Color Scale Filter

' Demonstration project for gray and color scale image filter.
' 
' Copyright (c) 2007 Miran Uhan
' 
' This program is free software; you can redistribute it and/or modify
' it under the terms of the GNU General Public License as published by
' the Free Software Foundation; either version 2 of the License, or
' (at your option) any later version.
'
' This program is distributed in the hope that it will be useful,
' but WITHOUT ANY WARRANTY; without even the implied warranty of
' MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
' GNU General Public License for more details.
'
' You should have received a copy of the GNU General Public License
' along with this program; if not, write to the
'    Free Software Foundation, Inc.
'    51 Franklin Street, Fifth Floor
'    Boston, MA 02110-1301 USA
'
' For questions you can contact author at
'    miran.uhan@gmail.com
' Sugestions and bug reports are also welcome.
' 

Imports System.Drawing
Imports System.Drawing.Imaging

Public Class frmMain

   Private _imgOriginal As Image
   Private _imgFiltered As Image
   Private _imgResized As Image
   Private _filterGray As GrayScaleFilter = New GrayScaleFilter
   Private _filterColor As ColorScaleFilter = New ColorScaleFilter
   Private _mouseDown As Boolean = False

   Public Shared Function GetEncoderInfo(ByVal format As ImageFormat) As ImageCodecInfo
      Dim j As Integer
      Dim encoders() As ImageCodecInfo
      encoders = ImageCodecInfo.GetImageEncoders()
      j = 0
      While j < encoders.Length
         If encoders(j).FormatID = format.Guid Then
            Return encoders(j)
         End If
         j += 1
      End While
      Return Nothing
   End Function

   Private Sub FilterImageGray()
      If (Not IsNothing(pnlOriginal.BackgroundImage)) Then
         pnlFiltered.BackgroundImage = Nothing
         pnlFiltered.BackgroundImage = _filterGray.ExecuteFilter(_imgResized)
      End If
   End Sub

   Private Sub FilterImageColor()
      If (Not IsNothing(pnlOriginal.BackgroundImage)) Then
         pnlFiltered.BackgroundImage = Nothing
         pnlFiltered.BackgroundImage = _filterColor.ExecuteFilter(_imgResized)
      End If
   End Sub

   Private Sub WhenTextChange(ByVal textBox As TextBox, ByVal slider As TrackBar)
      Try
         Dim value As Integer = 0
         If (textBox.Text = "") Or (textBox.Text = "-") Or (textBox.Text = "+") Then
            value = 0
         Else
            value = CInt(textBox.Text)
         End If
         slider.Value = value
      Catch ex As Exception
         textBox.Text = slider.Value.ToString()
      End Try
   End Sub

   Private Sub frmMain_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
      SaveAsToolStripMenuItem.Enabled = False
      picStartColor.BackColor = Color.FromArgb(102, 51, 51)
      pnlOriginal.BackgroundImage = Nothing
      pnlFiltered.BackgroundImage = Nothing
   End Sub

   Private Sub OpenToolStripMenuItem_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles OpenToolStripMenuItem.Click
      Dim result As DialogResult = dlgFileOpen.ShowDialog()
      If result = Windows.Forms.DialogResult.OK Then
         _imgOriginal = Image.FromFile(dlgFileOpen.FileName)
         Dim scale As Double = 1
         If (_imgOriginal.Width > 280) Or (_imgOriginal.Height > 210) Then
            scale = System.Math.Min(280 / _imgOriginal.Width, 210 / _imgOriginal.Height)
         End If
         Dim imgFilter As ResizeFilter = New ResizeFilter
         imgFilter.Width = CInt(scale * _imgOriginal.Width)
         imgFilter.Height = CInt(scale * _imgOriginal.Height)
         _imgResized = imgFilter.ExecuteFilter(_imgOriginal)
         pnlOriginal.BackgroundImage = _imgResized
         If tabMain.SelectedTab.Equals(tabGray) Then
            pnlFiltered.BackgroundImage = _filterGray.ExecuteFilter(_imgResized)
         Else
            pnlFiltered.BackgroundImage = _filterColor.ExecuteFilter(_imgResized)
         End If
         SaveAsToolStripMenuItem.Enabled = True
      End If
   End Sub

