using System.Drawing
Image image;
image = Image.FromFile("d:\1.png");
Bitmap bitmap = new Bitmap(image);
bitmap.MakeTransparent( Color.White );
bitmap.Save("d:\2.png");
using System.Drawing
Image image;
image = Image.FromFile("d:\1.png");
Bitmap bitmap = new Bitmap(image);
bitmap.MakeTransparent( Color.White );
bitmap.Save("d:\2.png");