.NET 4.x Процедура для изменения прозрачности картинки - Visual Basic .NET

Формулировка задачи:

Процедура для изменения прозрачности - VB.net

Private Sub prozr(ByVal sen As PictureBox, ByVal pr As Integer)
        Dim OPA As Double = pr / 100
        Dim img As Image = sen.Image
        Dim copy As Bitmap = New Bitmap(img.Width, img.Height)
        Dim ia As ImageAttributes = New ImageAttributes
        Dim cm As ColorMatrix = New ColorMatrix(New Single()() {New Single() {1, 0, 0, 0, 0}, New Single() {0, 1, 0, 0, 0}, New Single() {0, 0, 1, 0, 0}, New Single() {0, 0, 0, OPA, 0}, New Single() {0, 0, 0, 0, 1}})
        ia.SetColorMatrix(cm)
        Dim g As Graphics
        g = Graphics.FromImage(copy)
        g.DrawImage(img, New Rectangle(0, 0, img.Width, img.Height), 0, 0, img.Width, img.Height, GraphicsUnit.Pixel, ia)
        sen.Image = copy
        g.Dispose()
        img.Dispose()
    End Sub

Источник

- Занимательное программирование на Visual Basic .NET А.Климов

Решение задачи: «.NET 4.x Процедура для изменения прозрачности картинки»

textual
                            Листинг программы 
                        

                            PictureBox2.Image = setTransparentBetween(bb, Color.FromArgb(0, 10, 10), Color.FromArgb(155, 50, 50))
'…
Private Function setTransparentBetween(ByVal img As Bitmap, ByVal cLow As Color, ByVal cHigh As Color) As Bitmap
    Dim copy As Bitmap = New Bitmap(img.Width, img.Height)
    Dim ia As ImageAttributes = New ImageAttributes
    ia.SetColorKey(cLow, cHigh, ColorAdjustType.Bitmap)
    Dim g As Graphics = Graphics.FromImage(copy)
    g.DrawImage(img, New Rectangle(0, 0, img.Width, img.Height), 0, 0, img.Width, img.Height, GraphicsUnit.Pixel, ia)
    g.Dispose()
    img.Dispose()
    Return copy
End Function
                        