title: How to open and modify png in C++
body: <p>How to, display png (generally images beside .bmp) get it's depth, color(r,g,b) of a particular pixels(x,y) and how to change exactly one pixel then save the image. I could not find any simple example of that. Please show any sample</p>
  
  <p><strong>No 3rd party libraries, any please.</strong></p>