Ancho y alto BMP, FileStream Ejercicio VB.Net - Curso de Programación Visual Basic

Imports System
Imports System.IO
Public Class exercise188
    Public Shared Sub Main()
        Dim myFile As FileStream
        Dim data As Byte()
        Dim width, height As Integer
        Const SIZE As Integer = 54
        Console.Write("Enter the name of file: ")
        Dim fileName As String = Console.ReadLine()

        If Not File.Exists(fileName) Then
            Console.WriteLine("The file not exists!!!")
            Return
        End If

        Try
            myFile = File.OpenRead(fileName)
            data = New Byte(53) {}
            myFile.Read(data, 0, SIZE)
            myFile.Close()
            Dim b1 As Byte = data(0)
            Dim b2 As Byte = data(1)

            If (Convert.ToChar(b1) <> "B"c) OrElse (Convert.ToChar(b2) <> "M"c) Then
                Console.WriteLine("This File is NOT a BMP file")
                Return
            End If

            width = data(18) + (data(19) * 256) + (data(20) * 256 * 256) + (data(21) * 256 * 256 * 256)
            height = data(22) + (data(23) * 256) + (data(24) * 256 * 256) + (data(25) * 256 * 256 * 256)
            Console.WriteLine("Width: {0} - Heigth: {1}", width, height)
        Catch e As Exception
            Console.WriteLine("Error: {0}!!!", e.message())
        End Try
    End Sub
End Class