Как изменить цвет пикселей во всем изображении?

Public Function ConvertPixels(ByVal b As Bitmap, ByVal cFrom As Color, ByVal cTo As Color) As Bitmap
  For i As Integer = 0 To b.Width - 1 
    For j As Integer = 0 To b.Height - 1
      If b.GetPixel(i, j) = cFrom Then
        b.SetPixel(i, j, cTo)
      End If
    Next j
  Next i
  Return b
End Function

  Dim image1 As Bitmap
    Dim nmd, path As String
    Dim pixelColor As Color
    Dim x, y, k, j As Integer
 
    Private Sub Button1_Click(ByVal sender As System.Object, _
        ByVal e As System.EventArgs) Handles Button1.Click
        If nmd = "" Then nmd = "*"
        With OpenFileDialog1
            .InitialDirectory = nmd
            .RestoreDirectory = True
            .FileName = ""
            .Filter = "Image Files|*.jpg;*.bmp;*.png"
            .FilterIndex = 1
            .CheckFileExists = True
            .Title = "Select Open Video Files"
        End With
        If OpenFileDialog1.ShowDialog = Windows.Forms.DialogResult.OK Then
            path = OpenFileDialog1.FileName
        End If
     Timer1.Enabled = True
        Timer1.Interval = 200
        Timer1.Start()
    End Sub
 
 Private Sub Timer1_Tick(sender As System.Object, e As System.EventArgs) Handles Timer1.Tick
        Label2.Text = k & "  " & j & "  " & pixelColor.Name
        If k < 100 And j < 100 Then
            pixelColor = image1.GetPixel(k, j)
            Label3.Text = pixelColor.ToArgb
            Dim newColor As Color = Color.FromArgb(25, 47, 0)
            image1.SetPixel(k, j, newColor)
            k = k + 1
            j = j + 1
        End If
    End Sub

   Dim nmd, path As String
 
    Private Sub Button1_Click(sender As System.Object, e As System.EventArgs) Handles Button1.Click
        Dim b As Bitmap = New Bitmap(path)  '  "D:\test.bmp")
 
        ' Make Image Indexed
 
        Dim nii As New Bitmap(b.Width, b.Height, System.Drawing.Imaging.PixelFormat.Format32bppPArgb)
        For y As Integer = 0 To nii.Height - 1
            For x = 0 To nii.Width - 1
                Dim cw As New Color
                cw = Color.Black
                If nii.GetPixel(x, y) = cw Then
                    nii.SetPixel(x, y, Color.Red)
                Else
                    nii.SetPixel(x, y, Color.Red)
                End If
 
            Next
        Next
        '   PictureBox1.Image = Image.FromFile(path)  '   "D:\test.bmp")
 
    End Sub
 
    Private Sub Form1_Load(sender As System.Object, e As System.EventArgs) Handles MyBase.Load
   If nmd = "" Then nmd = "*"
        With OpenFileDialog1
            .InitialDirectory = nmd
            .RestoreDirectory = True
            .FileName = ""
            .Filter = "Image Files|*.jpg;*.bmp;*.png"
            .FilterIndex = 1
            .CheckFileExists = True
            .Title = "Select Open Video Files"
        End With
        If OpenFileDialog1.ShowDialog = Windows.Forms.DialogResult.OK Then
            path = OpenFileDialog1.FileName
        End If
        PictureBox1.Image = Image.FromFile(path)
    End Sub
End Class

Public Class Form1
 
    Dim ds, sa As Integer
 
    Private Sub Button1_Click(sender As System.Object, e As System.EventArgs) Handles Button1.Click
        For sa = 0 To 10
            For ds = 0 To 10
                TextBox1.Text = TextBox1.Text & ds & "- ds" & vbCrLf
 
            Next
            TextBox2.Text = TextBox2.Text & sa & "- sa" & vbCrLf
        Next
    End Sub
 
    Private Sub Button2_Click(sender As System.Object, e As System.EventArgs) Handles Button2.Click
        For i As Integer = 0 To 10
            For j As Integer = 0 To 10
                TextBox1.Text = TextBox1.Text & j & "- j" & vbCrLf
 
            Next j
            TextBox2.Text = TextBox2.Text & i & "- i" & vbCrLf
        Next i
    End Sub
End Class

Imports System.Drawing.Drawing2D
 
Public Class Form1
 
    Dim nmd, path As String
    Dim x, y As Integer
 
    Private Sub Button1_Click(sender As System.Object, e As System.EventArgs) Handles Button1.Click
        Dim b As Bitmap = New Bitmap(path)  '  "D:\test.bmp")
 
