Imports System

Imports System.IO

Imports System.IO.Compression

Public Module Module1

    Public Sub Main()

        Const data = "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"

        Dim jpeg1 = Convert.FromBase64String(data)

​

        Dim rnd = New Random()

        Dim jpeg2(1024) As Byte

        rnd.NextBytes(jpeg2)

​

​

        Console.WriteLine($"Worth compressing '{NameOf(jpeg1)}' file: {CompressionRate(jpeg1) <= 95}")

        Console.WriteLine($"Worth compressing '{NameOf(jpeg2)}' file: {CompressionRate(jpeg2) <= 95}")

    End Sub

    Private Function CompressionRate(jpeg As Byte()) As Double

        Using ms As New MemoryStream()

            Using zls As New ZLibStream(ms, CompressionLevel.SmallestSize, True)

                zls.Write(jpeg)

            End Using

            Return ms.Position / jpeg.Length * 100

        End Using

End Function

End Module