function UploadPNG() {
// We should only read the screen after all rendering is complete
yield WaitForEndOfFrame();
// Create a texture the size of the screen, RGB24 format
var width = Screen.width;
var height = Screen.height;
var tex = new Texture2D( width, height, TextureFormat.RGB24, false );
// Read screen contents into the texture
tex.ReadPixels( Rect(0, 0, width, height), 0, 0 );
tex.Apply();
// Encode texture into PNG
var bytes = tex.EncodeToPNG();
Destroy( tex );
}