图像裁切

public class Cutimg
{
/// <summary>
///
/// </summary>
/// <param name="pPath">原图地址</param>
/// <param name="filePath">存储图片地址</param>
/// <param name="pPartStartPointX">截取目标-x</param>
/// <param name="pPartStartPointY">截取目标-y</param>
/// <param name="pPartWidth">截取目标-宽度</param>
/// <param name="pPartHeight">截取目标-高度</param>
/// <param name="pOrigStartPointX">缩放图-x：0</param>
/// <param name="pOrigStartPointY">缩放图-y：0</param>
/// <param name="imageWidth">缩放图-宽度</param>
/// <param name="imageHeight">缩放图-高度</param>
/// <returns></returns>
public static bool SaveCutPic(string pPath, string filePath, int pPartStartPointX, int pPartStartPointY, int pPartWidth, int pPartHeight, int pOrigStartPointX, int pOrigStartPointY, int imageWidth, int imageHeight)
{
using (System.Drawing.Image originalImg = System.Drawing.Image.FromFile(pPath))
{
try
{
if (originalImg.Width == imageWidth && originalImg.Height == imageHeight)
{
return SaveCutPic(pPath, filePath, pPartStartPointX, pPartStartPointY, pPartWidth, pPartHeight,
pOrigStartPointX, pOrigStartPointY);

}

Bitmap thumimg = MakeThumbnail(originalImg, imageWidth, imageHeight);

Bitmap partImg = new Bitmap(pPartWidth, pPartHeight);

Graphics graphics = Graphics.FromImage(partImg);
Rectangle destRect = new Rectangle(new Point(pPartStartPointX, pPartStartPointY), new Size(pPartWidth, pPartHeight));//目标位置
Rectangle origRect = new Rectangle(new Point(pOrigStartPointX, pOrigStartPointY), new Size(pPartWidth, pPartHeight));//原图位置（默认从原图中截取的图片大小等于目标图片的大小）

///文字水印
Graphics G = Graphics.FromImage(partImg);
//Font f = new Font("Lucida Grande", 6);
//Brush b = new SolidBrush(Color.Gray);
G.Clear(Color.White);
// 指定高质量的双三次插值法。执行预筛选以确保高质量的收缩。此模式可产生质量最高的转换图像。
G.InterpolationMode = InterpolationMode.HighQualityBicubic;
// 指定高质量、低速度呈现。
G.SmoothingMode = SmoothingMode.HighQuality;

graphics.DrawImage(thumimg, destRect, origRect, GraphicsUnit.Pixel);
//G.DrawString("Xuanye", f, b, 0, 0);
G.Dispose();

originalImg.Dispose();
if (File.Exists(filePath))
{
File.SetAttributes(filePath, FileAttributes.Normal);
File.Delete(filePath);
}
if (!Directory.Exists(Path.GetDirectoryName(filePath)))
{
Directory.CreateDirectory(Path.GetDirectoryName(filePath));

}
partImg.Save(filePath, ImageFormat.Jpeg);

partImg.Dispose();
thumimg.Dispose();
}
catch
{
return false;
}
return true;
}
}

public static Bitmap MakeThumbnail(System.Drawing.Image fromImg, int width, int height)
{
Bitmap bmp = new Bitmap(width, height);
int ow = fromImg.Width;
int oh = fromImg.Height;

//新建一个画板
Graphics g = Graphics.FromImage(bmp);

//设置高质量插值法
g.InterpolationMode = InterpolationMode.High;
//设置高质量,低速度呈现平滑程度
g.SmoothingMode = SmoothingMode.Default;
//清空画布并以透明背景色填充
g.Clear(Color.White);

g.DrawImage(fromImg, new Rectangle(0, 0, width, height),
new Rectangle(0, 0, ow, oh),
GraphicsUnit.Pixel);

return bmp;

}

public static bool SaveCutPic(string pPath, string filePath, int pPartStartPointX, int pPartStartPointY, int pPartWidth, int pPartHeight, int pOrigStartPointX, int pOrigStartPointY)
{
using (System.Drawing.Image originalImg = System.Drawing.Image.FromFile(pPath))
{
try
{
Bitmap partImg = new Bitmap(pPartWidth, pPartHeight);
Graphics graphics = Graphics.FromImage(partImg);
Rectangle destRect = new Rectangle(new Point(pPartStartPointX, pPartStartPointY), new Size(pPartWidth, pPartHeight));//目标位置
Rectangle origRect = new Rectangle(new Point(pOrigStartPointX, pOrigStartPointY), new Size(pPartWidth, pPartHeight));//原图位置（默认从原图中截取的图片大小等于目标图片的大小）

///注释 文字水印
Graphics G = Graphics.FromImage(partImg);
//Font f = new Font("Lucida Grande", 6);
//Brush b = new SolidBrush(Color.Gray);
G.Clear(Color.White);
// 指定高质量的双三次插值法。执行预筛选以确保高质量的收缩。此模式可产生质量最高的转换图像。
G.InterpolationMode = InterpolationMode.HighQualityBicubic;
// 指定高质量、低速度呈现。
G.SmoothingMode = SmoothingMode.HighQuality;

graphics.DrawImage(originalImg, destRect, origRect, GraphicsUnit.Pixel);
//G.DrawString("Xuanye", f, b, 0, 0);
G.Dispose();

originalImg.Dispose();
if (File.Exists(filePath))
{
File.SetAttributes(filePath, FileAttributes.Normal);
File.Delete(filePath);
}
partImg.Save(filePath, ImageFormat.Jpeg);
partImg.Dispose();
}
catch
{
return false;
}
}
return true;
}
}