لتحويل صورة ملونة إلى مستوى الرمادي باستخدام مصفوفة التحويل

كود :
Public Class frmMain

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

Dim OpenFileDialog As OpenFileDialog = New OpenFileDialog()

Dim imagFilter As String = "Fichiers d'images (*.jpg,*.jpeg,*.bmp,*.gif,*.png)|*.BMP;*.PNG;*.JPG;*.JPEG;*.GIF"

OpenFileDialog.Filter = imagFilter

OpenFileDialog.RestoreDirectory = True

If OpenFileDialog.ShowDialog() = DialogResult.OK Then

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

pbxColoredImage.Image = img.GetThumbnailImage(pbxColoredImage.Width, pbxColoredImage.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 pbxColoredImage.Image Is Nothing Then

Dim msgString As String = "Veuillez ouvrir un fichier d'image d'abord svp"

Dim msgCaption As String = "Erreur"

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

Else

Dim grayImage As Image = pbxColoredImage.Image

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

Dim g As Graphics = Graphics.FromImage(bm)

'Creation de la matrice contenant les poids de conversion

'0.3 -> Poid du constituant R (Rouge)de la couleur des pixels

'0.59 -> Poid du constituant G (Vert)

'0.11 -> Poid du constituant B (Bleu)

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()

pbxGrayScaleImage.Image = bm.GetThumbnailImage(pbxGrayScaleImage.Width, pbxGrayScaleImage.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 SaveFileDialog As New SaveFileDialog()

SaveFileDialog.Filter = "Fichiers d'images (*.BMP, *.JPG, *.GIF)|*.bmp;*.jpg;*.gif"

If SaveFileDialog.ShowDialog() = DialogResult.OK Then

If Not pbxColoredImage.Image Is Nothing Then

pbxGrayScaleImage.Image.Save(SaveFileDialog.FileName)

End If

End If

End Sub

End Class