طريقة تحويل الصور الملونه الي صور ابيض واسود

كود :
Public Class Form1



Private Sub btnOpenColorImage_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnOpenColorImage.Click



Dim dlg As OpenFileDialog = New OpenFileDialog()

Dim imagFilter As String = "Image files (*.jpg,*.jpeg,*.bmp,*.gif,*.png)|*.BMP;*.PNG;*.JPG;*.JPEG;*.GIF"



dlg.Filter = imagFilter



dlg.RestoreDirectory = True





If dlg.ShowDialog() = DialogResult.OK Then

Dim img As Image = Image.FromFile(dlg.FileName)



PictureBox1.Image = img.GetThumbnailImage(PictureBox1.Width, PictureBox1.Height, Nothing, Nothing)





End If

End Sub



Private Sub btnConvertToGray_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnConvertToGray.Click



If PictureBox1.Image Is Nothing Then

Dim msgString As String = "Load the Colored Image"

Dim msgCaption As String = "Error"



MessageBox.Show(msgString, msgCaption, MessageBoxButtons.OK, MessageBoxIcon.Warning)



Else

Dim grayImage As Image = PictureBox1.Image

Dim bm As Bitmap = New Bitmap(grayImage.Width, grayImage.Height)

Dim g As Graphics = Graphics.FromImage(bm)

Dim cm As System.Drawing.Imaging.ColorMatrix = New System.Drawing.Imaging.ColorMatrix(New Single()() _

{New Single() {0.3, 0.3, 0.3, 0, 0}, _

New Single() {0.59, 0.59, 0.59, 0, 0}, _

New Single() {0.11, 0.11, 0.11, 0, 0}, _

New Single() {0, 0, 0, 1, 0}, _

New Single() {0, 0, 0, 0, 1}})



Dim ia As System.Drawing.Imaging.ImageAttributes = New System.Drawing.Imaging.ImageAttributes()

ia.SetColorMatrix(cm)

g.DrawImage(grayImage, New Rectangle(0, 0, grayImage.Width, _

grayImage.Height), 0, 0, grayImage.Width, _

grayImage.Height, GraphicsUnit.Pixel, ia)

g.Dispose()

PictureBox2.Image = bm.GetThumbnailImage(PictureBox2.Width, PictureBox2.Height, Nothing, Nothing)



End If



End Sub



Private Sub btnSaveGrayImage_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnSaveGrayImage.Click



Dim SaveFileDialog1 As New SaveFileDialog()

SaveFileDialog1.Filter = "Image files (*.BMP, *.JPG, *.GIF)|*.bmp;*.jpg;*.gif"



If SaveFileDialog1.ShowDialog() = DialogResult.OK Then

If Not PictureBox1.Image Is Nothing Then

PictureBox2.Image.Save(SaveFileDialog1.FileName)

End If



End If

End Sub



End Class