   Private Sub SaveAsToolStripMenuItem_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles SaveAsToolStripMenuItem.Click
      dlgFileSave.FileName = ""
      Dim result As DialogResult = dlgFileSave.ShowDialog()
      If result = Windows.Forms.DialogResult.OK Then
         Me.Cursor = Cursors.WaitCursor
         Dim ext As String = Mid(dlgFileSave.FileName, dlgFileSave.FileName.LastIndexOf(".") + 2)
         Dim myEncoderParameters As EncoderParameters = Nothing
         Dim myImageCodecInfo As ImageCodecInfo
         Select Case ext.ToLower()
            Case "jpg"
               myImageCodecInfo = GetEncoderInfo(ImageFormat.Jpeg)
               myEncoderParameters = New EncoderParameters(1)
               myEncoderParameters.Param(0) = New EncoderParameter(Encoder.Quality, CType(90L, Int32))
            Case "gif"
               myImageCodecInfo = GetEncoderInfo(ImageFormat.Gif)
            Case "png"
               myImageCodecInfo = GetEncoderInfo(ImageFormat.Png)
            Case "bmp"
               myImageCodecInfo = GetEncoderInfo(ImageFormat.Bmp)
            Case Else
               MsgBox("Image format " & ext & " is not suported!", MsgBoxStyle.Exclamation)
               Exit Sub
         End Select
         If tabMain.SelectedTab.Equals(tabGray) Then
            _imgFiltered = _filterGray.ExecuteFilter(_imgOriginal)
         Else
            _imgFiltered = _filterColor.ExecuteFilter(_imgOriginal)
         End If
         _imgFiltered.Save(dlgFileSave.FileName, myImageCodecInfo, myEncoderParameters)
         Me.Cursor = Cursors.Default
      End If
   End Sub

   Private Sub ExitToolStripMenuItem_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles ExitToolStripMenuItem.Click
      Me.Close()
   End Sub

   Private Sub rdbGrayNormal_CheckedChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles rdbGrayNormal.CheckedChanged
      _filterGray.Brightness = Brightness.Normal
      _sliderGrayRed.Enabled = False
      _sliderGrayRed.Value = 30
      _txtGrayRed.Enabled = False
      _txtGrayRed.Text = "30"
      _sliderGrayGreen.Enabled = False
      _sliderGrayGreen.Value = 59
      _txtGrayGreen.Enabled = False
      _txtGrayGreen.Text = "59"
      _sliderGrayBlue.Enabled = False
      _sliderGrayBlue.Value = 11
      _txtGrayBlue.Enabled = False
      _txtGrayBlue.Text = "11"
      FilterImageGray()
   End Sub

   Private Sub rdbGrayBright_CheckedChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles rdbGrayBright.CheckedChanged
      _filterGray.Brightness = Brightness.Bright
      _sliderGrayRed.Enabled = False
      _sliderGrayRed.Value = 50
      _txtGrayRed.Enabled = False
      _txtGrayRed.Text = "50"
      _sliderGrayGreen.Enabled = False
      _sliderGrayGreen.Value = 50
      _txtGrayGreen.Enabled = False
      _txtGrayGreen.Text = "50"
      _sliderGrayBlue.Enabled = False
      _sliderGrayBlue.Value = 50
      _txtGrayBlue.Enabled = False
      _txtGrayBlue.Text = "50"
      FilterImageGray()
   End Sub

   Private Sub rdbGrayCustom_CheckedChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles rdbGrayCustom.CheckedChanged
      _filterGray.Brightness = Brightness.Custom
      _sliderGrayRed.Enabled = True
      _txtGrayRed.Enabled = True
      _sliderGrayGreen.Enabled = True
      _txtGrayGreen.Enabled = True
      _sliderGrayBlue.Enabled = True
      _txtGrayBlue.Enabled = True
   End Sub

   Private Sub sliderGrayRed_MouseDown(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles sliderGrayRed.MouseDown
      _mouseDown = True
   End Sub

   Private Sub sliderGrayRed_MouseUp(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles sliderGrayRed.MouseUp
      _mouseDown = False
      If (CDbl(sliderGrayRed.Value) <> _filterGray.FactorRed) Then
         _filterGray.FactorRed = CDbl(sliderGrayRed.Value)
         FilterImageGray()
      End If
   End Sub

   Private Sub sliderGrayRed_Scroll(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles sliderGrayRed.Scroll
      txtGrayRed.Text = sliderGrayRed.Value.ToString()
   End Sub

