问个简单问题
Private Sub 光照效果ToolStripMenuItem_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles 光照效果ToolStripMenuItem.Click '以光照效果显示图像,若按原设计则图片尺寸过大 'Dim MyGraphics As Graphics = Me.PictureBox1.CreateGraphics() 'MyGraphics.Clear(Color.White) 'Dim MyBmp As New Bitmap(Me.PictureBox1.Image,Me.PictureBox1.Width, Me.PictureBox1.Height) 'Dim MyWidth As Integer = MyBmp.Width 'Dim MyHeight As Integer = MyBmp.Height Try Dim MyWidth As Integer = PictureBox1.Image.Width Dim MyHeight As Integer = PictureBox1.Image.Height Dim MyBmp As New Bitmap(Me.PictureBox1.Image, MyWidth, MyHeight) Dim MyImage As Bitmap = MyBmp.Clone(New RectangleF(0, 0, _ MyWidth, MyHeight), System.Drawing.Imaging.PixelFormat.DontCare) 'MyCenter图片中心点，发亮此值会让强光中心发生偏移 Dim MyCenter As New Point(MyWidth / 2, MyHeight / 2) 'Radius强光照射面的半径，即”光晕” Dim Radius As Integer = Math.Min(MyWidth / 2, MyHeight / 2) For i As Integer = MyWidth - 1 To 1 Step -1 For j As Integer = MyHeight - 1 To 1 Step -1 Dim MyLength As Single = CType(Math.Sqrt(Math.Pow((i - _ MyCenter.X), 2) + Math.Pow((j - MyCenter.Y), 2)), Single) '如果像素位于”光晕”之内 If (MyLength < Radius) Then Dim MyColor As Color = MyImage.GetPixel(i, j) Dim r, g, b As Integer '220亮度增加常量，该值越大，光亮度越强 Dim MyPixel As Integer = 220.0F * (1.0F - MyLength / Radius) r = MyColor.R + CType(MyPixel, Integer) r = Math.Max(0, Math.Min(r, 255)) g = MyColor.G + CType(MyPixel, Integer) g = Math.Max(0, Math.Min(g, 255)) b = MyColor.B + CType(MyPixel, Integer) b = Math.Max(0, Math.Min(b, 255)) '将增亮后的像素值回写到位图 Dim MyNewColor As Color = Color.FromArgb(255, r, g, b) MyImage.SetPixel(i, j, MyNewColor) End If Next ' MyGraphics.DrawImage(MyImage, New Rectangle(0, 0, MyWidth, MyHeight)) Next Me.PictureBox1.Image = MyImage Catch ex As Exception MessageBox.Show(ex.Message, "信息提示", _ MessageBoxButtons.OK, MessageBoxIcon.Information) End Try End Sub
