自己胡乱想出来的几个自定义的图像颜色处理方法：

1、R、G、B中最大的

R最大返回(255,0)

G最大返回(0,255,0)

B最大返回(0,255)

2、R、G、B中最大的

R最大返回(R,G,B)

3、R、G、B中最大的

R最大返回(R,R,R)

G最大返回(G,G)

B最大返回(B,B,B)

用到一个自定义方法，返回R、G、B中最大的值的分量名称

    Private Function getMax(ByVal r As Integer,ByVal g As Integer,ByVal b As Integer) As String
        If r > g And r > b Then Return "r"
        If g > r And g > b Then Return "g"
        If b > r And b > g Then Return "b"
        Return "b"
    End Function

主要代码：

    '自定义1
    Private Sub btnCustom1_Click(sender As Object,e As EventArgs) Handles btnCustom1.Click
        Dim pSourceColor As Color
        Dim pDestColor As Color

        Dim destImg As New Bitmap(sourceImg.Width,sourceImg.Height)
        Dim R,B As Integer
        For i As Integer = 0 To sourceImg.Width - 1
            For j As Integer = 0 To sourceImg.Height - 1
                pSourceColor = sourceImg.GetPixel(i,j)
                R = pSourceColor.R
                G = pSourceColor.G
                B = pSourceColor.B
                Select Case getMax(R,B)
                    Case "r"
                        pDestColor = Color.FromArgb(255,0)
                    Case "g"
                        pDestColor = Color.FromArgb(0,0)
                    Case Else
                        pDestColor = Color.FromArgb(0,255)
                End Select
                destImg.SetPixel(i,j,pDestColor)
            Next
        Next
        picDest.Image = destImg
    End Sub

    '自定义2
    Private Sub btnCustom2_Click(sender As Object,e As EventArgs) Handles btnCustom2.Click
        Dim pSourceColor As Color
        Dim pDestColor As Color

        Dim destImg As New Bitmap(sourceImg.Width,B)
                    Case "r"
                        pDestColor = Color.FromArgb(R,B)
                End Select
                destImg.SetPixel(i,pDestColor)
            Next
        Next
        picDest.Image = destImg
    End Sub

    '自定义3
    Private Sub btnCustom3_Click(sender As Object,e As EventArgs) Handles btnCustom3.Click
        Dim pSourceColor As Color
        Dim pDestColor As Color

        Dim destImg As New Bitmap(sourceImg.Width,R)
                    Case "g"
                        pDestColor = Color.FromArgb(G,G)
                    Case Else
                        pDestColor = Color.FromArgb(B,pDestColor)
            Next
        Next
        picDest.Image = destImg
    End Sub

运行效果：

由于.net平台下C#和vb.NET很相似，本文也可以为C#爱好者提供参考。

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