c语言给图片加水印（c#图片文字提取代码）

本文实例为大家分享了C#.NET添加图片水印的方法，供大家参考，具体内容如下

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 using System; using System.Drawing; using System.Drawing.Drawing2D; using System.Drawing.Imaging; using System.IO; namespace Pub.Class { /// <summary> /// 添加水印类只支持添加图片水印 /// </summary> public class Watermark { #region 私有成员 private string modifyImagePath=null; private string drawedImagePath=null; private int rightSpace; private int bottoamSpace; private int lucencyPercent=70; private string outPath=null; #endregion #region 构造器 /// <summary> /// 构造函数 /// </summary> public Watermark() { } #endregion #region 属性 /// <summary> /// 获取或设置要修改的图像路径 /// </summary> public string ModifyImagePath { get{return this.modifyImagePath;} set{this.modifyImagePath=value;} } /// <summary> /// 获取或设置在画的图片路径(水印图片) /// </summary> public string DrawedImagePath { get{return this.drawedImagePath;} set{this.drawedImagePath=value;} } /// <summary> /// 获取或设置水印在修改图片中的右边距 /// </summary> public int RightSpace { get{return this.rightSpace;} set{this.rightSpace=value;} } /// <summary> /// 获取或设置水印在修改图片中距底部的高度 /// </summary> public int BottoamSpace { get{return this.bottoamSpace;} set{this.bottoamSpace=value;} } /// <summary> /// 获取或设置要绘制水印的透明度,注意是原来图片透明度的百分比 /// </summary> public int LucencyPercent { get{return this.lucencyPercent;} set { if(value>=0&&value<=100) this.lucencyPercent=value; } } /// <summary> /// 获取或设置要输出图像的路径 /// </summary> public string OutPath { get{return this.outPath;} set{this.outPath=value;} } #endregion #region 开始绘制水印 DrawImage /// <summary> /// 开始绘制水印 /// </summary> /// <example> /// <code> /// Watermark wm = new Watermark(); /// wm.DrawedImagePath= Server.MapPath("") + "/upfile/" + "backlogo.gif"; /// wm.ModifyImagePath=path; /// wm.RightSpace=184; /// wm.BottoamSpace=81; /// wm.LucencyPercent=50; /// wm.OutPath=Server.MapPath("") + "/upfile/" + fileName + "_new" + extension; /// wm.DrawImage(); /// /// //保存加水印过后的图片,删除原始图片 /// mFileName=fileName + "_new" + extension; /// if(File.Exists(path)) { File.Delete(path); } /// </code> /// </example> public void DrawImage() { Image modifyImage=null; Image drawedImage=null; Graphics g=null; try { modifyImage=Image.FromFile(this.ModifyImagePath);//建立图形对象 drawedImage=Image.FromFile(this.DrawedImagePath); g=Graphics.FromImage(modifyImage); int x=modifyImage.Width-this.rightSpace;//获取要绘制图形坐标 int y=modifyImage.Height-this.BottoamSpace; float[][] matrixItems ={//设置颜色矩阵 new float[] {1, 0, 0, 0, 0}, new float[] {0, 1, 0, 0, 0}, new float[] {0, 0, 1, 0, 0}, new float[] {0, 0, 0, (float)this.LucencyPercent/100f, 0}, new float[] {0, 0, 0, 0, 1}}; ColorMatrix colorMatrix = new ColorMatrix(matrixItems); ImageAttributes imgAttr=new ImageAttributes(); imgAttr.SetColorMatrix(colorMatrix,ColorMatrixFlag.Default,ColorAdjustType.Bitmap); g.DrawImage(//绘制阴影图像 drawedImage, new Rectangle(x,y,drawedImage.Width,drawedImage.Height), 0,0,drawedImage.Width,drawedImage.Height, GraphicsUnit.Pixel,imgAttr); string[] allowImageType={".jpg",".gif",".png",".bmp",".tiff",".wmf",".ico"};//保存文件 FileInfo file=new FileInfo(this.ModifyImagePath); ImageFormat imageType=ImageFormat.Gif; switch(file.Extension.ToLower()) { case ".jpg": imageType=ImageFormat.Jpeg; break; case ".gif": imageType=ImageFormat.Gif; break; case ".png": imageType=ImageFormat.Png; break; case ".bmp": imageType=ImageFormat.Bmp; break; case ".tif": imageType=ImageFormat.Tiff; break; case ".wmf": imageType=ImageFormat.Wmf; break; case ".ico": imageType=ImageFormat.Icon; break; default: break; } MemoryStream ms=new MemoryStream(); modifyImage.Save(ms,imageType); byte[] imgData=ms.ToArray(); modifyImage.Dispose(); drawedImage.Dispose(); g.Dispose(); FileStream fs=null; if(this.OutPath==null || this.OutPath=="") { File.Delete(this.ModifyImagePath); fs=new FileStream(this.ModifyImagePath,FileMode.Create,FileAccess.Write); } else { fs=new FileStream(this.OutPath,FileMode.Create,FileAccess.Write); } if(fs!=null) { fs.Write(imgData,0,imgData.Length); fs.Close(); } } finally { try { drawedImage.Dispose(); modifyImage.Dispose(); g.Dispose(); } catch{} } } #endregion } }