C#图片处理3种高级应用

using System;using System.Collections.Generic;using System.Text;using System.IO;using System.Drawing;using System.Drawing.Drawing2D;using System.Drawing.Imaging;namespace WuJian.Common{ public class Image {  #region 正方型裁剪并缩放  /// <summary>  /// 正方型裁剪  /// 以图片中心为轴心，截取正方型，然后等比缩放  /// 用于头像处理  /// </summary>  /// <remarks>吴剑 2012-08-08</remarks>  /// <param name="fromFile">原图Stream对象</param>  /// <param name="fileSaveUrl">缩略图存放地址</param>  /// <param name="side">指定的边长（正方型）</param>  /// <param name="quality">质量（范围0-100）</param>  public static void CutForSquare(System.IO.Stream fromFile, string fileSaveUrl, int side, int quality)  {   //创建目录   string dir = Path.GetDirectoryName(fileSaveUrl);   if (!Directory.Exists(dir))    Directory.CreateDirectory(dir);   //原始图片（获取原始图片创建对象，并使用流中嵌入的颜色管理信息）   System.Drawing.Image initImage = System.Drawing.Image.FromStream(fromFile, true);   //原图宽高均小于模版，不作处理，直接保存   if (initImage.Width <= side && initImage.Height <= side)   {    initImage.Save(fileSaveUrl, System.Drawing.Imaging.ImageFormat.Jpeg);   }   else   {    //原始图片的宽、高    int initWidth = initImage.Width;    int initHeight = initImage.Height;    //非正方型先裁剪为正方型    if (initWidth != initHeight)    {     //截图对象     System.Drawing.Image pickedImage = null;     System.Drawing.Graphics pickedG = null;     //宽大于高的横图     if (initWidth > initHeight)     {      //对象实例化      pickedImage = new System.Drawing.Bitmap(initHeight, initHeight);      pickedG = System.Drawing.Graphics.FromImage(pickedImage);      //设置质量      pickedG.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.HighQualityBicubic;      pickedG.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;      //定位      Rectangle fromR = new Rectangle((initWidth - initHeight) / 2, 0, initHeight, initHeight);      Rectangle toR = new Rectangle(0, 0, initHeight, initHeight);      //画图      pickedG.DrawImage(initImage, toR, fromR, System.Drawing.GraphicsUnit.Pixel);      //重置宽      initWidth = initHeight;     }     //高大于宽的竖图     else     {      //对象实例化      pickedImage = new System.Drawing.Bitmap(initWidth, initWidth);      pickedG = System.Drawing.Graphics.FromImage(pickedImage);      //设置质量      pickedG.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.HighQualityBicubic;      pickedG.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;      //定位      Rectangle fromR = new Rectangle(0, (initHeight - initWidth) / 2, initWidth, initWidth);      Rectangle toR = new Rectangle(0, 0, initWidth, initWidth);      //画图      pickedG.DrawImage(initImage, toR, fromR, System.Drawing.GraphicsUnit.Pixel);      //重置高      initHeight = initWidth;     }     //将截图对象赋给原图     initImage = (System.Drawing.Image)pickedImage.Clone();     //释放截图资源     pickedG.Dispose();     pickedImage.Dispose();    }    //缩略图对象    System.Drawing.Image resultImage = new System.Drawing.Bitmap(side, side);    System.Drawing.Graphics resultG = System.Drawing.Graphics.FromImage(resultImage);    //设置质量    resultG.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.HighQualityBicubic;    resultG.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;    //用指定背景色清空画布    resultG.Clear(Color.White);    //绘制缩略图    resultG.DrawImage(initImage, new System.Drawing.Rectangle(0, 0, side, side), new System.Drawing.Rectangle(0, 0, initWidth, initHeight), System.Drawing.GraphicsUnit.Pixel);    //关键质量控制    //获取系统编码类型数组,包含了jpeg,bmp,png,gif,tiff    ImageCodecInfo[] icis = ImageCodecInfo.GetImageEncoders();    ImageCodecInfo ici = null;    foreach (ImageCodecInfo i in icis)    {     if (i.MimeType == "image/jpeg" || i.MimeType == "image/bmp" || i.MimeType == "image/png" || i.MimeType == "image/gif")     {      ici = i;     }    }    EncoderParameters ep = new EncoderParameters(1);    ep.Param[0] = new