Save multiple images to database. Write exception for empty picture boxes - vb.net

Question

I have 4 picture boxes on my form that I use to store images and send to my database: I do it through a table adapter. The images are converted to a stream through this Function:
Public Function ConvertImage(ByVal myImage As Image) As Byte()
'store image in memory before converting and
'create memory stream, save image in proper format
Dim mStream As New MemoryStream
myImage.Save(mStream, System.Drawing.Imaging.ImageFormat.Jpeg)
'convert new stream into bytes and indicate size
Dim myBytes(mStream.Length - 1) As Byte
mStream.Position = 0
mStream.Read(myBytes, 0, mStream.Length)
Return myBytes
End Function
The problem I have is when one or more of my picture boxes have no images, how do I indicate on procedure if one or more picture boxes are empty, then set the image to Nothing. Here is a shorten version of my procedure as it is now
Private Sub btnSaveCategory_Click(sender As Object, e As EventArgs) Handles btnSaveCategory.Click
Dim picImage As Image = picBox1.Image
Dim picImage 2 As Image = picBox2.Image
Dim picImage 3 As Image = picBox3.Image
Dim picImage 4 As Image = picBox4.Image
PRODUCT_CATEGORYTableAdapter.InsertNewCategory(txtCategoryName.Text, ConvertImage(picImage),Image(picImage2), Image(picImage3), Image(picImage4))
End Sub
How can I check for an empty picture box and set it to empty so my procedure does not error out because an image does not exist on one or more boxes?
Thank you.

Answer 1

Try this
If pictureBox.Image is Nothing Then
//do stuff here
End If