   Private Sub sliderGrayGreen_MouseDown(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles sliderGrayGreen.MouseDown
      _mouseDown = True
   End Sub

   Private Sub sliderGrayGreen_MouseUp(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles sliderGrayGreen.MouseUp
      _mouseDown = False
      If (CDbl(sliderGrayGreen.Value) <> _filterGray.FactorGreen) Then
         _filterGray.FactorGreen = CDbl(sliderGrayGreen.Value)
         FilterImageGray()
      End If
   End Sub

   Private Sub sliderGrayGreen_Scroll(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles sliderGrayGreen.Scroll
      txtGrayGreen.Text = sliderGrayGreen.Value.ToString()
   End Sub

   Private Sub sliderGrayBlue_MouseDown(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles sliderGrayBlue.MouseDown
      _mouseDown = True
   End Sub

   Private Sub sliderGrayBlue_MouseUp(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles sliderGrayBlue.MouseUp
      _mouseDown = False
      If (CDbl(sliderGrayBlue.Value) <> _filterGray.FactorBlue) Then
         _filterGray.FactorBlue = CDbl(sliderGrayBlue.Value)
         FilterImageGray()
      End If
   End Sub

   Private Sub sliderGrayBlue_Scroll(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles sliderGrayBlue.Scroll
      txtGrayBlue.Text = sliderGrayBlue.Value.ToString()
   End Sub

   Private Sub txtGrayRed_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles txtGrayRed.TextChanged
      If (Not _mouseDown) Then
         WhenTextChange(txtGrayRed, sliderGrayRed)
         If (CDbl(sliderGrayRed.Value) <> _filterGray.FactorRed) Then
            _filterGray.FactorRed = CDbl(sliderGrayRed.Value)
            FilterImageGray()
         End If
      End If
   End Sub

   Private Sub txtGrayGreen_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles txtGrayGreen.TextChanged
      If (Not _mouseDown) Then
         WhenTextChange(txtGrayGreen, sliderGrayGreen)
         If (CDbl(sliderGrayGreen.Value) <> _filterGray.FactorGreen) Then
            _filterGray.FactorGreen = CDbl(sliderGrayGreen.Value)
            FilterImageGray()
         End If
      End If
   End Sub

   Private Sub txtGrayBlue_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles txtGrayBlue.TextChanged
      If (Not _mouseDown) Then
         WhenTextChange(txtGrayBlue, sliderGrayBlue)
         If (CDbl(sliderGrayBlue.Value) <> _filterGray.FactorBlue) Then
            _filterGray.FactorBlue = CDbl(sliderGrayBlue.Value)
            FilterImageGray()
         End If
      End If
   End Sub

   Private Sub rdbColorNormal_CheckedChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles rdbColorNormal.CheckedChanged
      _filterColor.Brightness = Brightness.Normal
      _sliderColorRed.Enabled = False
      _sliderColorRed.Value = 30
      _txtColorRed.Enabled = False
      _txtColorRed.Text = "30"
      _sliderColorGreen.Enabled = False
      _sliderColorGreen.Value = 59
      _txtColorGreen.Enabled = False
      _txtColorGreen.Text = "59"
      _sliderColorBlue.Enabled = False
      _sliderColorBlue.Value = 11
      _txtColorBlue.Enabled = False
      _txtColorBlue.Text = "11"
      FilterImageColor()
   End Sub

   Private Sub rdbColorBright_CheckedChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles rdbColorBright.CheckedChanged
      _filterColor.Brightness = Brightness.Bright
      _sliderColorRed.Enabled = False
      _sliderColorRed.Value = 50
      _txtColorRed.Enabled = False
      _txtColorRed.Text = "50"
      _sliderColorGreen.Enabled = False
      _sliderColorGreen.Value = 50
      _txtColorGreen.Enabled = False
      _txtColorGreen.Text = "50"
      _sliderColorBlue.Enabled = False
      _sliderColorBlue.Value = 50
      _txtColorBlue.Enabled = False
      _txtColorBlue.Text = "50"
      FilterImageColor()
   End Sub

   Private Sub rdbColorCustom_CheckedChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles rdbColorCustom.CheckedChanged
      _filterColor.Brightness = Brightness.Custom
      _sliderColorRed.Enabled = True
      _txtColorRed.Enabled = True
      _sliderColorGreen.Enabled = True
      _txtColorGreen.Enabled = True
      _sliderColorBlue.Enabled = True
      _txtColorBlue.Enabled = True
   End Sub

