最全的C#图片处理帮助类ImageHelper.cs

方法介绍：

• 生成缩略图
• 图片水印处理方法
• 图片水印位置处理方法
• 文字水印处理方法
• 文字水印位置的方法
• 调整光暗
• 反色处理
• 浮雕处理
• 拉伸图片
• 滤色处理
• 左右翻转
• 上下翻转
• 压缩到指定尺寸
• 转换为黑白图片
• 获取图片中的各帧

代码如下：

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

namespace HelloCsharp.Utilities
{
public class ImageClass
{
public ImageClass()
{ }

#region 缩略图
///

/// 生成缩略图
///

///源图路径（物理路径） ///缩略图路径（物理路径） ///缩略图宽度 ///缩略图高度 ///生成缩略图的方式 public static void MakeThumbnail(string originalImagePath, string thumbnailPath, int width, int height, string mode)
{
System.Drawing.Image originalImage = System.Drawing.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
System.Drawing.Image bitmap = new System.Drawing.Bitmap(towidth, toheight);

//新建一个画板
System.Drawing.Graphics g = System.Drawing.Graphics.FromImage(bitmap);

//设置高质量插值法
g.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.High;

//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(System.Drawing.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 System.Drawing.Rectangle(0, 0, towidth, toheight), new System.Drawing.Rectangle(x, y, ow, oh), System.Drawing.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();
}
}
#endregion

#region 图片水印
///

/// 图片水印处理方法
///

///需要加载水印的图片路径（绝对路径） ///水印图片（绝对路径） ///水印位置（传送正确的代码） public static string ImageWatermark(string path, string waterpath, string location)
{
string kz_name = Path.GetExtension(path);
if (kz_name == ".jpg" || kz_name == ".bmp" || kz_name == ".jpeg")
{
DateTime time = DateTime.Now;
string filename = "" + time.Year.ToString() + time.Month.ToString() + time.Day.ToString() + time.Hour.ToString() + time.Minute.ToString() + time.Second.ToString() + time.Millisecond.ToString();
Image img = Bitmap.FromFile(path);
Image waterimg = Image.FromFile(waterpath);
Graphics g = Graphics.FromImage(img);
ArrayList loca = GetLocation(location, img, waterimg);
g.DrawImage(waterimg, new Rectangle(int.Parse(loca[0].ToString()), int.Parse(loca[1].ToString()), waterimg.Width, waterimg.Height));
waterimg.Dispose();
g.Dispose();
string newpath = Path.GetDirectoryName(path) + filename + kz_name;
img.Save(newpath);
img.Dispose();
File.Copy(newpath, path, true);
if (File.Exists(newpath))
{
File.Delete(newpath);
}
}
return path;
}

///

/// 图片水印位置处理方法
///

///水印位置 ///需要添加水印的图片 ///水印图片 private static ArrayList GetLocation(string location, Image img, Image waterimg)
{
ArrayList loca = new ArrayList();
int x = 0;
int y = 0;

if (location == "LT")
{
x = 10;
y = 10;
}
else if (location == "T")
{
x = img.Width / 2 - waterimg.Width / 2;
y = img.Height - waterimg.Height;
}
else if (location == "RT")
{
x = img.Width - waterimg.Width;
y = 10;
}
else if (location == "LC")
{
x = 10;
y = img.Height / 2 - waterimg.Height / 2;
}
else if (location == "C")
{
x = img.Width / 2 - waterimg.Width / 2;
y = img.Height / 2 - waterimg.Height / 2;
}
else if (location == "RC")
{
x = img.Width - waterimg.Width;
y = img.Height / 2 - waterimg.Height / 2;
}
else if (location == "LB")
{
x = 10;
y = img.Height - waterimg.Height;
}
else if (location == "B")
{
x = img.Width / 2 - waterimg.Width / 2;
y = img.Height - waterimg.Height;
}
else
{
x = img.Width - waterimg.Width;
y = img.Height - waterimg.Height;
}
loca.Add(x);
loca.Add(y);
return loca;
}
#endregion

#region 文字水印
///

/// 文字水印处理方法
///

///图片路径（绝对路径） ///字体大小 ///水印文字 ///颜色 ///水印位置 public static string LetterWatermark(string path, int size, string letter, Color color, string location)
{
#region

string kz_name = Path.GetExtension(path);
if (kz_name == ".jpg" || kz_name == ".bmp" || kz_name == ".jpeg")
{
DateTime time = DateTime.Now;
string filename = "" + time.Year.ToString() + time.Month.ToString() + time.Day.ToString() + time.Hour.ToString() + time.Minute.ToString() + time.Second.ToString() + time.Millisecond.ToString();
Image img = Bitmap.FromFile(path);
Graphics gs = Graphics.FromImage(img);
ArrayList loca = GetLocation(location, img, size, letter.Length);
Font font = new Font("宋体", size);
Brush br = new SolidBrush(color);
gs.DrawString(letter, font, br, float.Parse(loca[0].ToString()), float.Parse(loca[1].ToString()));
gs.Dispose();
string newpath = Path.GetDirectoryName(path) + filename + kz_name;
img.Save(newpath);
img.Dispose();
File.Copy(newpath, path, true);
if (File.Exists(newpath))
{
File.Delete(newpath);
}
}
return path;

