Membuat Photo Editor menggunakan visual basic 2008/VB.net (tahap I)
Untuk Membuat Photo Editor menggunakan visual basic 2008/VB.net cukup
rumit, oleh karena itu saya akan membuat tutorialnya bertahap, pada
tahap awal ini saya akan menerangkan bagaimana memembuat brightness dan
contrass pada gambar dengan menggunakan Visual Basic 2008, langkah awal
untuk membuat Brightness dan contrast pada gambar adalah dengan membuat 1
form dan 1 class (masukkan nama filters pada saat membuat class).
Pada Form1 masukkan komponen-komponen dibawah:
- 1 picturebox
- 2 trackbar
- 2 label
- 1 button
- 1 openfiledialog
Letakkan Picturebox dibagian atas, kemudian letakkan button1 dibawah
picturebox untuk mempersingkat tulisan lihat saja gambar dibawah ini:
Kemudian klik 2 kali Class yang berada pada list sebelah kanan (Slutions
Explorer) hapus semua kode dan masukkan kode dibawah ini:
Kemudian Klik 2 kali form1, hapus semua kode yang ada dan masukkan kode dibawah ini:Imports System.Runtime.InteropServices ' The Marshal class is derieved from here
Imports System.Drawing.Imaging ' BitmapData structure from here
Public Class Filters
Shared bmData As BitmapData
Shared ptr As System.IntPtr
Shared Red As Integer, Green As Integer, Blue As Integer
Shared x As Integer, y As Integer
Shared nOffset As Integer
Public Shared Function ContrastFilter(ByVal ContrastValue As Integer, ByRef b As Bitmap) As Bitmap
If b.PixelFormat = PixelFormat.Format8bppIndexed Then
MsgBox("Tidak support dengan gambar value warna 256.", MsgBoxStyle.Critical Or MsgBoxStyle.ApplicationModal, "Error")
Return Nothing
End If
If (ContrastValue < -100 Or ContrastValue > 100) Then Return Nothing
bmData = b.LockBits(New Rectangle(0, 0, b.Width, b.Height), ImageLockMode.ReadWrite, PixelFormat.Format24bppRgb)
ptr = bmData.Scan0
nOffset = bmData.Stride - b.Width * 3
Dim pixel As Double
Dim contrast As Double = (100 + ContrastValue) / 100
contrast *= contrast
For y = 0 To b.Height - 1
For x = 0 To b.Width - 1
Blue = Marshal.ReadByte(ptr, 0)
pixel = Blue / 255
pixel -= 0.5
pixel *= contrast
pixel += 0.5
pixel *= 255
If (pixel < 0) Then pixel = 0
If (pixel > 255) Then pixel = 255
Marshal.WriteByte(ptr, 0, CByte(pixel))
Green = Marshal.ReadByte(ptr, 1)
pixel = Green / 255
pixel -= 0.5
pixel *= contrast
pixel += 0.5
pixel *= 255
If (pixel < 0) Then pixel = 0
If (pixel > 255) Then pixel = 255
Marshal.WriteByte(ptr, 1, CByte(pixel))
Red = Marshal.ReadByte(ptr, 2)
pixel = Red / 255
pixel -= 0.5
pixel *= contrast
pixel += 0.5
pixel *= 255
If (pixel < 0) Then pixel = 0
If (pixel > 255) Then pixel = 255
Marshal.WriteByte(ptr, 2, CByte(pixel))
ptr = IntPtr.op_Explicit(ptr.ToInt32 + 3)
Next
ptr = IntPtr.op_Explicit(ptr.ToInt32 + nOffset)
Next
b.UnlockBits(bmData)
Return b
End Function
Public Shared Function BrightnessFilter(ByVal BrightnessValue As Integer, ByRef b As Bitmap) As Bitmap
If b.PixelFormat = PixelFormat.Format8bppIndexed Then
