Main idea: create a color map to see which point the user clicked on.
To create this color map, start with the original map, overlay it on a blank bitmap and write a small tool application to help you:
MouseClick PictureBox,- ( ) ,
GetPixel , ,- .
ARGB 3 ; , - .
1f * PictureBox.clientSize.Width / PictureBox.Image.Width.
PictureBox.MouseMove , , mouse cursor betwenn Hand Default , , .. .
, PNG, JPG!
, ( ) Place Dictionary<Color, Place> Place Color..