[WinForms] Resize image width/height, keep aspect ratio and replace original image

Private Sub ExtractImages()
    Dim listpath As String = "D:\image folder\image-list\"
    'First line was retrieve blob from mysql database
    Dim mybytearray As Byte() = arr_imagelist.Item(0).arr_image
    Dim name As String = arr_imagelist.Item(0).str_name.ToString.ToLower
    'This line is new name and replacing unwanted character for filename purposes
    Dim newname As String = System.Text.RegularExpressions.Regex.Replace(name.Trim, " ", "_", System.Text.RegularExpressions.RegexOptions.IgnoreCase)
    Dim oFileStream As System.IO.FileStream
    oFileStream = New System.IO.FileStream(listpath & newname & ".png", System.IO.FileMode.Create)
    oFileStream.Write(mybytearray, 0, mybytearray.Length)
    oFileStream.Close()
    'File is send for resize with desired width
    ResizeThis(listpath & name & ".png", 2000, Drawing.Imaging.ImageFormat.Png)
End Sub

Private Sub ResizeThis(ByVal imgpath As String, ByVal maxwidth As Integer, ByVal format As Drawing.Imaging.ImageFormat)
    'This line is use to stream the file to memory in order to overwrite original image. Otherwise, delete file first was another option.
    Dim fs As New FileStream(imgpath, FileMode.Open)
    Dim original As Image = Image.FromStream(fs)
    fs.Close()
    Dim intWidth As Integer = original.Width : Dim intHeight As Integer = original.Height
    Dim newWidth, newHeight As Integer
    If intWidth > maxwidth Then
        newWidth = maxwidth
        newHeight = maxwidth * (intHeight / intWidth)
        File.Delete(imgpath)
        Using ResizedImage As New Bitmap(original, newWidth, newHeight)
            ResizedImage.Save(imgpath, format)
        End Using
    End If
End Sub