/*
* 给图片设置水印效果图的函数 * 可以在图片上添加自己的版权和LOGO图片的水印 * * 原作者:Joel Neubeck * * 本人在原作者的基础上进行了部分修改,并改为一个单独的函数 * 大家可以根据需要修改此代码 * 但请保留原作者信息. * * 星宿.net(zhuhee) * 修改于2006-6-14 * 
*/
using System;using System.Drawing;using System.Drawing.Imaging;using System.Drawing.Drawing2D;namespace WebWaterMark.Components{
/**//// <summary>
/// watermark 的摘要说明。
/// </summary> public class watermark { public watermark() { // // TODO: 在此处添加构造函数逻辑 // } /**//// <summary> /// 用于处理图片 /// 给图片加入水印 /// </summary> /// <param name="Copyright">需要写入的版权信息</param> /// <param name="MarkBmpPath">需要假如的logo图片</param> /// <param name="photoPath">需要处理的图片的路径</param> /// <param name="savePhotoPath">保存的图片路径</param> public void MakeWatermark(string Copyright,string MarkBmpPath,string photoPath,string savePhotoPath) { //创建一个image对象,即要被处理的图片 Image imgPhoto = Image.FromFile(photoPath); int phWidth = imgPhoto.Width; int phHeight = imgPhoto.Height; //创建原始图片大小的Bitmap Bitmap bmPhoto = new Bitmap(phWidth, phHeight, PixelFormat.Format24bppRgb); bmPhoto.SetResolution(imgPhoto.HorizontalResolution, imgPhoto.VerticalResolution); //将位图bmPhoto加载到Graphics对象 Graphics grPhoto = Graphics.FromImage(bmPhoto); //创建一个需要填充水银的Image对象 Image imgWatermark = new Bitmap(MarkBmpPath); int wmWidth = imgWatermark.Width; int wmHeight = imgWatermark.Height; //------------------------------------------------------------ //第一步,插入版权信息 //------------------------------------------------------------ //设置图象的成相质量 grPhoto.SmoothingMode = SmoothingMode.AntiAlias; //将原始图象绘制到grPhoto上 grPhoto.DrawImage( imgPhoto, // 要绘制的Image对象 new Rectangle(0, 0, phWidth, phHeight), // 绘制图象的位置和大小 0, // 要绘制的原图象部分的左上角的X坐标 0, // 要绘制的原图象部分的左上角的Y坐标 phWidth, // 要绘制的原图象的高度 phHeight, // 要绘制的原图象的宽度 GraphicsUnit.Pixel); // 源矩形的度量单位 //------------------------------------------------------- //字体大小放在一个数组中,最大字体为32. //感觉用处不大,可以自己再修改这里 //------------------------------------------------------- int[] sizes = new int[]{8,7,6,5,4}; Font crFont = null; SizeF crSize = new SizeF(); //循环测试数组中所定义的字体大小是否适合版权信息,如果合适就使用此种字体大小 for (int i=0 ;i<5; i++) { //设置字体类型,可以单独提出,作为参数 crFont = new Font("宋体", sizes[i], FontStyle.Bold); //测量此种字体大小 crSize = grPhoto.MeasureString(Copyright, crFont); if((ushort)crSize.Width < (ushort)phWidth) break; } //给底部保留%3的空间 int yPixlesFromBottom = (int)(phHeight *.03); //设置字体在图片中的位置 float yPosFromBottom = ((phHeight - yPixlesFromBottom)-(crSize.Height/2)); //float xCenterOfImg = (phWidth/2); float xCenterOfImg = (phWidth-(crSize.Width)/2); //设置字体居中 StringFormat StrFormat = new StringFormat(); StrFormat.Alignment = StringAlignment.Center; //设置绘制文本的颜色和纹理 (Alpha=153) SolidBrush semiTransBrush2 = new SolidBrush(Color.FromArgb(153, 0, 0, 0)); //将版权信息绘制到图象上 grPhoto.DrawString(Copyright, //版权信息 crFont, //字体 semiTransBrush2, //绘制文本的颜色及纹理 new PointF(xCenterOfImg+1,yPosFromBottom+1), //绘制文本的位置 StrFormat); //格式 //设置绘制文本的颜色和纹理 (Alpha=153) SolidBrush semiTransBrush = new SolidBrush(Color.FromArgb(153, 255, 255, 