C# 画像処理

using System.Drawing;
using System.IO;
using System.Windows.Forms;

public partial class Form1 : Form
{
    private Image _BmpCanvas;
    private Image _BmpImage;

    public Form1()
    {
        InitializeComponent();

        _BmpCanvas = new Bitmap(pictureBox1.Width, pictureBox1.Height, System.Drawing.Imaging.PixelFormat.Format32bppArgb);
        using (var g = Graphics.FromImage(_BmpCanvas))
        {
            g.Clear(Color.White);
        }
        _BmpImage = new Bitmap(new MemoryStream(File.ReadAllBytes(@"c:\test\1.png")));

        pictureBox1.Image = _BmpCanvas;
        this.pictureBox1.MouseMove += new MouseEventHandler(this.PictureBox1_MouseMove);
    }

    private void PictureBox1_MouseMove(object sender, MouseEventArgs e)
    {
        using (var g = Graphics.FromImage(_BmpCanvas))
        {
            g.Clear(Color.White);

            //変形用の平行四辺形の座標を指定し描画
            var img = _BmpImage;
            g.DrawImage(
                img,
                new [] {
                    new PointF(0, 0),                    
                    new PointF(img.Width, 0),
                    new PointF(e.Location.X - (img.Width / 2), e.Location.Y)
                }
            );
        }

        // PictureBox再描画
        pictureBox1.Invalidate();
    }
}