        ' Make Image Indexed
        Dim j, i As Integer
        Dim MyBitmap As Bitmap
        MyBitmap = CType(PictureBox1.Image, Bitmap)
           For i = 0 To MyBitmap.Height - 2
            For j = 0 To MyBitmap.Width - 2
                MyBitmap.SetPixel(i, j, Color.Red)
            Next j
                 Next i
        PictureBox1.Refresh()
        If i = MyBitmap.Width - 1 And j = MyBitmap.Height - 1 Then MsgBox("Finish")
          End Sub
 
    Private Sub Form1_Load(sender As System.Object, e As System.EventArgs) Handles MyBase.Load
   If nmd = "" Then nmd = "*"
        With OpenFileDialog1
            .InitialDirectory = nmd
            .RestoreDirectory = True
            .FileName = ""
            .Filter = "Image Files|*.jpg;*.bmp;*.png"
            .FilterIndex = 1
            .CheckFileExists = True
            .Title = "Select Open Video Files"
        End With
        If OpenFileDialog1.ShowDialog = Windows.Forms.DialogResult.OK Then
            path = OpenFileDialog1.FileName
        End If
        PictureBox1.Image = Image.FromFile(path)
    End Sub
 
   
End Class

Imports System.IO
Imports System.Drawing.Imaging
Public Class Form4
    Dim bmp As Bitmap
    Private Sub Form4_Load(sender As System.Object, e As System.EventArgs) Handles MyBase.Load
        bmp = New Bitmap(Path.Combine(Application.StartupPath, "tst1.png"))
        PictureBox1.Image = bmp
    End Sub
    Private Sub Button1_Click(sender As System.Object, e As System.EventArgs) Handles Button1.Click
        Dim bR As Byte = NumericUpDown1.Value
        Dim bB As Byte = NumericUpDown2.Value
        If bB > bR Then
            PictureBox1.Image = colorMapping(bmp, bR, bB) 'bR-красная граница; bB-синяя граница
        End If
        Button1.Enabled = False
    End Sub
    Public Function colorMapping(ByVal bm As Bitmap, ByVal btR As Byte, ByVal btB As Byte) As Bitmap
        Dim rect As New Rectangle(0, 0, bm.Width, bm.Height)
        Dim bmpData As BitmapData = bm.LockBits(rect, Drawing.Imaging.ImageLockMode.ReadWrite, bm.PixelFormat)
        Dim ptr As IntPtr = bmpData.Scan0
        Dim allbytes As Integer = bmpData.Stride * bm.Height
        Dim rgbV(allbytes - 1) As Byte
        System.Runtime.InteropServices.Marshal.Copy(ptr, rgbV, 0, allbytes)
        Dim bt As Byte
        For i As Integer = 0 To rgbV.Length - 4 Step 4
            bt = rgbV(i)
            If bt < btR OrElse bt > btB Then
                rgbV(i) = 255
                rgbV(i + 1) = 255
                rgbV(i + 2) = 255
                rgbV(i + 3) = 255
            Else
                rgbV(i) = 0
                rgbV(i + 1) = 0
                rgbV(i + 2) = 0
                rgbV(i + 3) = 255
            End If
        Next
        System.Runtime.InteropServices.Marshal.Copy(rgbV, 0, ptr, allbytes)
        bm.UnlockBits(bmpData)
        Return bm
    End Function
End Class

Imports System.IO
Imports System.Drawing.Imaging
Public Class Form5
    Private bmp As Bitmap
    Private n, m As Integer
    Private Sub Form5_Load(sender As System.Object, e As System.EventArgs) Handles MyBase.Load
        Dim bmp As New Bitmap(Path.Combine(Application.StartupPath, "tst2.png"))
        n = bmp.Width : m = bmp.Height
        NumericUpDown1.Minimum = 0
        NumericUpDown1.Maximum = n - 1
        NumericUpDown2.Minimum = 0
        NumericUpDown2.Maximum = m - 1
        PictureBox1.Image = bmp
    End Sub
    Private Sub Button1_Click(sender As System.Object, e As System.EventArgs) Handles Button1.Click
        Dim bm As Bitmap = New Bitmap(n, m, PixelFormat.Format24bppRgb)
        PictureBox1.Image = bm
        'bR-красная граница; bB-синяя граница; здесь координата X в пиксельных координатах
        Dim bR As Integer = NumericUpDown1.Value
        Dim bB As Integer = NumericUpDown2.Value
        If bB > bR Then
            PictureBox1.Image = colorMapping(bm, bR, bB)
        End If
    End Sub
    Public Function colorMapping(ByVal btmap As Bitmap, ByVal btR As Integer, ByVal btB As Integer) As Bitmap
        Dim bm As Bitmap = btmap
        Dim cc As Color
        For i = 0 To m - 1
            For j = 0 To btR
                cc = Color.White
                bm.SetPixel(j, i, cc)
            Next
        Next
        For i = 0 To m - 1
            For j = btB To n - 1
                cc = Color.White
                bm.SetPixel(j, i, cc)
            Next
        Next
        Return bm
    End Function
End Class