255)); //重新绘制版权信息,以让其具有阴影效果 //将文本向又下移动一个象素 grPhoto.DrawString(Copyright, //版权信息 crFont, //字体 semiTransBrush, //绘制文本的颜色及纹理 new PointF(xCenterOfImg,yPosFromBottom), //绘制文本的位置 StrFormat); //格式 //------------------------------------------------------------ //第二步,插入图片水印 //------------------------------------------------------------ //在原来修改过的bmPhoto上创建一个水银位图 Bitmap bmWatermark = new Bitmap(bmPhoto); bmWatermark.SetResolution(imgPhoto.HorizontalResolution, imgPhoto.VerticalResolution); //将位图bmWatermark加载到Graphics对象 Graphics grWatermark = Graphics.FromImage(bmWatermark); //To achieve a transulcent watermark we will apply (2) color //manipulations by defineing a ImageAttributes object and //seting (2) of its properties. ImageAttributes imageAttributes = new ImageAttributes(); //The first step in manipulating the watermark image is to replace //the background color with one that is trasparent (Alpha=0, R=0, G=0, B=0) //to do this we will use a Colormap and use this to define a RemapTable ColorMap colorMap = new ColorMap(); //My watermark was defined with a background of 100% Green this will //be the color we search for and replace with transparency colorMap.OldColor = Color.FromArgb(255, 0, 255, 0); colorMap.NewColor = Color.FromArgb(0, 0, 0, 0); ColorMap[] remapTable = {colorMap}; imageAttributes.SetRemapTable(remapTable, ColorAdjustType.Bitmap); //The second color manipulation is used to change the opacity of the //watermark. This is done by applying a 5x5 matrix that contains the //coordinates for the RGBA space. By setting the 3rd row and 3rd column //to 0.3f we achive a level of opacity float[][] colorMatrixElements = { new float[] {1.0f, 0.0f, 0.0f, 0.0f, 0.0f}, new float[] {0.0f, 1.0f, 0.0f, 0.0f, 0.0f}, new float[] {0.0f, 0.0f, 1.0f, 0.0f, 0.0f}, new float[] {0.0f, 0.0f, 0.0f, 0.3f, 0.0f}, new float[] {0.0f, 0.0f, 0.0f, 0.0f, 1.0f}}; ColorMatrix wmColorMatrix = new ColorMatrix(colorMatrixElements); imageAttributes.SetColorMatrix(wmColorMatrix, ColorMatrixFlag.Default, ColorAdjustType.Bitmap); //For this example we will place the watermark in the upper right //hand corner of the photograph. offset down 10 pixels and to the //left 10 pixles int xPosOfWm = ((phWidth - wmWidth)-10); int yPosOfWm = 10; grWatermark.DrawImage(imgWatermark, new Rectangle(xPosOfWm,yPosOfWm,wmWidth,wmHeight), //Set the detination Position 0, // x-coordinate of the portion of the source image to draw. 0, // y-coordinate of the portion of the source image to draw. wmWidth, // Watermark Width wmHeight, // Watermark Height GraphicsUnit.Pixel, // Unit of measurment imageAttributes); //ImageAttributes Object //Replace the original photgraphs bitmap with the new Bitmap imgPhoto = bmWatermark; grPhoto.Dispose(); grWatermark.Dispose(); //save new image to file system. imgPhoto.Save(savePhotoPath, ImageFormat.Jpeg); imgPhoto.Dispose(); imgWatermark.Dispose(); } }}源码这里下载:https://files.cnblogs.com/zhuhee/watermark_source.rar