C#(.net)水印图片的生成(上）[转]

/*
*
*
* 此文分 上/下 合起来才能构成完整的一个类
* 使用说明：
* 　建议先定义一个WaterImage实例
* 　然后利用实例的属性，去匹配需要进行操作的参数
* 　然后定义一个WaterImageManage实例
* 　利用WaterImageManage实例进行DrawImage（），印图片水印
* 　DrawWords（）印文字水印
*
-*/

using System;
using System.Drawing;
using System.Drawing.Imaging;
using System.Drawing.Drawing2D;
using System.IO;

namespace ABC
{

    /// <summary>
    /// 图片位置
    /// </summary>
    public enum ImagePosition
    {
        LeftTop,        //左上
        LeftBottom,    //左下
        RightTop,       //右上
        RigthBottom, //右下
        TopMiddle,     //顶部居中
        BottomMiddle, //底部居中
        Center           //中心
    }

    /// <summary>
    /// 水印图片的操作管理 Design by Gary Gong From Demetersoft.com
    /// </summary>
    public class WaterImageManage
    {
        /// <summary>
        /// 生成一个新的水印图片制作实例
        /// </summary>
        public WaterImageManage()
        {
            //
            // TODO: Add constructor logic here
            //
        }

        /// <summary>
        /// 添加图片水印
        /// </summary>
        /// <param name="sourcePicture">源图片文件名</param>
        /// <param name="waterImage">水印图片文件名</param>
        /// <param name="alpha">透明度(0.1-1.0数值越小透明度越高)</param>
        /// <param name="position">位置</param>
        /// <param name="PicturePath" >图片的路径</param>
        /// <returns>返回生成于指定文件夹下的水印文件名</returns>
        public string DrawImage(string sourcePicture,
                                          string waterImage,
                                          float alpha,
                                          ImagePosition position,
                                          string PicturePath)
        {
            //
            // 判断参数是否有效
            //
            if (sourcePicture == string.Empty || waterImage == string.Empty || alpha == 0.0 || PicturePath == string.Empty)
            {
                return sourcePicture;
            }

            //
            // 源图片，水印图片全路径
            //
            string sourcePictureName = PicturePath + sourcePicture;
            string waterPictureName = PicturePath + waterImage;
            string fileSourceExtension = System.IO.Path.GetExtension(sourcePictureName).ToLower();
            string fileWaterExtension = System.IO.Path.GetExtension(waterPictureName).ToLower();
            //
            // 判断文件是否存在,以及类型是否正确
            //
            if (System.IO.File.Exists(sourcePictureName) == false ||
                System.IO.File.Exists(waterPictureName) == false || (
                fileSourceExtension != ".gif" &&
                fileSourceExtension != ".jpg" &&
                fileSourceExtension != ".png") || (
                fileWaterExtension != ".gif" &&
                fileWaterExtension != ".jpg" &&
                fileWaterExtension != ".png")
                )
            {
                return sourcePicture;
            }

            //
            // 目标图片名称及全路径
            //
            string targetImage = sourcePictureName.Replace(System.IO.Path.GetExtension(sourcePictureName), "") + "_1101.jpg";

            //
            // 将需要加上水印的图片装载到Image对象中
            //
            Image imgPhoto = Image.FromFile(sourcePictureName);
            //
            // 确定其长宽
            //
            int phWidth = imgPhoto.Width;
            int phHeight = imgPhoto.Height;

            //
            // 封装 GDI+ 位图，此位图由图形图像及其属性的像素数据组成。
            //
            Bitmap bmPhoto = new Bitmap(phWidth, phHeight, PixelFormat.Format24bppRgb);

            //
            // 设定分辨率
            //
            bmPhoto.SetResolution(imgPhoto.HorizontalResolution, imgPhoto.VerticalResolution);

            //
            // 定义一个绘图画面用来装载位图
            //
            Graphics grPhoto = Graphics.FromImage(bmPhoto);

            //
            //同样，由于水印是图片，我们也需要定义一个Image来装载它
            //
            Image imgWatermark = new Bitmap(waterPictureName);

            //
            // 获取水印图片的高度和宽度
            //
            int wmWidth = imgWatermark.Width;
            int wmHeight = imgWatermark.Height;

            //SmoothingMode：指定是否将平滑处理（消除锯齿）应用于直线、曲线和已填充区域的边缘。
            // 成员名称   说明
            // AntiAlias      指定消除锯齿的呈现。
            // Default        指定不消除锯齿。
            // HighQuality 指定高质量、低速度呈现。
            // HighSpeed   指定高速度、低质量呈现。
            // Invalid        指定一个无效模式。
            // None          指定不消除锯齿。
            grPhoto.SmoothingMode = SmoothingMode.AntiAlias;

