Convert png to raw Online: png2raw
You can use Tom's Editor to easily convert images from
Portable Network Graphics .PNG to RAW Dump
Tom's Editor is a free, online image manipulation and converter program.
Go to Tom's Editor
Portable Network Graphics is an image format with extension PNG.
This is just raw pixels saved in a file. Format used mostly by old games. RAW files do not have any header so if you don't know what is the original width and height of the image it might be hard to decode them.