Imports System.Drawing.Imaging
Imports System.IO
Public Class Form6
    Private src, bmp As Bitmap
    Private Sub Form6_Load(sender As System.Object, e As System.EventArgs) Handles MyBase.Load
        bmp = New Bitmap(Path.Combine(Application.StartupPath, "clr1.jpg"))
        PictureBox1.Image = bmp
    End Sub
    Private Sub Button1_Click(sender As System.Object, e As System.EventArgs) Handles Button1.Click
        src = bmp.Clone
        toBW(TrackBar1.Value / 100)
        PictureBox2.Image = src
    End Sub
    Private Sub toBW(ByVal th As Single)
        Using gr As Graphics = Graphics.FromImage(src)
            Dim gray_matrix As Single()() = {
              New Single() {0.299F, 0.299F, 0.299F, 0, 0},
              New Single() {0.587F, 0.587F, 0.587F, 0, 0},
              New Single() {0.114F, 0.114F, 0.114F, 0, 0},
              New Single() {0, 0, 0, 1, 0},
              New Single() {0, 0, 0, 0, 1}
            }
            Dim ia As New System.Drawing.Imaging.ImageAttributes
            ia.SetColorMatrix(New System.Drawing.Imaging.ColorMatrix(gray_matrix))
            ia.SetThreshold(th)
            Dim rc As New Rectangle(0, 0, src.Width, src.Height)
            gr.DrawImage(src, rc, 0, 0, src.Width, src.Height, GraphicsUnit.Pixel, ia)
        End Using
    End Sub
End Class

Path.Combine(Application.StartupPath, "clr1.jpg")

Imports System.Drawing.Drawing2D
Imports System.Runtime.InteropServices
Imports Microsoft.VisualBasic.Devices
 
Public Class Form1
 
    Dim nmd, path As String
    Dim x, y, ph, pw As Integer
    Dim hp, wp As Integer
    Dim myColor As System.Drawing.Color
    Dim b, image1 As Bitmap
    Dim g As Graphics
 
    '[
    Private Declare Function GetPixel Lib "gdi32" (ByVal hdc As Integer, ByVal x As Integer, ByVal y As Integer) As Integer
    Private Declare Function GetDesktopWindow Lib "user32" () As Integer
    Private Declare Function GetWindowDC Lib "user32" (ByVal hwnd As Integer) As Integer
    Private Sub GetPoint(ByVal x As Double, ByVal y As Double)
        Dim DC, hwnd, Color As Integer
        hwnd = GetDesktopWindow
        DC = GetWindowDC(hwnd)
        Color = GetPixel(DC, x, y)
        Label1.Text = Color
        Label1.BackColor = ColorTranslator.FromWin32(Color)
    End Sub
    'p
    Private Function Pixel(Hwnd As Integer, x As Integer, y As Integer)
        Return GetPixel(GetWindowDC(Hwnd), x, y)
    End Function
    ']
 