            //
            // 第一次描绘，将我们的底图描绘在绘图画面上
            //
            grPhoto.DrawImage(imgPhoto,
                                        new Rectangle(0, 0, phWidth, phHeight),
                                        0,
                                        0,
                                        phWidth,
                                        phHeight,
                                        GraphicsUnit.Pixel);

            //
            // 与底图一样，我们需要一个位图来装载水印图片。并设定其分辨率
            //
            Bitmap bmWatermark = new Bitmap(bmPhoto);
            bmWatermark.SetResolution(imgPhoto.HorizontalResolution, imgPhoto.VerticalResolution);

            //
            // 继续，将水印图片装载到一个绘图画面grWatermark
            //
            Graphics grWatermark = Graphics.FromImage(bmWatermark);

            //
            //ImageAttributes 对象包含有关在呈现时如何操作位图和图元文件颜色的信息。
            //      
            ImageAttributes imageAttributes = new ImageAttributes();

            //
            //Colormap: 定义转换颜色的映射
            //
            ColorMap colorMap = new ColorMap();

            //
            //我的水印图被定义成拥有绿色背景色的图片被替换成透明
            //
            colorMap.OldColor = Color.FromArgb(255, 0, 255, 0);
            colorMap.NewColor = Color.FromArgb(0, 0, 0, 0);

            ColorMap[] remapTable = { colorMap };

            imageAttributes.SetRemapTable(remapTable, ColorAdjustType.Bitmap);

            float[][] colorMatrixElements = {
           new float[] {1.0f, 0.0f, 0.0f, 0.0f, 0.0f}, // red红色
           new float[] {0.0f, 1.0f, 0.0f, 0.0f, 0.0f}, //green绿色
           new float[] {0.0f, 0.0f, 1.0f, 0.0f, 0.0f}, //blue蓝色      
           new float[] {0.0f, 0.0f, 0.0f, alpha, 0.0f}, //透明度    
           new float[] {0.0f, 0.0f, 0.0f, 0.0f, 1.0f}};//

            // ColorMatrix:定义包含 RGBA 空间坐标的 5 x 5 矩阵。
            // ImageAttributes 类的若干方法通过使用颜色矩阵调整图像颜色。
            ColorMatrix wmColorMatrix = new ColorMatrix(colorMatrixElements);

            imageAttributes.SetColorMatrix(wmColorMatrix, ColorMatrixFlag.Default,
             ColorAdjustType.Bitmap);

            //
            //上面设置完颜色，下面开始设置位置
            //
            int xPosOfWm;
            int yPosOfWm;

            switch (position)
            {
                case ImagePosition.BottomMiddle:
                    xPosOfWm = (phWidth - wmWidth) / 2;
                    yPosOfWm = phHeight - wmHeight - 10;
                    break;
                case ImagePosition.Center:
                    xPosOfWm = (phWidth - wmWidth) / 2;
                    yPosOfWm = (phHeight - wmHeight) / 2;
                    break;
                case ImagePosition.LeftBottom:
                    xPosOfWm = 10;
                    yPosOfWm = phHeight - wmHeight - 10;
                    break;
                case ImagePosition.LeftTop:
                    xPosOfWm = 10;
                    yPosOfWm = 10;
                    break;
                case ImagePosition.RightTop:
                    xPosOfWm = phWidth - wmWidth - 10;
                    yPosOfWm = 10;
                    break;
                case ImagePosition.RigthBottom:
                    xPosOfWm = phWidth - wmWidth - 10;
                    yPosOfWm = phHeight - wmHeight - 10;
                    break;
                case ImagePosition.TopMiddle:
                    xPosOfWm = (phWidth - wmWidth) / 2;
                    yPosOfWm = 10;
                    break;
                default:
                    xPosOfWm = 10;
                    yPosOfWm = phHeight - wmHeight - 10;
                    break;
            }

            //
            // 第二次绘图，把水印印上去
            //
            grWatermark.DrawImage(imgWatermark,
             new Rectangle(xPosOfWm,
                                 yPosOfWm,
                                 wmWidth,
                                 wmHeight),
                                 0,
                                 0,
                                 wmWidth,
                                 wmHeight,
                                 GraphicsUnit.Pixel,
                                 imageAttributes);

            imgPhoto = bmWatermark;
            grPhoto.Dispose();
            grWatermark.Dispose();

            //
            // 保存文件到服务器的文件夹里面
            //
            //imgPhoto.Save(targetImage, ImageFormat.Jpeg);

 

       //提高图片质量

        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;
        image.Save(sDstFilePath, myImageCodecInfo, myEncoderParameters);
        myEncoderParameter.Dispose();
        myEncoderParameters.Dispose();

 

 

            imgPhoto.Dispose();
            imgWatermark.Dispose();
            return targetImage.Replace(PicturePath, "");
        }