各式各样的图片缩略水印静态类！

using System;
using System.Collections.Generic;
using System.Drawing;
using System.Drawing.Drawing2D;
using System.Drawing.Imaging;
using System.Text.RegularExpressions;
namespace Steam.Core
{
    public static class ImageDeal
    {
        /// <summary>
        /// 缩略图，按高度和宽度来缩略
        ///http://www.cnblogs.com/pooeo/
        /// </summary>
        /// <param name="image"></param>
        /// <param name="size"></param>
        /// <returns></returns>
        public static Image Scale(Image image, Size size)
        {
            return image.GetThumbnailImage(size.Width, size.Height, null, new IntPtr());
        }
        /// <summary>
        /// 缩略图，按倍数来缩略
        ///http://www.cnblogs.com/pooeo/
        /// </summary>
        /// <param name="image">原图</param>
        /// <param name="multiple">放大或缩小的倍数，负数表示缩小，正数表示放大</param>
        /// <returns></returns>
        public static Image Scale(Image image, Int32 multiple)
        {
            Int32 newWidth;
            Int32 newHeight;
            Int32 absMultiple = Math.Abs(multiple);
            if (multiple == 0)
            {
                return image.Clone() as Image;
            }
            if (multiple < 0)
            {
                newWidth = image.Width / absMultiple;
                newHeight = image.Height / absMultiple;
            }
            else
            {
                newWidth = image.Width * absMultiple;
                newHeight = image.Height * absMultiple;
            }
            return image.GetThumbnailImage(newWidth, newHeight, null, new IntPtr());
        }
        /// <summary>
        /// 固定宽度缩略
        ///http://www.cnblogs.com/pooeo/
        /// </summary>
        /// <param name="image"></param>
        /// <param name="width"></param>
        /// <returns></returns>
        public static Image ScaleFixWidth(Image image, Int32 width)
        {
            Int32 newWidth = width;
            Int32 newHeight;
            Double tempMultiple = (Double) newWidth / (Double) image.Width;
            newHeight = (Int32) (((Double) image.Height) * tempMultiple);
            Image newImage = new Bitmap(newWidth, newHeight);
            using (Graphics newGp = Graphics.FromImage(newImage))
            {
                newGp.CompositingQuality = CompositingQuality.HighQuality;
                //设置高质量插值法
                newGp.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.HighQualityBicubic;
                //设置高质量,低速度呈现平滑程度
                newGp.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;
                //清空画布并以透明背景色填充
                newGp.Clear(Color.Transparent);
                newGp.DrawImage(image, new Rectangle(0, 0, newWidth, newHeight));
            }
            return newImage;
        }
        /// <summary>
        /// 固定高度缩略
        ///http://www.cnblogs.com/pooeo/
        /// </summary>
        /// <param name="image"></param>
        /// <param name="height"></param>
        /// <returns></returns>
        public static Image ScaleFixHeight(Image image, Int32 height)
        {
            Int32 newWidth;
            Int32 newHeight = height;

            Double tempMultiple = (Double) newHeight / (Double) image.Height;
            newWidth = (Int32) (((Double) image.Width) * tempMultiple);
            Image newImage = new Bitmap(newWidth, newHeight);
            using (Graphics newGp = Graphics.FromImage(newImage))
            {
                newGp.CompositingQuality = CompositingQuality.HighQuality;
                //设置高质量插值法
                newGp.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.HighQualityBicubic;
                //设置高质量,低速度呈现平滑程度
                newGp.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;
                //清空画布并以透明背景色填充
                newGp.Clear(Color.Transparent);
                newGp.DrawImage(image, new Rectangle(0, 0, newWidth, newHeight));
            }
            return newImage;
        }
        /// <summary>
        /// 裁减缩略，根据固定的高度和宽度
        ///http://www.cnblogs.com/pooeo/
        /// </summary>
        /// <param name="image"></param>
        /// <param name="width"></param>
        /// <param name="heigth"></param>
        /// <returns></returns>
        public static Image ScaleCut(Image image, Int32 width, Int32 height)
        {
            int x = 0;
            int y = 0;
            int ow = image.Width;
            int oh = image.Height;
            if (width >= ow && height >= oh)
            {
                return image;
            }
            //如果结果要比原来的宽
            if (width > ow)
            {
                width = ow;
            }
            if (height > oh)
            {
                height = oh;
            }