MsgBox("256 colors bitmap are not supported.", MsgBoxStyle.Critical Or MsgBoxStyle.ApplicationModal, "Error")
Return Nothing
End If
If BrightnessValue = 0 Then Return Nothing
bmData = b.LockBits(New Rectangle(0, 0, b.Width, b.Height), ImageLockMode.ReadWrite, PixelFormat.Format24bppRgb)
ptr = bmData.Scan0
nOffset = bmData.Stride - b.Width * 3
For y = 0 To b.Height - 1
For x = 0 To (b.Width * 3) - 1
Dim bByte As Integer = Marshal.ReadByte(ptr, 0)
bByte += BrightnessValue
If bByte > 255 Then bByte = 255
If bByte < 0 Then bByte = 0
Marshal.WriteByte(ptr, 0, CByte(bByte))
ptr = IntPtr.op_Explicit(ptr.ToInt32 + 1)
Next
ptr = IntPtr.op_Explicit(ptr.ToInt32 + nOffset)
Next
b.UnlockBits(bmData)
Return b
End Function
Public Shared Function Invert(ByRef b As Bitmap) As Bitmap
If b.PixelFormat = PixelFormat.Format8bppIndexed Then
MsgBox("256 colors bitmap are not supported.", MsgBoxStyle.Critical Or MsgBoxStyle.ApplicationModal, "Error")
Return Nothing
End If
bmData = b.LockBits(New Rectangle(0, 0, b.Width, b.Height), ImageLockMode.ReadWrite, PixelFormat.Format24bppRgb)
ptr = bmData.Scan0
nOffset = bmData.Stride - b.Width * 3
For y = 0 To b.Height - 1
For x = 0 To (b.Width * 3) - 1
Marshal.WriteByte(ptr, 0, CByte(255 - Marshal.ReadByte(ptr, 0)))
ptr = IntPtr.op_Explicit(ptr.ToInt32 + 1)
Next
ptr = IntPtr.op_Explicit(ptr.ToInt32 + nOffset)
Next
b.UnlockBits(bmData)
Return b
End Function
Public Shared Function Grayscale(ByRef b As Bitmap) As Bitmap
If b.PixelFormat = PixelFormat.Format8bppIndexed Then
MsgBox("256 colors bitmap are not supported.", MsgBoxStyle.Critical Or MsgBoxStyle.ApplicationModal, "Error")
Return Nothing
End If
bmData = b.LockBits(New Rectangle(0, 0, b.Width, b.Height), ImageLockMode.ReadWrite, PixelFormat.Format24bppRgb)
ptr = bmData.Scan0
nOffset = bmData.Stride - b.Width * 3
Dim bVal As Byte
For y = 0 To b.Height - 1
For x = 0 To b.Width - 1
Blue = Marshal.ReadByte(ptr, 0)
Green = Marshal.ReadByte(ptr, 1)
Red = Marshal.ReadByte(ptr, 2)
bVal = CByte(0.299 * Red + 0.587 * Green + 0.114 * Blue)
Marshal.WriteByte(ptr, 0, bVal)
Marshal.WriteByte(ptr, 1, bVal)
Marshal.WriteByte(ptr, 2, bVal)
ptr = IntPtr.op_Explicit(ptr.ToInt32 + 3)
Next
ptr = IntPtr.op_Explicit(ptr.ToInt32 + nOffset)
Next
b.UnlockBits(bmData)
Return b
End Function
Public Shared Function AdjustColors(ByRef b As Bitmap, ByVal RedValue As Integer, ByVal BlueValue As Integer, ByVal GreenValue As Integer) As Bitmap
If b.PixelFormat = PixelFormat.Format8bppIndexed Then
MsgBox("256 colors bitmap are not supported.", MsgBoxStyle.Critical Or MsgBoxStyle.ApplicationModal, "Error")
Return Nothing
End If
bmData = b.LockBits(New Rectangle(0, 0, b.Width, b.Height), ImageLockMode.ReadWrite, PixelFormat.Format24bppRgb)
ptr = bmData.Scan0
Dim bVal As Byte
nOffset = bmData.Stride - b.Width * 3
For y = 0 To b.Height - 1
For x = 0 To b.Width - 1
Blue = Marshal.ReadByte(ptr, 0)
Green = Marshal.ReadByte(ptr, 1)
Red = Marshal.ReadByte(ptr, 2)
Red += RedValue
