c#大规模图像转换器

我试图创建改变导入图像格式的程序，我不知道如何保存它，任何帮助将不胜感激——编辑;我试图保存每个文件导入到选定格式的特定文件夹我的代码;

    private void button1_Click(object sender, EventArgs e)
    {          
        if (dialog.ShowDialog() == DialogResult.OK)
        {
            foreach (String file in dialog.FileNames)
            {
                    listView1.Items.Add(System.IO.Path.GetFileNameWithoutExtension(file));
                    string filee = saveFileDialog1.FileName;

            }
        }
    }
    private void Form1_Load(object sender, EventArgs e)
    {
    }
    private void button2_Click(object sender, EventArgs e)
    {
       foreach (ListViewItem item in listView1.SelectedItems)
        {
            listView1.Items.Remove(item);
        }
    }
}

}

var image = System.Drawing.Image.FromFile(inputFilename);
image.Save(outputFileName, System.Drawing.Imaging.ImageFormat.Gif);