EncoderParameter(System.Drawing.Imaging.Encoder.Quality, (long)quality);    //保存缩略图    resultImage.Save(fileSaveUrl, ici, ep);    //释放关键质量控制所用资源    ep.Dispose();    //释放缩略图资源    resultG.Dispose();    resultImage.Dispose();    //释放原始图片资源    initImage.Dispose();   }  }  #endregion  #region 自定义裁剪并缩放  /// <summary>  /// 指定长宽裁剪  /// 按模版比例最大范围的裁剪图片并缩放至模版尺寸  /// </summary>  /// <remarks>吴剑 2012-08-08</remarks>  /// <param name="fromFile">原图Stream对象</param>  /// <param name="fileSaveUrl">保存路径</param>  /// <param name="maxWidth">最大宽(单位:px)</param>  /// <param name="maxHeight">最大高(单位:px)</param>  /// <param name="quality">质量（范围0-100）</param>  public static void CutForCustom(System.IO.Stream fromFile, string fileSaveUrl, int maxWidth, int maxHeight, int quality)  {   //从文件获取原始图片，并使用流中嵌入的颜色管理信息   System.Drawing.Image initImage = System.Drawing.Image.FromStream(fromFile, true);   //原图宽高均小于模版，不作处理，直接保存   if (initImage.Width <= maxWidth && initImage.Height <= maxHeight)   {    initImage.Save(fileSaveUrl, System.Drawing.Imaging.ImageFormat.Jpeg);   }   else   {    //模版的宽高比例    double templateRate = (double)maxWidth / maxHeight;    //原图片的宽高比例    double initRate = (double)initImage.Width / initImage.Height;    //原图与模版比例相等，直接缩放    if (templateRate == initRate)    {     //按模版大小生成最终图片     System.Drawing.Image templateImage = new System.Drawing.Bitmap(maxWidth, maxHeight);     System.Drawing.Graphics templateG = System.Drawing.Graphics.FromImage(templateImage);     templateG.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.High;     templateG.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;     templateG.Clear(Color.White);     templateG.DrawImage(initImage, new System.Drawing.Rectangle(0, 0, maxWidth, maxHeight), new System.Drawing.Rectangle(0, 0, initImage.Width, initImage.Height), System.Drawing.GraphicsUnit.Pixel);     templateImage.Save(fileSaveUrl, System.Drawing.Imaging.ImageFormat.Jpeg);    }    //原图与模版比例不等，裁剪后缩放    else    {     //裁剪对象     System.Drawing.Image pickedImage = null;     System.Drawing.Graphics pickedG = null;     //定位     Rectangle fromR = new Rectangle(0, 0, 0, 0);//原图裁剪定位     Rectangle toR = new Rectangle(0, 0, 0, 0);//目标定位     //宽为标准进行裁剪     if (templateRate > initRate)     {      //裁剪对象实例化      pickedImage = new System.Drawing.Bitmap(initImage.Width, (int)System.Math.Floor(initImage.Width / templateRate));      pickedG = System.Drawing.Graphics.FromImage(pickedImage);      //裁剪源定位      fromR.X = 0;      fromR.Y = (int)System.Math.Floor((initImage.Height - initImage.Width / templateRate) / 2);      fromR.Width = initImage.Width;      fromR.Height = (int)System.Math.Floor(initImage.Width / templateRate);      //裁剪目标定位      toR.X = 0;      toR.Y = 0;      toR.Width = initImage.Width;      toR.Height = (int)System.Math.Floor(initImage.Width / templateRate);     }     //高为标准进行裁剪     else     {      pickedImage = new System.Drawing.Bitmap((int)System.Math.Floor(initImage.Height * templateRate), initImage.Height);      pickedG = System.Drawing.Graphics.FromImage(pickedImage);      fromR.X = (int)System.Math.Floor((initImage.Width - initImage.Height * templateRate) / 2);      fromR.Y = 0;      fromR.Width = (int)System.Math.Floor(initImage.Height * templateRate);      fromR.Height = initImage.Height;      toR.X = 0;      toR.Y = 0;      toR.Width = (int)System.Math.Floor(initImage.Height * templateRate);      toR.Height = initImage.Height;     }     //设置质量     pickedG.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.HighQualityBicubic;     pickedG.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;     //裁剪     pickedG.DrawImage(initImage, toR, fromR, System.Drawing.GraphicsUnit.Pixel);     //按模版大小生成最终图片     System.Drawing.Image templateImage = new System.Drawing.Bitmap(maxWidth, maxHeight);     System.Drawing.Graphics templateG = System.Drawing.Graphics.FromImage(templateImage);     templateG.