Red = Math.Max(Red, 0)
Red = Math.Min(Red, 255)
Green += GreenValue
Green = Math.Max(Green, 0)
Green = Math.Min(Green, 255)
Blue += BlueValue
Blue = Math.Max(Blue, 0)
Blue = Math.Min(Blue, 255)
Marshal.WriteByte(ptr, 0, CByte(Blue))
Marshal.WriteByte(ptr, 1, CByte(Green))
Marshal.WriteByte(ptr, 2, CByte(Red))
ptr = IntPtr.op_Explicit(ptr.ToInt32 + 3)
Next
ptr = IntPtr.op_Explicit(ptr.ToInt32 + nOffset)
Next
b.UnlockBits(bmData)
Return b
End Function
Public Shared Function AdjustGamma(ByRef b As Bitmap, ByVal RedValue As Double, ByVal GreenValue As Double, ByVal BlueValue As Double) As Bitmap
If b.PixelFormat = PixelFormat.Format8bppIndexed Then
MsgBox("256 colors bitmap are not supported.", MsgBoxStyle.Critical Or MsgBoxStyle.ApplicationModal, "Error")
Return Nothing
End If
If (RedValue < 0.2 Or RedValue > 5) Then Return Nothing
If (GreenValue < 0.2 Or GreenValue > 5) Then Return Nothing
If (BlueValue < 0.2 Or BlueValue > 5) Then Return Nothing
Dim redGamma(256) As Byte
Dim greenGamma(256) As Byte
Dim blueGamma(256) As Byte
Dim i As Integer
For i = 0 To 255
redGamma(i) = CByte(Math.Min(255, CInt(((255.0 * Math.Pow(i / 255.0, 1.0 / RedValue)) + 0.5))))
greenGamma(i) = CByte(Math.Min(255, CInt(((255.0 * Math.Pow(i / 255.0, 1.0 / GreenValue)) + 0.5))))
blueGamma(i) = CByte(Math.Min(255, CInt(((255.0 * Math.Pow(i / 255.0, 1.0 / BlueValue)) + 0.5))))
Next
bmData = b.LockBits(New Rectangle(0, 0, b.Width, b.Height), ImageLockMode.ReadWrite, PixelFormat.Format24bppRgb)
ptr = bmData.Scan0
nOffset = bmData.Stride - b.Width * 3
For y = 0 To b.Height - 1
For x = 0 To b.Width - 1
Marshal.WriteByte(ptr, 0, blueGamma(Marshal.ReadByte(ptr, 0)))
Marshal.WriteByte(ptr, 1, greenGamma(Marshal.ReadByte(ptr, 1)))
Marshal.WriteByte(ptr, 2, redGamma(Marshal.ReadByte(ptr, 2)))
ptr = IntPtr.op_Explicit(ptr.ToInt32 + 3)
Next
ptr = IntPtr.op_Explicit(ptr.ToInt32 + nOffset)
Next
b.UnlockBits(bmData)
Return b
End Function
End Class
Public Class Form1
Dim op As OpenFileDialog
Private Sub TrackBar1_Scroll(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles TrackBar1.Scroll
On Error Resume Next
Filters.BrightnessFilter(TrackBar1.Value, CType(PictureBox1.Image, Bitmap))
PictureBox1.Refresh()
Cursor.Current = Cursors.Arrow
End Sub
Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
TrackBar1.Minimum = -255
TrackBar1.Maximum = 255
TrackBar2.Minimum = -255
TrackBar2.Maximum = 255
End Sub
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
If OpenFileDialog1.ShowDialog = Windows.Forms.DialogResult.OK Then
PictureBox1.ImageLocation = OpenFileDialog1.FileName
PictureBox1.SizeMode = PictureBoxSizeMode.StretchImage
End If
End Sub
Private Sub TrackBar2_Scroll(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles TrackBar2.Scroll
Filters.ContrastFilter(TrackBar2.Value, CType(PictureBox1.Image, Bitmap))
PictureBox1.Refresh()
Cursor.Current = Cursors.Arrow
End Sub
End Class
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