title: ESC POS print PNG image
body: <p>I am very new to ESC POS programming on Objective C.
  I have tested the printer with normal ESC pos line command and it works perfectly.
  But I was unable to understand the raster mode command. (GS v 0)</p>
  
  <p>What I simply need is print the PNG receipt using ESC POS (I am creating the receipt as a PNG file) - Generic ESC POS (not STAR or EPSON)
  I tried to search about this command and spec is unclear.</p>