#endregion
}

///

/// 文字水印位置的方法
///

///位置代码 ///图片对象 ///宽(当水印类型为文字时,传过来的就是字体的大小) ///高(当水印类型为文字时,传过来的就是字符的长度) private static ArrayList GetLocation(string location, Image img, int width, int height)
{
#region

ArrayList loca = new ArrayList();  //定义数组存储位置
float x = 10;
float y = 10;

if (location == "LT")
{
loca.Add(x);
loca.Add(y);
}
else if (location == "T")
{
x = img.Width / 2 - (width * height) / 2;
loca.Add(x);
loca.Add(y);
}
else if (location == "RT")
{
x = img.Width - width * height;
}
else if (location == "LC")
{
y = img.Height / 2;
}
else if (location == "C")
{
x = img.Width / 2 - (width * height) / 2;
y = img.Height / 2;
}
else if (location == "RC")
{
x = img.Width - height;
y = img.Height / 2;
}
else if (location == "LB")
{
y = img.Height - width - 5;
}
else if (location == "B")
{
x = img.Width / 2 - (width * height) / 2;
y = img.Height - width - 5;
}
else
{
x = img.Width - width * height;
y = img.Height - width - 5;
}
loca.Add(x);
loca.Add(y);
return loca;

#endregion
}
#endregion

#region 调整光暗
///

/// 调整光暗
///

///原始图片 ///原始图片的长度 ///原始图片的高度 ///增加或减少的光暗值 public Bitmap LDPic(Bitmap mybm, int width, int height, int val)
{
Bitmap bm = new Bitmap(width, height);//初始化一个记录经过处理后的图片对象
int x, y, resultR, resultG, resultB;//x、y是循环次数，后面三个是记录红绿蓝三个值的
Color pixel;
for (x = 0; x < width; x++)
{
for (y = 0; y < height; y++)
{
pixel = mybm.GetPixel(x, y);//获取当前像素的值
resultR = pixel.R + val;//检查红色值会不会超出[0, 255]
resultG = pixel.G + val;//检查绿色值会不会超出[0, 255]
resultB = pixel.B + val;//检查蓝色值会不会超出[0, 255]
bm.SetPixel(x, y, Color.FromArgb(resultR, resultG, resultB));//绘图
}
}
return bm;
}
#endregion

#region 反色处理
///

/// 反色处理
///

///原始图片 ///原始图片的长度 ///原始图片的高度 public Bitmap RePic(Bitmap mybm, int width, int height)
{
Bitmap bm = new Bitmap(width, height);//初始化一个记录处理后的图片的对象
int x, y, resultR, resultG, resultB;
Color pixel;
for (x = 0; x < width; x++)
{
for (y = 0; y < height; y++)
{
pixel = mybm.GetPixel(x, y);//获取当前坐标的像素值
resultR = 255 - pixel.R;//反红
resultG = 255 - pixel.G;//反绿
resultB = 255 - pixel.B;//反蓝
bm.SetPixel(x, y, Color.FromArgb(resultR, resultG, resultB));//绘图
}
}
return bm;
}
#endregion

#region 浮雕处理
///

/// 浮雕处理
///

///原始图片 ///原始图片的长度 ///原始图片的高度 public Bitmap FD(Bitmap oldBitmap, int Width, int Height)
{
Bitmap newBitmap = new Bitmap(Width, Height);
Color color1, color2;
for (int x = 0; x < Width - 1; x++)
{
for (int y = 0; y < Height - 1; y++) { int r = 0, g = 0, b = 0; color1 = oldBitmap.GetPixel(x, y); color2 = oldBitmap.GetPixel(x + 1, y + 1); r = Math.Abs(color1.R - color2.R + 128); g = Math.Abs(color1.G - color2.G + 128); b = Math.Abs(color1.B - color2.B + 128); if (r > 255) r = 255;
if (r < 0) r = 0; if (g > 255) g = 255;
if (g < 0) g = 0; if (b > 255) b = 255;
if (b < 0) b = 0;
newBitmap.SetPixel(x, y, Color.FromArgb(r, g, b));
}
}
return newBitmap;
}
#endregion

#region 拉伸图片
///

/// 拉伸图片
///

///原始图片 ///新的宽度 ///新的高度 public static Bitmap ResizeImage(Bitmap bmp, int newW, int newH)
{
try
{
Bitmap bap = new Bitmap(newW, newH);
Graphics g = Graphics.FromImage(bap);
g.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.HighQualityBicubic;
g.DrawImage(bap, new Rectangle(0, 0, newW, newH), new Rectangle(0, 0, bap.Width, bap.Height), GraphicsUnit.Pixel);
g.Dispose();
return bap;
}
catch
{
return null;
}
}
#endregion

