Поставить цифры на изображение формата .jpg

    Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
        Dim MyText As String = "Текст который накладываем на избражение"
        Dim MyNewFont As New Font("Arial", 12, FontStyle.Bold) 'задаем параметры для шрифта
        Dim MyNewBrush As New SolidBrush(Color.FromArgb(250, 250, 0, 0)) 'создаем кисть с цветом
        MyNewBrush.Color = Color.FromArgb(250, 250, 0, 0) 'выбираем цвет кисти
        PictureBox1.CreateGraphics.DrawString(MyText, MyNewFont, MyNewBrush, 10, 10) '10 и 20 это отступы от края. 10, это отступ слева, 20 это отступ сверху
    End Sub

Dim visotaKartinki As Integer = bm.Height.ToString
Dim shirinaKartinki As Integer = bm.Weight.ToString

Dim fontSize as String = visotaKartinki * shirinaKartinki / 10

Dim fontSize as String = visotaKartinki * shirinaKartinki / 10

Private Sub Button3_Click(sender As System.Object, e As System.EventArgs) Handles Button3.Click
    Dim dir As New DirectoryInfo("C:\00") 'папка с картинками
    Dim rez As DirectoryInfo = Directory.CreateDirectory("C:\00\rez") 'папка с обработанными картинками
    Dim fStyle As FontStyle = FontStyle.Bold
    Dim fnt As New Font("Arial", 12, fStyle)
    Dim fnt2 As Font
    Dim pnt As New PointF(20, 20) 'левый верхний угол
    Dim jgpEncoder As ImageCodecInfo = GetEncoder(ImageFormat.Jpeg)
    Dim myEncoder As System.Drawing.Imaging.Encoder = System.Drawing.Imaging.Encoder.Quality
    Dim myEncoderParameters As New EncoderParameters(1)
    Dim myEncoderParameter As New EncoderParameter(myEncoder, 100&)
    myEncoderParameters.Param(0) = myEncoderParameter
    Dim g As Graphics
    Dim str As String = ""
    Dim im As Image
    Dim sz As SizeF
    Dim cl As Color
    Dim br As Brush
    For Each fl As FileInfo In dir.GetFiles("*.jpg")
        str = Path.GetFileNameWithoutExtension(fl.FullName)
        im = Image.FromFile(fl.FullName)
        g = Graphics.FromImage(im)
        sz = g.MeasureString(str, fnt, 100)
        'определяем размер шрифта такой чтобы строка str занимала 15% от ширины картинки
        fnt2 = findFont(0.15, str, fnt, fStyle, im.GetBounds(GraphicsUnit.Pixel).Width, sz.Width)
        'определяем новый цвет как дополнение от фона (примерно)
        cl = findColor(sz, pnt, im)
        br = New SolidBrush(cl)
        g.DrawString(str, fnt2, br, pnt)
        'записываем новую картинку
        im.Save(rez.FullName & "\" & str & ".jpg", jgpEncoder, myEncoderParameters)
    Next
    MsgBox("Ok!")
End Sub
 
''' <param name="prc">перекрытие текста в процентах от ширины картинки</param>
Private Function findFont(ByVal prc As Single, ByVal str As String, ByVal fn As Font, ByVal stl As FontStyle, ByVal w As Single, wt As Single) As Font
    Dim dd, fs As Single
    dd = wt / w
    fs = Int(fn.Size * (prc / dd))
    Return New Font(fn.FontFamily, fs, stl)
End Function
 
Private Function findColor(ByVal sz As SizeF, ByVal p As PointF, ByRef im As Image) As Color
    Dim bm As New Bitmap(im)
    Dim cc1 As Color
    Dim rr, gg, bb, n As Integer
    For i = p.Y To p.Y + sz.Height - 1
        For j = p.X To p.X + sz.Width - 1
            cc1 = bm.GetPixel(j, i)
            rr += cc1.R
            gg += cc1.G
            bb += cc1.B
            n += 1
        Next
    Next
    cc1 = Color.FromArgb(255 - CInt(rr / n), 255 - CInt(gg / n), 255 - CInt(bb / n))
    Return cc1
End Function

Dim br As Brush
Dim sourceRectangle As New Rectangle(20, 20, 100, 30)
  If CopyBitmap(im, sourceRectangle).GetPixel(0, 0).GetBrightness < 0.5 Then
    br = Brushes.White
  Else
    br = Brushes.Black
  End If
g.DrawString(str, fnt, br, pnt)

    Private Function CopyBitmap(source As Bitmap, rect As Rectangle) As Bitmap
        Dim bmp As New Bitmap(1, 1)
        Using g As Graphics = Graphics.FromImage(bmp)
            g.DrawImage(source, 0, 0, rect, GraphicsUnit.Pixel)
        End Using
        Return bmp
    End Function

Imports System.Drawing.Drawing2D
 
Public Class Form1
 
    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        Me.Size = New Size(500, 100)
    End Sub
 
    Private Sub Form1_Paint(ByVal sender As System.Object, ByVal e As System.Windows.Forms.PaintEventArgs) Handles MyBase.Paint
        Dim path As New GraphicsPath
        path.AddString("Test Test Test", _
                       Me.Font.FontFamily, _
                       Me.Font.Style, _
                       48, _
                       Me.ClientRectangle, _
                       New StringFormat With {.Alignment = StringAlignment.Center})
 
        With e.Graphics
            .Clear(Color.White)
            .FillRectangle(New SolidBrush(Color.Black), _
                           New Rectangle(Me.ClientRectangle.Width \ 2, Me.ClientRectangle.Y, _
                                         Me.ClientRectangle.Width \ 2, Me.ClientRectangle.Height))
 
            .SmoothingMode = SmoothingMode.HighQuality
            .InterpolationMode = InterpolationMode.HighQualityBicubic
 
            Dim p As New Pen(Color.FromArgb(Me.ForeColor.ToArgb Xor &HFFFFFF), 2)
            p.Alignment = PenAlignment.Center
            .DrawPath(p, path)
            p.Dispose()
 
            .FillPath(New SolidBrush(Me.ForeColor), path)
        End With
 
        path.Dispose()
    End Sub
End Class