좌표에서 RGB값 받아오기

[DllImport("user32.dll")]

static extern IntPtr GetDC(IntPtr hWnd);

[DllImport("user32.dll")]

static extern int ReleaseDC(IntPtr hWnd, IntPtr hDC);

[DllImport("gdi32.dll")]

static extern int GetPixel(IntPtr hDC, int x, int y);

//GetPixel()함수 정의, Color객체 반환

static public Color GetPixel(Control control, int x, int y)

{

Color color = Color.Empty;

if (control != null)

{

IntPtr hDC = GetDC(control.Handle);

int colorRef = GetPixel(hDC, x, y);

color = Color.FromArgb(

  (int)(colorRef & 0x000000FF),

  (int)(colorRef & 0x0000FF00) >> 8,

  (int)(colorRef & 0x00FF0000) >> 16);

ReleaseDC(control.Handle, hDC);

}

return color;

}

출처 : http://balthasar.tistory.com/10