Question: I have a stupid question:

I have a black circle on white background, something like:

![enter image description here](https://i.stack.imgur.com/DQLPv.gif)

I have a code in Matlab that gets an image with a black circle and returns the number of pixels in the circle.

**will I get the same number of pixels in a camera of 5 mega pixel and a camera of 8 mega pixel?**

Answer: 
Add Event to toolstrip and set OwnerDraw to true: 

```
public Form1() {
     InitializeComponent();
     toolTip1.OwnerDraw = true;
     toolTip1.Draw += new DrawToolTipEventHandler(toolTip1_Draw);          
 }

```

Then do add a method for Draw Event:

```
void toolTip1_Draw(object sender, DrawToolTipEventArgs e) {
     Font f = new Font("Arial", 10.0f);
     toolTip1.BackColor = System.Drawing.Color.Red;
     e.DrawBackground();
     e.DrawBorder();
     e.Graphics.DrawString(e.ToolTipText, f, Brushes.Black, new PointF(2, 2));
 }

```
When you set a Control to OwnerDraw, you have to handle the drawing of the control yourself.

Here's a quick and dirty example (adapt to your taste):

```
Private Sub ToolTip1_Draw(sender As Object, e As DrawToolTipEventArgs) Handles ToolTip1.Draw
    Dim tt As ToolTip = CType(sender, ToolTip)
    Dim b As Brush = New SolidBrush(tt.BackColor)

    e.Graphics.FillRectangle(b, e.Bounds)

    Dim sf As StringFormat = New StringFormat
    sf.Alignment = StringAlignment.Center
    sf.LineAlignment = StringAlignment.Center
    e.Graphics.DrawString(e.ToolTipText, SystemFonts.DefaultFont, SystemBrushes.ActiveCaptionText, e.Bounds, sf)

    sf.Dispose()
    b.Dispose()
End Sub

```

Cheers