/var/www/img.caricoos.org/public_html/VIIRS/afai/merge/20200891612.png
/usr/bin/optipng -o2 


array(9) {
  [0]=>
  string(38) "OptiPNG 0.6.4: Advanced PNG optimizer."
  [1]=>
  string(37) "Copyright (C) 2001-2010 Cosmin Truta."
  [2]=>
  string(0) ""
  [3]=>
  string(85) "** Processing: /var/www/img.caricoos.org/public_html/VIIRS/afai/merge/20200891612.png"
  [4]=>
  string(32) "Error: Can't open the input file"
  [5]=>
  string(0) ""
  [6]=>
  string(16) "** Status report"
  [7]=>
  string(30) "1 file(s) have been processed."
  [8]=>
  string(33) "1 error(s) have been encountered."
}