C#图像处理（剪切、合成、缩略）

using System;
using System.Data;
using System.Configuration;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Drawing;
using System.Drawing.Drawing2D;
using System.Drawing.Imaging;


/// <summary>
///图片处理类
/// </summary>
public class Images
{
public Images()
{
//
//TODO: 在此处添加构造函数逻辑
//
}
  
    /// <summary>
    /// 剪切图片
    /// </summary>
    /// <param name="path_source">原始图片路径</param>
    /// <param name="path_save">目标图片路径</param>
    /// <param name="x">剪切位置的左上角x坐标</param>
    /// <param name="y">剪切位置的左上角y坐标</param>
    /// <param name="width">要剪切的宽度</param>
    /// <param name="height">要剪切的高度</param>
    public void Cut(string path_source, string path_save, int x, int y, int width, int height)
    {
        //加载底图
        Image img = Image.FromFile(path_source);
        int w = img.Width;
        int h = img.Height;
        //设置画布
        width = width >= w ? w : width;
        height = height >= h ? h : height;
        Bitmap map = new Bitmap(width, height);
        //绘图
        Graphics g = Graphics.FromImage(map);       
        g.DrawImage(img, 0, 0, new Rectangle(x,y, width, height), GraphicsUnit.Pixel);
        //保存
        map.Save(path_save);    

    }


    /// <summary>
    /// 生成缩略图
    /// </summary>
    /// <param name="path_source">原始图片路径</param>
    /// <param name="path_save">缩略图路径</param>
    /// <param name="times">缩略倍数</param>
    /// <param name="b">缩略或放大（true缩略）</param>
    public void Thumbnail(string path_source, string path_save, int times, bool b)
    {
        //加载底图
        Image img = Image.FromFile(path_source);
        int w = img.Width;
        int h = img.Height;
        //设置画布
        int width = 0;
        int height = 0;
        if (b)
        {
            width = w / times;
            height = h / times;
        }
        else
        {
            width = w * times;
            height = h * times;
        }
        Bitmap map = new Bitmap(width, height);
        //绘图
        Graphics g = Graphics.FromImage(map);
        g.DrawImage(img, 0, 0, width, height);
        //保存
        map.Save(path_save);

    }


    /// <summary>
    /// 图片合成
    /// </summary>
    /// <param name="p1">图片1</param>
    /// <param name="p2">图片2</param>
    /// <param name="path_save">新图片路径</param>
    public void Compound(string p1, string p2, string path_save)
    {
        //加载底图
        Image img1 = Image.FromFile(p1);
        Image img2 = Image.FromFile(p2);


        int w = img1.Width + img2.Width;
        int h = img1.Height > img2.Height ? img1.Height : img2.Height;
        
        //设置画布


        Bitmap map = new Bitmap(w, h);
        //绘图
        Graphics g = Graphics.FromImage(map);
        g.DrawImage(img1, 0, 0, new Rectangle(0, 0, img1.Width, img1.Height), GraphicsUnit.Pixel);
        g.DrawImage(img2, img1.Width, 0, new Rectangle(0, 0, img2.Width, img2.Height), GraphicsUnit.Pixel);
        //g.DrawImage(img, 0, 0, new Rectangle(0, 0, width, height), GraphicsUnit.Pixel);
        //保存
        map.Save(path_save);     
    }

}