#region 滤色处理
///

/// 滤色处理
///

///原始图片 ///原始图片的长度 ///原始图片的高度 public Bitmap FilPic(Bitmap mybm, int width, int height)
{
Bitmap bm = new Bitmap(width, height);//初始化一个记录滤色效果的图片对象
int x, y;
Color pixel;

for (x = 0; x < width; x++)
{
for (y = 0; y < height; y++)
{
pixel = mybm.GetPixel(x, y);//获取当前坐标的像素值
bm.SetPixel(x, y, Color.FromArgb(0, pixel.G, pixel.B));//绘图
}
}
return bm;
}
#endregion

#region 左右翻转
///

/// 左右翻转
///

///原始图片 ///原始图片的长度 ///原始图片的高度 public Bitmap RevPicLR(Bitmap mybm, int width, int height)
{
Bitmap bm = new Bitmap(width, height);
int x, y, z; //x,y是循环次数,z是用来记录像素点的x坐标的变化的
Color pixel;
for (y = height - 1; y >= 0; y--)
{
for (x = width - 1, z = 0; x >= 0; x--)
{
pixel = mybm.GetPixel(x, y);//获取当前像素的值
bm.SetPixel(z++, y, Color.FromArgb(pixel.R, pixel.G, pixel.B));//绘图
}
}
return bm;
}
#endregion

#region 上下翻转
///

/// 上下翻转
///

///原始图片 ///原始图片的长度 ///原始图片的高度 public Bitmap RevPicUD(Bitmap mybm, int width, int height)
{
Bitmap bm = new Bitmap(width, height);
int x, y, z;
Color pixel;
for (x = 0; x < width; x++) { for (y = height - 1, z = 0; y >= 0; y--)
{
pixel = mybm.GetPixel(x, y);//获取当前像素的值
bm.SetPixel(x, z++, Color.FromArgb(pixel.R, pixel.G, pixel.B));//绘图
}
}
return bm;
}
#endregion

#region 压缩图片
///

/// 压缩到指定尺寸
///

///原文件 ///新文件 public bool Compress(string oldfile, string newfile)
{
try
{
System.Drawing.Image img = System.Drawing.Image.FromFile(oldfile);
System.Drawing.Imaging.ImageFormat thisFormat = img.RawFormat;
Size newSize = new Size(100, 125);
Bitmap outBmp = new Bitmap(newSize.Width, newSize.Height);
Graphics g = Graphics.FromImage(outBmp);
g.CompositingQuality = CompositingQuality.HighQuality;
g.SmoothingMode = SmoothingMode.HighQuality;
g.InterpolationMode = InterpolationMode.HighQualityBicubic;
g.DrawImage(img, new Rectangle(0, 0, newSize.Width, newSize.Height), 0, 0, img.Width, img.Height, GraphicsUnit.Pixel);
g.Dispose();
EncoderParameters encoderParams = new EncoderParameters();
long[] quality = new long[1];
quality[0] = 100;
EncoderParameter encoderParam = new EncoderParameter(System.Drawing.Imaging.Encoder.Quality, quality);
encoderParams.Param[0] = encoderParam;
ImageCodecInfo[] arrayICI = ImageCodecInfo.GetImageEncoders();
ImageCodecInfo jpegICI = null;
for (int x = 0; x < arrayICI.Length; x++)
if (arrayICI[x].FormatDescription.Equals("JPEG"))
{
jpegICI = arrayICI[x]; //设置JPEG编码
break;
}
img.Dispose();
if (jpegICI != null) outBmp.Save(newfile, System.Drawing.Imaging.ImageFormat.Jpeg);
outBmp.Dispose();
return true;
}
catch
{
return false;
}
}
#endregion

#region 图片灰度化
public Color Gray(Color c)
{
int rgb = Convert.ToInt32((double)(((0.3 * c.R) + (0.59 * c.G)) + (0.11 * c.B)));
return Color.FromArgb(rgb, rgb, rgb);
}
#endregion

#region 转换为黑白图片
///

/// 转换为黑白图片
///

///要进行处理的图片 ///图片的长度 ///图片的高度 public Bitmap BWPic(Bitmap mybm, int width, int height)
{
Bitmap bm = new Bitmap(width, height);
int x, y, result; //x,y是循环次数，result是记录处理后的像素值
Color pixel;
for (x = 0; x < width; x++)
{
for (y = 0; y < height; y++)
{
pixel = mybm.GetPixel(x, y);//获取当前坐标的像素值
result = (pixel.R + pixel.G + pixel.B) / 3;//取红绿蓝三色的平均值
bm.SetPixel(x, y, Color.FromArgb(result, result, result));
}
}
return bm;
}
#endregion

#region 获取图片中的各帧
///

/// 获取图片中的各帧
///

///图片路径 ///保存路径 public void GetFrames(string pPath, string pSavedPath)
{
Image gif = Image.FromFile(pPath);
FrameDimension fd = new FrameDimension(gif.FrameDimensionsList[0]);
int count = gif.GetFrameCount(fd); //获取帧数(gif图片可能包含多帧，其它格式图片一般仅一帧)
for (int i = 0; i < count; i++)    //以Jpeg格式保存各帧
{
gif.SelectActiveFrame(fd, i);
gif.Save(pSavedPath + "\\frame_" + i + ".jpg", ImageFormat.Jpeg);
}
}
#endregion
}
}