            if ((double) image.Width / (double) image.Height > (double) width / (double) height)
            {
                oh = image.Height;
                ow = image.Height * width / height;
                y = 0;
                x = (image.Width - ow) / 2;
            }
            else
            {
                ow = image.Width;
                oh = image.Width * height / width;
                x = 0;
                y = (image.Height - oh) / 2;
            }
            Image newImage = new Bitmap(width, height);
            using (Graphics newGp = Graphics.FromImage(newImage))
            {
                newGp.CompositingQuality = CompositingQuality.HighQuality;
                //设置高质量插值法
                newGp.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.HighQualityBicubic;
                //设置高质量,低速度呈现平滑程度
                newGp.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;
                //清空画布并以透明背景色填充
                newGp.Clear(Color.Transparent);
                newGp.DrawImage(image, new Rectangle(0, 0, width, height),
                new Rectangle(x, y, ow, oh),
                GraphicsUnit.Pixel);
            }
            return newImage;
        }

        /// <summary>
        /// 生成缩略图
        ///http://www.cnblogs.com/pooeo/
        /// </summary>
        /// <param name="originalImagePath">源图路径（物理路径）</param>
        /// <param name="thumbnailPath">缩略图路径（物理路径）</param>
        /// <param name="width">缩略图宽度</param>
        /// <param name="height">缩略图高度</param>
        /// <param name="mode">生成缩略图的方式</param>    
        public static void MakeThumbnail(string originalImagePath, string thumbnailPath, int width, int height, string mode)
        {
            Image originalImage = Image.FromFile(originalImagePath);
            int towidth = width;
            int toheight = height;
            int x = 0;
            int y = 0;
            int ow = originalImage.Width;
            int oh = originalImage.Height;
            switch (mode)
            {
            case "HW"://指定高宽缩放（可能变形）                
                break;
            case "W"://指定宽，高按比例                    
                toheight = originalImage.Height * width / originalImage.Width;
                break;
            case "H"://指定高，宽按比例
                towidth = originalImage.Width * height / originalImage.Height;
                break;
            case "Cut"://指定高宽裁减（不变形）                
                if ((double) originalImage.Width / (double) originalImage.Height > (double) towidth / (double) toheight)
                {
                    oh = originalImage.Height;
                    ow = originalImage.Height * towidth / toheight;
                    y = 0;
                    x = (originalImage.Width - ow) / 2;
                }
                else
                {
                    ow = originalImage.Width;
                    oh = originalImage.Width * height / towidth;
                    x = 0;
                    y = (originalImage.Height - oh) / 2;
                }
                break;
            default:
                break;
            }
            //新建一个bmp图片
            Image bitmap = new System.Drawing.Bitmap(towidth, toheight);
            //新建一个画板
            Graphics g = System.Drawing.Graphics.FromImage(bitmap);
            //设置高质量插值法
            g.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.HighQualityBicubic;
            //设置高质量,低速度呈现平滑程度
            g.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;
            //清空画布并以透明背景色填充
            g.Clear(Color.Transparent);
            //在指定位置并且按指定大小绘制原图片的指定部分
            g.DrawImage(originalImage, new Rectangle(0, 0, towidth, toheight),
                new Rectangle(x, y, ow, oh),
                GraphicsUnit.Pixel);
            try
            {
                //以jpg格式保存缩略图
                bitmap.Save(thumbnailPath, System.Drawing.Imaging.ImageFormat.Jpeg);
            }
            catch (System.Exception e)
            {
                throw e;
            }
            finally
            {
                originalImage.Dispose();
                bitmap.Dispose();
                g.Dispose();
            }
        }
        /// <summary>
        /// 打水印，在某一点
        ///http://www.cnblogs.com/pooeo/
        /// </summary>
        /// <param name="image"></param>
        /// <param name="waterImagePath"></param>
        /// <param name="p"></param>
        public static void Makewater(Image image, String waterImagePath, Point p)
        {
            ImageDeal.Makewater(image, waterImagePath, p, ImagePosition.TopLeft);
        }
        public static void Makewater(Image image, String waterImagePath, Point p, ImagePosition imagePosition)
        {
            using (Image warterImage = Image.FromFile(waterImagePath))
            {
                using (Graphics newGp = Graphics.FromImage(image))
                {
                    newGp.CompositingQuality = CompositingQuality.HighQuality;
                    //设置高质量插值法
                    newGp.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.HighQualityBicubic;
                    //设置高质量,低速度呈现平滑程度
                    newGp.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;
                    switch (imagePosition)
                    {
                    case ImagePosition.BottomLeft:
                        p.Y = image.Height - warterImage.Height - p.Y;
                        break;
                    case ImagePosition.TopRigth:
                        p.X = image.Width - warterImage.Width - p.X;
                        break;
                    case ImagePosition.BottomRight:
                        p.Y = image.Height - warterImage.Height - p.Y;
                        p.X = image.Width - warterImage.Width - p.X;
                        break;
                    }
                    newGp.DrawImage(warterImage, new Rectangle(p, new Size(warterImage.Width, warterImage.Height)));
                }
            }
        }
        public static void Makewater(Image image, String waterStr, Font font, Brush brush, Point p)
        {
            ImageDeal.Makewater(image, waterStr, font, brush, p, ImagePosition.TopLeft);

