Visual Basic - Image Processing 4 (greyscale)

Setelah seminggu tidak menulis karena sakit, akhirnya diberi kesempatan kembali untuk menulis lagi, oke pada tutorial sebelumnya kita sudah membuat salah satu sistem dari image processing yaitu cropping, kali ini kita akan membuat sistem greyscale.

Greyscale sendiri adalah warna-warna piksel yang hanya terdiri dari warna hitam dan putih saja.

Belum terlalu mengerti tentang Visual Studio? baca disini, oke langsung saja kita buat enginenya.

Pertama, buat UI (User Interface) pada visual basic menggunakan tools OpenFileDialog, SaveFileDialog, Button, dan PictureBox sehingga tampilannya akan tampak seperti ini,

Selanjutnya, klik dua kali button Open dan ketikkan code berikut,

        OpenFileDialog1.Filter = "image file (*.jpg) |*.jpg| all files (*.*) | *.*"
        If OpenFileDialog1.ShowDialog <> Windows.Forms.DialogResult.Cancel Then
            PictureBox1.Image = Image.FromFile(OpenFileDialog1.FileName)
        End If

Kemudian, klik dua kali button Process dan ketikkan code berikut,

PictureBox1.Image = gray(PictureBox1.Image)

Terakhir, klik dua kali button Save dan ketikkan code berikut,

        Try
            SaveFileDialog1.Filter = "JPEG |*.jpeg"
            If SaveFileDialog1.ShowDialog() = Windows.Forms.DialogResult.OK Then
                PictureBox1.Image.Save(SaveFileDialog1.FileName, System.Drawing.Imaging.ImageFormat.Jpeg)
            End If
        Catch ex As Exception
        End Try

Tambahkan Import dan juga function grey, sehingga fullcodenya akan tampak seperti ini

Imports System.Drawing.Imaging
Public Class Form1

    Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
        OpenFileDialog1.Filter = "image file (*.jpg) |*.jpg| all files (*.*) | *.*"
        If OpenFileDialog1.ShowDialog <> Windows.Forms.DialogResult.Cancel Then
            PictureBox1.Image = Image.FromFile(OpenFileDialog1.FileName)
        End If
    End Sub

    Private Sub Button2_Click(sender As Object, e As EventArgs) Handles Button2.Click
        PictureBox1.Image = gray(PictureBox1.Image)
    End Sub

    Public Function gray(ByVal image As Bitmap) As Bitmap
        Dim a As New Bitmap(image.Width, image.Height)
        Dim b As Graphics = Graphics.FromImage(a)
        Dim c As New ColorMatrix(New Single()() {New Single() {0.3F, 0.3F, 0.3F, 0, 0},
                                                 New Single() {0.59F, 0.59F, 0.59F, 0, 0},
                                                 New Single() {0.11F, 0.11F, 0.11F, 0, 0},
                                                 New Single() {0, 0, 0, 1, 0},
                                                 New Single() {0, 0, 0, 0, 1}})
        Dim d As New ImageAttributes()
        d.SetColorMatrix(c)
        b.DrawImage(image, New Rectangle(0, 0, image.Width, image.Height), 0, 0, image.Width, image.Height, GraphicsUnit.Pixel, d)
        d.Dispose()
        Return a
    End Function

    Private Sub Button3_Click(sender As Object, e As EventArgs) Handles Button3.Click
        Try
            SaveFileDialog1.Filter = "JPEG |*.jpeg"
            If SaveFileDialog1.ShowDialog() = Windows.Forms.DialogResult.OK Then
                PictureBox1.Image.Save(SaveFileDialog1.FileName, System.Drawing.Imaging.ImageFormat.Jpeg)
            End If
        Catch ex As Exception
        End Try
    End Sub
End Class

Dan tampilannya akan tampak seperti ini,

===DONE!===