C# 图片裁剪(剪切与缩小)的实现代码

///
///c# 剪切与缩小图片
///by http://www.jb200.com
///
public void CutToF(Stream stream)
{
Image initImage = Image.FromStream(stream, true);
if (initImage.Width <= 480 && initImage.Height <= 480)
{
initImage.Save("D://test.jpg", ImageFormat.Jpeg);
}
else
{
int initWidth = initImage.Width;
int initHeight = initImage.Height;
if (initWidth != initHeight)
{
Image pickedImage = null;
Graphics pickedG = null;
if (initWidth > initHeight)
{
pickedImage = new Bitmap(initHeight, initHeight);
pickedG = Graphics.FromImage(pickedImage);
pickedG.InterpolationMode = InterpolationMode.HighQualityBicubic;
pickedG.SmoothingMode = SmoothingMode.HighQuality;
Rectangle fromR = new Rectangle(0, 0, initHeight, initHeight);//(initWidth - initHeight) / 2
Rectangle toR = new Rectangle(0, 0, initHeight, initHeight);
pickedG.DrawImage(initImage, fromR);
pickedImage.Save("D://jpg//test2.jpg");
initWidth = initHeight;
}
initImage = (Image)pickedImage.Clone();
pickedG.Dispose();
pickedImage.Dispose();
initImage.Save("D://jpg//test1.jpg");

}
Image resultImage = new Bitmap(150, 150);
Graphics resultG = Graphics.FromImage(resultImage);
resultG.InterpolationMode = InterpolationMode.HighQualityBicubic;
resultG.SmoothingMode = SmoothingMode.HighQuality;
resultG.Clear(Color.White);
resultG.DrawImage(initImage, new Rectangle(0, 0, 100, 100), new Rectangle(0, 0, initWidth, initHeight), GraphicsUnit.Pixel);

ImageCodecInfo[] icis = ImageCodecInfo.GetImageEncoders();
ImageCodecInfo ici = null;
foreach (ImageCodecInfo item in icis)
{
if (item.MimeType == "image/jpeg" || item.MimeType == "image/bmp" || item.MimeType == "image/png" || item.MimeType =="image/gif")
{
ici = item;
}
}
EncoderParameters ep = new System.Drawing.Imaging.EncoderParameters(1);
ep.Param[0] = new System.Drawing.Imaging.EncoderParameter(System.Drawing.Imaging.Encoder.Quality, (long)100);
resultImage.Save("D://jpg//test.jpg", ici, ep);
ep.Dispose();
resultG.Dispose();
resultImage.Dispose();
initImage.Dispose();
}
}