 =  100%    Physical Memory =     14 MB
122232 bytes /c2 /f0 /n19 33748 bytes
total savings 635604 bytes
total time 6,16 seconds