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.High;     templateG.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;     templateG.Clear(Color.White);     templateG.DrawImage(pickedImage, new System.Drawing.Rectangle(0, 0, maxWidth, maxHeight), new System.Drawing.Rectangle(0, 0, pickedImage.Width, pickedImage.Height), System.Drawing.GraphicsUnit.Pixel);     //关键质量控制     //获取系统编码类型数组,包含了jpeg,bmp,png,gif,tiff     ImageCodecInfo[] icis = ImageCodecInfo.GetImageEncoders();     ImageCodecInfo ici = null;     foreach (ImageCodecInfo i in icis)     {      if (i.MimeType == "image/jpeg" || i.MimeType == "image/bmp" || i.MimeType == "image/png" || i.MimeType == "image/gif")      {       ici = i;      }     }     EncoderParameters ep = new EncoderParameters(1);     ep.Param[0] = new EncoderParameter(System.Drawing.Imaging.Encoder.Quality, (long)quality);     //保存缩略图     templateImage.Save(fileSaveUrl, ici, ep);     //templateImage.Save(fileSaveUrl, System.Drawing.Imaging.ImageFormat.Jpeg);     //释放资源     templateG.Dispose();     templateImage.Dispose();     pickedG.Dispose();     pickedImage.Dispose();    }   }   //释放资源   initImage.Dispose();  }  #endregion  #region 等比缩放  /// <summary>  /// 图片等比缩放  /// </summary>  /// <remarks>吴剑 2012-08-08</remarks>  /// <param name="fromFile">原图Stream对象</param>  /// <param name="savePath">缩略图存放地址</param>  /// <param name="targetWidth">指定的最大宽度</param>  /// <param name="targetHeight">指定的最大高度</param>  /// <param name="watermarkText">水印文字(为""表示不使用水印)</param>  /// <param name="watermarkImage">水印图片路径(为""表示不使用水印)</param>  public static void ZoomAuto(System.IO.Stream fromFile, string savePath, System.Double targetWidth, System.Double targetHeight, string watermarkText, string watermarkImage)  {   //创建目录   string dir = Path.GetDirectoryName(savePath);   if (!Directory.Exists(dir))    Directory.CreateDirectory(dir);   //原始图片（获取原始图片创建对象，并使用流中嵌入的颜色管理信息）   System.Drawing.Image initImage = System.Drawing.Image.FromStream(fromFile, true);   //原图宽高均小于模版，不作处理，直接保存   if (initImage.Width <= targetWidth && initImage.Height <= targetHeight)   {    //文字水印    if (watermarkText != "")    {     using (System.Drawing.Graphics gWater = System.Drawing.Graphics.FromImage(initImage))     {      System.Drawing.Font fontWater = new Font("黑体", 10);      System.Drawing.Brush brushWater = new SolidBrush(Color.White);      gWater.DrawString(watermarkText, fontWater, brushWater, 10, 10);      gWater.Dispose();     }    }    //透明图片水印    if (watermarkImage != "")    {     if (File.Exists(watermarkImage))     {      //获取水印图片      using (System.Drawing.Image wrImage = System.Drawing.Image.FromFile(watermarkImage))      {       //水印绘制条件：原始图片宽高均大于或等于水印图片       if (initImage.Width >= wrImage.Width && initImage.Height >= wrImage.Height)       {        Graphics gWater = Graphics.FromImage(initImage);        //透明属性        ImageAttributes imgAttributes = new ImageAttributes();        ColorMap colorMap = new ColorMap();        colorMap.OldColor = Color.FromArgb(255, 0, 255, 0);        colorMap.NewColor = Color.FromArgb(0, 0, 0, 0);        ColorMap[] remapTable = { colorMap };        imgAttributes.SetRemapTable(remapTable, ColorAdjustType.Bitmap);        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, 0.5f, 0.0f},//透明度:0.5         new float[] {0.0f, 0.0f, 0.0f, 0.0f, 1.0f}        };        ColorMatrix wmColorMatrix = new ColorMatrix(colorMatrixElements);        imgAttributes.SetColorMatrix(wmColorMatrix, ColorMatrixFlag.Default, ColorAdjustType.Bitmap);        gWater.DrawImage(wrImage, new Rectangle(initImage.Width - wrImage.Width, initImage.Height - wrImage.Height, wrImage.Width, wrImage.Height), 0, 