Vb.net 图像蒙版使边缘平滑

Question

嘿，我正在尝试使用蒙版使图像看起来漂亮且平滑(抗锯齿)，以便制作圆形图像，如下所示:

原始图像如下所示:

上图的蒙版看起来像这样(红色是要取出的蒙版颜色):

它可以工作，但它给我带来了周围不太好的锯齿状边缘。蒙版是 .png，图像本身也是 .png。

我用来制作面具的代码是这样的:

picNextTopic1.Image = Image.FromStream(wc.OpenRead(anAPI.wallOrgPostImage(keying).Replace("{width}", "50").Replace("{height}", "50"))) 'Download the image from the website.                  
picNextTopic1.Image = ApplyMask(New Bitmap(picNextTopic1.Image), New Bitmap(My.Resources.mask), Color.Red) 'Apply mask to the downloaded image above.

ApplyMask函数是这样的:

Public Function ApplyMask(ByVal bImg As Bitmap, ByVal bMask As Bitmap, ByVal maskColor As Color) As Image
    Dim wImg As Integer = bImg.Width
    Dim hImg As Integer = bImg.Height
    Dim wMask As Integer = bMask.Width
    Dim hMask As Integer = bMask.Height
    Dim intMask As Integer = maskColor.ToArgb
    Dim intTransparent As Integer = Color.Transparent.ToArgb

    Using fpImg As New FastPix(bImg)
        Using fpMask As New FastPix(bMask)
            Dim pixelsImg = fpImg.PixelArray
            Dim pixelsMask = fpMask.PixelArray

            For y As Integer = 0 To Math.Min(hImg, hMask) - 1
                For x As Integer = 0 To Math.Min(wImg, wMask) - 1
                    Dim iImg As Integer = (y * wImg) + x
                    Dim iMask As Integer = (y * wMask) + x

                    If pixelsMask(iMask) = intMask Then
                        pixelsImg(iImg) = intTransparent
                    End If
                Next
            Next
        End Using
    End Using

    Return bImg
End Function

发现使用FastPix here .

任何帮助解决这个问题的帮助都会很棒!谢谢!

更新我拥有的透明表单代码:

Public Sub InitializeMyForm()
    BackColor = Color.Plum
    TransparencyKey = BackColor
End Sub

Answer 1

尝试一下，我确实设法使用TextureBrush以这种方式制作出平滑的图像:

Dim profile As Image = Image.FromFile("c:\...\profile.png")

Protected Overrides Sub OnPaint(e As PaintEventArgs)
  e.Graphics.Clear(Color.SteelBlue)
  e.Graphics.SmoothingMode = SmoothingMode.AntiAlias
  Using tb As New TextureBrush(profile)
    tb.TranslateTransform(120, 64)
    Using p As New GraphicsPath
      p.AddEllipse(120, 64, profile.Width, profile.Width)
      e.Graphics.FillPath(tb, p)
    End Using
  End Using
  MyBase.OnPaint(e)
End Sub

TranslateTransform 和 AddEllipse 位置使用相同的点信息，以便适本地将纹理画笔“居中”。

结果: