how to replace color without mastk

Question

hi guys.. i need replace color image without mask
example:

This person's picture has a green background. When I replace the green color to another color, it also replaces the color of the card
I drew a rectangle on the card, how do I exclude the rectangle from the replacement

replace color code:

    Public Function ReplaceColor(ByVal _image As Image, ByVal _colorOld As Color, ByVal _colorNew As Color, ByVal _tolerance As Integer) As Image  
        Dim bmap As Bitmap = CType(_image.Clone(), Bitmap)  
        Dim c As Color  
        Dim iR_Min, iR_Max As Integer  
        Dim iG_Min, iG_Max As Integer  
        Dim iB_Min, iB_Max As Integer  
        iR_Min = Math.Max(CInt(_colorOld.R) - _tolerance, 0)  
        iR_Max = Math.Min(CInt(_colorOld.R) + _tolerance, 255)  
        iG_Min = Math.Max(CInt(_colorOld.G) - _tolerance, 0)  
        iG_Max = Math.Min(CInt(_colorOld.G) + _tolerance, 255)  
        iB_Min = Math.Max(CInt(_colorOld.B) - _tolerance, 0)  
        iB_Max = Math.Min(CInt(_colorOld.B) + _tolerance, 255)  
  
        For x As Integer = 0 To bmap.Width - 1  
  
            For y As Integer = 0 To bmap.Height - 1  
                c = bmap.GetPixel(x, y)  
  
                If (c.R >= iR_Min AndAlso c.R <= iR_Max) AndAlso (c.G >= iG_Min AndAlso c.G <= iG_Max) AndAlso (c.B >= iB_Min AndAlso c.B <= iB_Max) Then  
  
                    If _colorNew = Color.Transparent Then  
                        bmap.SetPixel(x, y, Color.FromArgb(0, _colorNew.R, _colorNew.G, _colorNew.B))  
                    Else  
                        bmap.SetPixel(x, y, Color.FromArgb(c.A, _colorNew.R, _colorNew.G, _colorNew.B))  
                    End If  
  
                End If  
            Next  
        Next  
  
        Return CType(bmap.Clone(), Image)  
    End Function  

my rectangle mastk info:

Private Rct2 As New Rectangle(247, 378, 100, 70)

Answer 1

Try adding an If inside your loops:

For x As Integer = 0 To bmap.Width - 1
   For y As Integer = 0 To bmap.Height - 1
      If Rct2.Contains(x, y) Then Continue For
. . .