Winform +OpenCvSharp更换证件照底色

 public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }
        private string selectedImagePath;
        Color backColor = Color.Empty;
        private void toolStrip1_ItemClicked(object sender, ToolStripItemClickedEventArgs e)
        {
            if ("tslSelectImage".Equals(e.ClickedItem.Name))
            {
                using OpenFileDialog openFileDialog = new OpenFileDialog();
                openFileDialog.Filter = "Image Files (*.bmp, *.jpg, *.png)|*.bmp;*.jpg;*.png";
                if (openFileDialog.ShowDialog() == DialogResult.OK)
                {
                    selectedImagePath = openFileDialog.FileName;
                    Image selectedImage = Image.FromFile(selectedImagePath);