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

file insize instate stats outsize outstate savings
lorem.png 135614 bytes /c2 /f0 /n63
Kernel  Time =     0.000 =    0%
User    Time =     0.750 =   99%
Process Time =     0.750 =   99%    Virtual  Memory =     16 MB
Global  Time =     0.754 =  100%    Physical Memory =     15 MB
105679 bytes /c2 /f0 /n16 29935 bytes
lorem_90.png 483089 bytes /c2 /f0 /n106
Kernel  Time =     0.031 =    5%
User    Time =     0.546 =   93%
Process Time =     0.578 =   99%    Virtual  Memory =     17 MB
Global  Time =     0.583 =  100%    Physical Memory =     13 MB
451970 bytes /c2 /f0 /n56 31119 bytes
lorem_big.png 127451 bytes /c2 /f0 /n3
Kernel  Time =     0.031 =    3%
User    Time =     0.875 =  103%
Process Time =     0.906 =  107%    Virtual  Memory =     17 MB
Global  Time =     0.844 =  100%    Physical Memory =     14 MB
68797 bytes /c0 /f0 /d8 /n26 58654 bytes
lorem_big_16.png 65084 bytes /c0 /f0 /d8 /n28
Kernel  Time =     0.000 =    0%
User    Time =     0.734 =  102%
Process Time =     0.734 =  102%    Virtual  Memory =     15 MB
Global  Time =     0.716 =  100%    Physical Memory =     15 MB
46626 bytes /c0 /f0 /d8 /n12 18458 bytes
lorem_big_17.png 65551 bytes /c0 /f0 /d8 /n35
Kernel  Time =     0.000 =    0%
User    Time =     0.765 =  104%
Process Time =     0.765 =  104%    Virtual  Memory =     15 MB
Global  Time =     0.729 =  100%    Physical Memory =     15 MB
45954 bytes /c0 /f0 /d8 /n13 19597 bytes
lorem_big_noise.png 823706 bytes /c2 /f0 /n82
Kernel  Time =     0.031 =    1%
User    Time =     3.093 =   99%
Process Time =     3.125 =  100%    Virtual  Memory =     24 MB
Global  Time =     3.124 =  100%    Physical Memory =     23 MB
613790 bytes /c2 /f0 /n59 209916 bytes
lorem_gray.png 140439 bytes /c2 /f0 /n123
Kernel  Time =     0.000 =    0%
User    Time =     0.484 =  107%
Process Time =     0.484 =  107%    Virtual  Memory =     14 MB
Global  Time =     0.449 =  100%    Physical Memory =     13 MB
56668 bytes /c0 /f0 /d8 /n6 83771 bytes
lorem_image.png 133069 bytes /c2 /f0 /n3
Kernel  Time =     0.000 =    0%
User    Time =     1.171 =  103%
Process Time =     1.171 =  103%    Virtual  Memory =     21 MB
Global  Time =     1.136 =  100%    Physical Memory =     19 MB
117411 bytes /c2 /f0 /n33 15658 bytes
lorem_noise.png 542244 bytes /c2 /f0 /n67
Kernel  Time =     0.000 =    0%
User    Time =     1.515 =   98%
Process Time =     1.515 =   98%    Virtual  Memory =     18 MB
Global  Time =     1.545 =  100%    Physical Memory =     15 MB
428159 bytes /c2 /f0 /n84 114085 bytes
lorem_pal.png 121950 bytes /c2 /f0 /n73
Kernel  Time =     0.000 =    0%
User    Time =     0.500 =  111%
Process Time =     0.500 =  111%    Virtual  Memory =     14 MB
Global  Time =     0.449 =  100%    Physical Memory =     13 MB
51835 bytes /c0 /f0 /d8 /n6 70115 bytes
total savings 651308 bytes
total time 10,33 seconds