0, wrImage.Width, wrImage.Height, GraphicsUnit.Pixel, imgAttributes);        gWater.Dispose();       }       wrImage.Dispose();      }     }    }    //保存    initImage.Save(savePath, System.Drawing.Imaging.ImageFormat.Jpeg);   }   else   {    //缩略图宽、高计算    double newWidth = initImage.Width;    double newHeight = initImage.Height;    //宽大于高或宽等于高（横图或正方）    if (initImage.Width > initImage.Height || initImage.Width == initImage.Height)    {     //如果宽大于模版     if (initImage.Width > targetWidth)     {      //宽按模版，高按比例缩放      newWidth = targetWidth;      newHeight = initImage.Height * (targetWidth / initImage.Width);     }    }    //高大于宽（竖图）    else    {     //如果高大于模版     if (initImage.Height > targetHeight)     {      //高按模版，宽按比例缩放      newHeight = targetHeight;      newWidth = initImage.Width * (targetHeight / initImage.Height);     }    }    //生成新图    //新建一个bmp图片    System.Drawing.Image newImage = new System.Drawing.Bitmap((int)newWidth, (int)newHeight);    //新建一个画板    System.Drawing.Graphics newG = System.Drawing.Graphics.FromImage(newImage);    //设置质量    newG.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.HighQualityBicubic;    newG.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;    //置背景色    newG.Clear(Color.White);    //画图    newG.DrawImage(initImage, new System.Drawing.Rectangle(0, 0, newImage.Width, newImage.Height), new System.Drawing.Rectangle(0, 0, initImage.Width, initImage.Height), System.Drawing.GraphicsUnit.Pixel);    //文字水印    if (watermarkText != "")    {     using (System.Drawing.Graphics gWater = System.Drawing.Graphics.FromImage(newImage))     {      System.Drawing.Font fontWater = new Font("宋体", 10);      System.Drawing.Brush brushWater = new SolidBrush(Color.White);      gWater.DrawString(watermarkText, fontWater, brushWater, 10, 10);      gWater.Dispose();     }    }    //透明图片水印    if (watermarkImage != "")    {     if (File.Exists(watermarkImage))     {      //获取水印图片      using (System.Drawing.Image wrImage = System.Drawing.Image.FromFile(watermarkImage))      {       //水印绘制条件：原始图片宽高均大于或等于水印图片       if (newImage.Width >= wrImage.Width && newImage.Height >= wrImage.Height)       {        Graphics gWater = Graphics.FromImage(newImage);        //透明属性        ImageAttributes imgAttributes = new ImageAttributes();        ColorMap colorMap = new ColorMap();        colorMap.OldColor = Color.FromArgb(255, 0, 255, 0);        colorMap.NewColor = Color.FromArgb(0, 0, 0, 0);        ColorMap[] remapTable = { colorMap };        imgAttributes.SetRemapTable(remapTable, ColorAdjustType.Bitmap);        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, 0.5f, 0.0f},//透明度:0.5         new float[] {0.0f, 0.0f, 0.0f, 0.0f, 1.0f}        };        ColorMatrix wmColorMatrix = new ColorMatrix(colorMatrixElements);        imgAttributes.SetColorMatrix(wmColorMatrix, ColorMatrixFlag.Default, ColorAdjustType.Bitmap);        gWater.DrawImage(wrImage, new Rectangle(newImage.Width - wrImage.Width, newImage.Height - wrImage.Height, wrImage.Width, wrImage.Height), 0, 0, wrImage.Width, wrImage.Height, GraphicsUnit.Pixel, imgAttributes);        gWater.Dispose();       }       wrImage.Dispose();      }     }    }    //保存缩略图    newImage.Save(savePath, System.Drawing.Imaging.ImageFormat.Jpeg);    //释放资源    newG.Dispose();    newImage.Dispose();    initImage.Dispose();   }  }  #endregion  #region 其它  /// <summary>  /// 判断文件类型是否为WEB格式图片  /// (注：JPG,GIF,BMP,PNG)  /// </summary>  /// <param name="contentType">HttpPostedFile.ContentType</param>  /// <returns></returns>  public static bool IsWebImage(string contentType)  {   if (contentType == "image/pjpeg" || contentType == "image/jpeg" || contentType == "image/gif" || contentType == "image/bmp" || contentType == "image/png")   {    return true;   }   else   {    return false;   }  }  #endregion }//end class}