    Private Sub Button1_Click(sender As System.Object, e As System.EventArgs) Handles Button1.Click
        Dim b As Bitmap = New Bitmap(path)  '  "D:\test.bmp")
        ListBox1.Items.Clear()
        Dim j, i As Integer
        Dim MyBitmap As Bitmap
        MyBitmap = CType(PictureBox1.Image, Bitmap)
        image1 = New Bitmap(path, True)
        g = Graphics.FromImage(image1)
        For j = 0 To MyBitmap.Height - 2
            For i = 0 To MyBitmap.Width - 2
                Dim gp = MyBitmap.GetPixel(i, j)
                myColor = MyBitmap.GetPixel(i, j)
                Application.DoEvents()
                If myColor.Name = "ffc0c0c0" Then MyBitmap.SetPixel(i, j, Color.White)
                If myColor.Name = "ff333333" Then MyBitmap.SetPixel(i, j, Color.Black)
                If myColor.Name = "ff484848" Then MyBitmap.SetPixel(i, j, Color.Black)
                If myColor.Name = "ffe7e7e7" Then MyBitmap.SetPixel(i, j, Color.White)
                If myColor.Name = "ff010101" Then MyBitmap.SetPixel(i, j, Color.Black)
                If myColor.Name = "ffefefef" Then MyBitmap.SetPixel(i, j, Color.White)
                If myColor.Name = "ffe5e5e5" Then MyBitmap.SetPixel(i, j, Color.White)
                If myColor.Name = "fffefefe" Then MyBitmap.SetPixel(i, j, Color.White)
                If myColor.Name = "fffafafa" Then MyBitmap.SetPixel(i, j, Color.White)
                If myColor.Name = "ff717171" Then MyBitmap.SetPixel(i, j, Color.White)
                If myColor.Name = "fffbfbfb" Then MyBitmap.SetPixel(i, j, Color.White)
                If myColor.Name = "ff717171" Then MyBitmap.SetPixel(i, j, Color.White)
                If myColor.Name = "ffb9b9b9" Then MyBitmap.SetPixel(i, j, Color.White)
                If myColor.Name = "ffd9d9d9" Then MyBitmap.SetPixel(i, j, Color.White)
                If myColor.Name = "ffbdbdbd" Then MyBitmap.SetPixel(i, j, Color.White)
                If myColor.Name = "ffeeeeee" Then MyBitmap.SetPixel(i, j, Color.White)
                If myColor.Name = "ffc8c8c8" Then MyBitmap.SetPixel(i, j, Color.White)
                If myColor.Name = "ffa4a4a4" Then MyBitmap.SetPixel(i, j, Color.Black)
                If myColor.Name = "ffcdcdcd" Then MyBitmap.SetPixel(i, j, Color.Black)
                If myColor.Name = "ffcacaca" Then MyBitmap.SetPixel(i, j, Color.Black)
                If myColor.Name = "fff3f3f3" Then MyBitmap.SetPixel(i, j, Color.Black)
                If myColor.Name = "ffcacaca" Then MyBitmap.SetPixel(i, j, Color.Black)
                If myColor.Name = "ffdddddd" Then MyBitmap.SetPixel(i, j, Color.Black)
                If myColor.Name = "ffcccccc" Then MyBitmap.SetPixel(i, j, Color.Black)
                If myColor.Name = "ff020202" Then MyBitmap.SetPixel(i, j, Color.Black)
                If myColor.Name = "ff313131" Then MyBitmap.SetPixel(i, j, Color.Black)
                If myColor.Name = "ff030303" Then MyBitmap.SetPixel(i, j, Color.Black)
                If myColor.Name = "ffa4a4a4" Then MyBitmap.SetPixel(i, j, Color.Black)
                If myColor.Name = "ff888888" Then MyBitmap.SetPixel(i, j, Color.Black)
                If myColor.Name = "ff959595" Then MyBitmap.SetPixel(i, j, Color.Black)
                If myColor.Name = "ff858585" Then MyBitmap.SetPixel(i, j, Color.Black)
                If myColor.Name = "ffc4c4c4" Then MyBitmap.SetPixel(i, j, Color.Black)
                If myColor.Name = "ffc9c9c9" Then MyBitmap.SetPixel(i, j, Color.Black)
                If myColor.Name = "ffe4e4e4" Then MyBitmap.SetPixel(i, j, Color.White)
                If myColor.Name = "ff8f8f8f" Then MyBitmap.SetPixel(i, j, Color.White)
                If myColor.Name = "ffe4e4e4" Then MyBitmap.SetPixel(i, j, Color.White)
                If myColor.Name = "ff6c6c6c" Then MyBitmap.SetPixel(i, j, Color.White)
            Next i
        Next j
        PictureBox1.Refresh()
        If i = MyBitmap.Width - 1 And j = MyBitmap.Height - 1 Then Me.Text = "Finish"
        Timer1.Enabled = True
        Timer1.Interval = 100
        Timer1.Start()
 
    End Sub
 
    Private Sub Form1_Load(sender As System.Object, e As System.EventArgs) Handles MyBase.Load
      
    End Sub
 
    Private Sub Button2_Click(sender As System.Object, e As System.EventArgs) Handles Button2.Click
        PictureBox1.Image = Image.FromFile(path)
    End Sub
 
    Private Sub Button3_Click(sender As System.Object, e As System.EventArgs) Handles Button3.Click
        If nmd = "" Then nmd = "*"
        With OpenFileDialog1
            .InitialDirectory = nmd
            .RestoreDirectory = True
            .FileName = ""
            .Filter = "Image Files|*.jpg;*.bmp;*.png"
            .FilterIndex = 1
            .CheckFileExists = True
            .Title = "Select Open Video Files"
        End With
        If OpenFileDialog1.ShowDialog = Windows.Forms.DialogResult.OK Then
            path = OpenFileDialog1.FileName
        End If
        PictureBox1.Image = Image.FromFile(path)
    End Sub
End Class

Dim colors As New Dictionary(Of String, Color)() From { _
    {"ffc0c0c0", Color.White}, _
    {"ff333333", Color.Black}, _
    {"ff484848", Color.Black}, _
    {"ffe7e7e7", Color.White} _
}
For Each color__1 As var In colors
    If myColor.Name = color__1.Key Then
        MyBitmap.SetPixel(0, 0, color__1.Value)
    End If
Next

For Each color As var In colors.Where(Function(color) myColor.Name = color.Key)
    MyBitmap.SetPixel(0, 0, color.Value)
Next

MyBitmap.SetPixel(0, 0, color__1[myColor.Name])