        }
        public static void Makewater(Image image, String waterStr, Font font, Brush brush, Point p, ImagePosition imagePosition)
        {
            using (Graphics newGp = Graphics.FromImage(image))
            {
                Int32 stringWidth;
                Int32 stringHeight;
                stringHeight = (int) font.Size;
                stringWidth = (int) (((float) StringDeal.GetBitLength(waterStr) / (float) 2) * (font.Size + 1));
                newGp.CompositingQuality = CompositingQuality.HighQuality;
                //设置高质量插值法
                newGp.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.HighQualityBicubic;
                //设置高质量,低速度呈现平滑程度
                newGp.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;
                //文字抗锯齿
                newGp.TextRenderingHint = System.Drawing.Text.TextRenderingHint.AntiAlias;
                switch (imagePosition)
                {
                case ImagePosition.BottomLeft:
                    p.Y = image.Height - stringHeight - p.Y;
                    break;
                case ImagePosition.TopRigth:
                    p.X = image.Width - stringWidth - p.X;
                    break;
                case ImagePosition.BottomRight:
                    p.Y = image.Height - stringHeight - p.Y;
                    p.X = image.Width - stringWidth - p.X;
                    break;
                }
                newGp.DrawString(waterStr, font, brush, p);
            }
        }
        /// <summary>
        /// 高质量保存
        ///http://www.cnblogs.com/pooeo/       
        /// </summary>
        /// <param name="image"></param>
        /// <param name="path"></param>
        public static void SaveQuality(Image image, String path)
        {
            ImageCodecInfo myImageCodecInfo;
            Encoder myEncoder;
            EncoderParameter myEncoderParameter;
            EncoderParameters myEncoderParameters;
            myImageCodecInfo = ImageCodecInfo.GetImageEncoders()[0];
            myEncoder = Encoder.Quality;
            myEncoderParameters = new EncoderParameters(1);
            myEncoderParameter = new EncoderParameter(myEncoder, 100L); // 0-100
            myEncoderParameters.Param[0] = myEncoderParameter;
            try
            {
                image.Save(path, myImageCodecInfo, myEncoderParameters);
            }
            finally
            {
                myEncoderParameter.Dispose();
                myEncoderParameters.Dispose();
            }
        }
    }
    //当字符串中有中文时，一个中文的长度表示为2
    //如 StringDeal.GetBitLength("123")没有中文返回的长度是3
    //如 StringDeal.GetBigLength("123四")有中文返回的长度是5，如果直接用"123四".Length返回的是4
    public static class StringDeal
    {
        public static int GetBitLength(string waterStr)
        {
            Regex regex = new Regex("[\u4e00-\u9fa5]+");
            int length = waterStr.Length;

            for (int i = 0; i < waterStr.Length; i++)
            {
                if (regex.IsMatch(waterStr.Substring(i, 1)))
                {
                    length++;
                }
            }

            return length;
        }
    }
    public enum StringPosition
    {
        TopLeft,
        BottomLeft
    }
    public enum ImagePosition
    {
        TopLeft,
        BottomLeft,
        BottomRight,
        TopRigth
    }
}










【转自pooeo】