Question Loss of quality converting array to image

[pablogvivo]

Hi, I´m trying convert an array to image. This picture is a dot to dot representation and as you can see have more noise but closer to reality

This one is the image create by vb and is more smooth but there is fake yellow line in the left box and the edge of the yellow box is noisy plus the hammer problem.

I stack the code at the end, valor array has a dimension of 500x375. I call first to dibujar subprocess and after that pass the rgb array to byte2image subprocess, hbmp array it´s the bmp header. So If you know what is the problem please help me .

Sorry for my english and thanks

    Public Sub Byte2Image(ByRef NewImage As Image)
        Dim ImageStream As MemoryStream
        ReDim total(rgb.Length + hbmp.Length)
        hbmp.CopyTo(total, 0)
        rgb.CopyTo(total, hbmp.Length - 1)
        Try
            If total.GetUpperBound(0) > 0 Then
                ImageStream = New MemoryStream(total)
                NewImage = Image.FromStream(ImageStream)
            Else
                NewImage = Nothing
            End If
        Catch ex As Exception
            NewImage = Nothing
        End Try

    End Sub
Public Sub dibujar()

        Dim g As Byte = 0
        Dim b As Byte = 0
        Dim r As Byte = 0
        Dim oPen As Pen
        Dim open2 As Pen
        Dim i As Integer
        Dim j As Integer
        Dim valoract As UShort
        Dim valorpos As UShort
        'Escalado para que el valor quede entre 0 y 255
        Const escala = 0.767

        oPen = New Pen(Color.YellowGreen, 1)
        oGrafico.Clear(Color.Black)
        'Como hay 376 valores le dejamos un margen de 30 a cada lado
        j = 0
        For i = 1 To 375
            If valor(veces, i) > Val(txtlimite.Text) Then
                If valor(veces, i) > 2333 And valor(veces, i) < 2666 Then
                    r = 255
                    g = 255 - ((valor(veces, i) - 2333) * escala)
                    b = 0
                ElseIf valor(veces, i) >= 2666 And valor(veces, i) < 3000 Then
                    r = 255 - ((valor(veces, i) - 2666) * escala)
                    g = 0
                    b = 0
                ElseIf valor(veces, i) > 2000 And valor(veces, i) < 2333 Then
                    r = 255
                    b = 255 - ((valor(veces, i) - 2000) * escala)
                    g = 255
                Else
                    r = 0
                    g = 0
                    b = 0

                End If
                open2 = New Pen(Color.FromArgb(255, r, g, b), 1)
                valoract = valor(vglobal.veces, i) / 20
                valorpos = valor(vglobal.veces, i + 1) / 20
                oGrafico.DrawLine(oPen, i + 10, 260 - valoract, i + 11, 260 - valorpos)
                oGrafico2.DrawLine(open2, 50 + vglobal.veces, i + 10, 50 + vglobal.veces, i + 11)
            End If
            rgb(((veces) * 1128) + j) = r                'Guarda la componente red
            rgb(((veces) * 1128) + j + 1) = b            'Guarda la componente blue
            rgb(((veces) * 1128) + j + 2) = g            'Guarda la componente green
            j = j + 3
        Next
    End Sub