   Private Sub sliderColorRed_MouseDown(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles sliderColorRed.MouseDown
      _mouseDown = True
   End Sub

   Private Sub sliderColorRed_MouseUp(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles sliderColorRed.MouseUp
      _mouseDown = False
      If (CDbl(sliderColorRed.Value) <> _filterColor.FactorRed) Then
         _filterColor.FactorRed = CDbl(sliderColorRed.Value)
         FilterImageColor()
      End If
   End Sub

   Private Sub sliderColorRed_Scroll(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles sliderColorRed.Scroll
      txtColorRed.Text = sliderColorRed.Value.ToString()
   End Sub

   Private Sub sliderColorGreen_MouseDown(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles sliderColorGreen.MouseDown
      _mouseDown = True
   End Sub

   Private Sub sliderColorGreen_MouseUp(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles sliderColorGreen.MouseUp
      _mouseDown = False
      If (CDbl(sliderColorGreen.Value) <> _filterColor.FactorGreen) Then
         _filterColor.FactorGreen = CDbl(sliderColorGreen.Value)
         FilterImageColor()
      End If
   End Sub

   Private Sub sliderColorGreen_Scroll(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles sliderColorGreen.Scroll
      txtColorGreen.Text = sliderColorGreen.Value.ToString()
   End Sub

   Private Sub sliderColorBlue_MouseDown(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles sliderColorBlue.MouseDown
      _mouseDown = True
   End Sub

   Private Sub sliderColorBlue_MouseUp(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles sliderColorBlue.MouseUp
      _mouseDown = False
      If (CDbl(sliderColorBlue.Value) <> _filterColor.FactorBlue) Then
         _filterColor.FactorBlue = CDbl(sliderColorBlue.Value)
         FilterImageColor()
      End If
   End Sub

   Private Sub sliderColorBlue_Scroll(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles sliderColorBlue.Scroll
      txtColorBlue.Text = sliderColorBlue.Value.ToString()
   End Sub

   Private Sub txtColorRed_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles txtColorRed.TextChanged
      If (Not _mouseDown) Then
         WhenTextChange(txtColorRed, sliderColorRed)
         If (CDbl(sliderColorRed.Value) <> _filterColor.FactorRed) Then
            _filterColor.FactorRed = CDbl(sliderColorRed.Value)
            FilterImageColor()
         End If
      End If
   End Sub

   Private Sub txtColorGreen_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles txtColorGreen.TextChanged
      If (Not _mouseDown) Then
         WhenTextChange(txtColorGreen, sliderColorGreen)
         If (CDbl(sliderColorGreen.Value) <> _filterColor.FactorGreen) Then
            _filterColor.FactorGreen = CDbl(sliderColorGreen.Value)
            FilterImageColor()
         End If
      End If
   End Sub

   Private Sub txtColorBlue_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles txtColorBlue.TextChanged
      If (Not _mouseDown) Then
         WhenTextChange(txtColorBlue, sliderColorBlue)
         If (CDbl(sliderColorBlue.Value) <> _filterColor.FactorBlue) Then
            _filterColor.FactorBlue = CDbl(sliderColorBlue.Value)
            FilterImageColor()
         End If
      End If
   End Sub

   Private Sub tabMain_SelectedIndexChanged(ByVal sender As Object, ByVal e As System.EventArgs) Handles tabMain.SelectedIndexChanged
      If tabMain.SelectedTab.Equals(tabGray) Then
         FilterImageGray()
      Else
         FilterImageColor()
      End If
   End Sub

   Private Sub btnStartColor_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnStartColor.Click
      Dim result As DialogResult = dlgColor.ShowDialog()
      If result = Windows.Forms.DialogResult.OK Then
         Dim c As Color = dlgColor.Color
         picStartColor.BackColor = c
         _filterColor.StartColor = c
         FilterImageColor()
      End If
   End Sub

   Private Sub btnEndColor_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnEndColor.Click
      Dim result As DialogResult = dlgColor.ShowDialog()
      If result = Windows.Forms.DialogResult.OK Then
         Dim c As Color = dlgColor.Color
         picEndColor.BackColor = c
         _filterColor.EndColor = c
         FilterImageColor()
      End If
   End Sub

End Class