图片处理

using System;
using System.Drawing;
using System.Collections;
using System.ComponentModel;
using System.Windows.Forms;
using System.Data;

namespace Windows1
{
 /// <summary>
 /// Form1 的摘要说明。
 /// </summary>
 public class Form1 : System.Windows.Forms.Form
 {
  private System.Windows.Forms.Button button1;
  private System.Windows.Forms.Label label1;
  private System.Windows.Forms.Button button2;
  private System.Windows.Forms.PictureBox pictureBox1;
  private System.Windows.Forms.OpenFileDialog openFileDialog1;
  /// <summary>
  /// 必需的设计器变量。
  /// </summary>
  private System.ComponentModel.Container components = null;

  public Form1()
  {
   //
   // Windows 窗体设计器支持所必需的
   //
   InitializeComponent();

   //
   // TODO: 在 InitializeComponent 调用后添加任何构造函数代码
   //
  }

  /// <summary>
  /// 清理所有正在使用的资源。
  /// </summary>
  protected override void Dispose( bool disposing )
  {
   if( disposing )
   {
    if (components != null)
    {
     components.Dispose();
    }
   }
   base.Dispose( disposing );
  }

  #region Windows 窗体设计器生成的代码
  /// <summary>
  /// 设计器支持所需的方法 - 不要使用代码编辑器修改
  /// 此方法的内容。
  /// </summary>
  private void InitializeComponent()
  {
   this.button1 = new System.Windows.Forms.Button();
   this.label1 = new System.Windows.Forms.Label();
   this.button2 = new System.Windows.Forms.Button();
   this.pictureBox1 = new System.Windows.Forms.PictureBox();
   this.openFileDialog1 = new System.Windows.Forms.OpenFileDialog();
   this.SuspendLayout();
   //
   // button1
   //
   this.button1.Location = new System.Drawing.Point(16, 16);
   this.button1.Name = "button1";
   this.button1.TabIndex = 0;
   this.button1.Text = "打开图";
   this.button1.Click += new System.EventHandler(this.button1_Click);
   //
   // label1
   //
   this.label1.Location = new System.Drawing.Point(16, 200);
   this.label1.Name = "label1";
   this.label1.Size = new System.Drawing.Size(416, 120);
   this.label1.TabIndex = 1;
   //
   // button2
   //
   this.button2.Location = new System.Drawing.Point(176, 16);
   this.button2.Name = "button2";
   this.button2.TabIndex = 2;
   this.button2.Text = "生成";
   this.button2.Click += new System.EventHandler(this.button2_Click);
   //
   // pictureBox1
   //
   this.pictureBox1.Location = new System.Drawing.Point(8, 48);
   this.pictureBox1.Name = "pictureBox1";
   this.pictureBox1.Size = new System.Drawing.Size(424, 136);
   this.pictureBox1.TabIndex = 3;
   this.pictureBox1.TabStop = false;
   //
   // Form1
   //
   this.AutoScaleBaseSize = new System.Drawing.Size(6, 14);
   this.ClientSize = new System.Drawing.Size(472, 333);
   this.Controls.Add(this.pictureBox1);
   this.Controls.Add(this.button2);
   this.Controls.Add(this.label1);
   this.Controls.Add(this.button1);
   this.Name = "Form1";
   this.Text = "Form1";
   this.ResumeLayout(false);

  }
  #endregion

  /// <summary>
  /// 应用程序的主入口点。
  /// </summary>
  [STAThread]
  static void Main()
  {
   Application.Run(new Form1());
  }

  private void button1_Click(object sender, System.EventArgs e)
  {
   openFileDialog1.ShowDialog();
   pictureBox1.Image=System.Drawing.Bitmap.FromFile(openFileDialog1.FileName);
  }

  private void button2_Click(object sender, System.EventArgs e)
  {
  byte[] byte_img=pic_zero(openFileDialog1.FileName,100,150);
   label1.Text=byte_img.Length.ToString();
  }
/// <summary>
/// byte[] 图片另存
/// </summary>
/// <param name="sourcepath"></param>
/// <param name="kuan"></param>
/// <param name="gao"></param>
/// <returns></returns>
  public byte[]  pic_zero(string sourcepath,int kuan,int gao)    
  {
   byte[] byte_img=null;
   try
   {
    //生成流
    System.IO.Stream stream=new System.IO.MemoryStream();
    string originalFilename =sourcepath;     
    //生成的高质量图片名称     
    //从文件取得图片对象     
    System.Drawing.Image image = System.Drawing.Image.FromFile(originalFilename);     
    int iImgWidth = image.Width;     
    int iImgHeight = image.Height;     
//    int iScale = (iImgWidth / scale)>(iImgHeight/scale) ? (iImgWidth / scale) : (iImgHeight / scale);

    //取得图片大小     
    System.Drawing.Size size = new Size(kuan ,gao);     
    //新建一个bmp图片     
    System.Drawing.Image bitmap = new System.Drawing.Bitmap(size.Width,size.Height);

    //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;     
    //清空一下画布     
    g.Clear(Color.Blue);
    //在指定位置画图     
    g.DrawImage(image, new System.Drawing.Rectangle(0, 0, bitmap.Width, bitmap.Height),new System.Drawing.Rectangle(0, 0, image.Width,image.Height),System.Drawing.GraphicsUnit.Pixel);
    //保存高清晰度的缩略图     
//    bitmap.Save(strGoodFile, System.Drawing.Imaging.ImageFormat.Bmp);
     bitmap.Save(stream, System.Drawing.Imaging.ImageFormat.Jpeg);
    byte_img=ReadImage(stream);
    g.Dispose();     
    image.Dispose();
    bitmap.Dispose();
    
   }
   catch(Exception e)
   {
    MessageBox.Show("优化图片错误！"+e.ToString(),"错误");
   }
   return byte_img;
  }

/// <summary>
  /// 从给定的流中读取数据到一个字节数组中，并返回此数组。
  /// 如果给定的流不是一个图像格式的流，将报异常。
  /// 返回的字节数组中，将非BMP和JEPG格式的图像数据流转换为JEPG格式输出，以支持大多数应用。
  /// 适用于直接从数据库中读取的二进制图像流的处理。
  /// </summary>
  /// <param name="stream">给定的图像数据流。</param>
  /// <returns>从流中读取的数据。</returns>
  public static byte[] ReadImage(System.IO.Stream stream)
  {
   Image image = Image.FromStream(stream);
   byte[] myImage = null;

   if(image.RawFormat.Guid != System.Drawing.Imaging.ImageFormat.Jpeg.Guid && image.RawFormat.Guid != System.Drawing.Imaging.ImageFormat.Bmp.Guid)
   {
    System.IO.MemoryStream memStream = new System.IO.MemoryStream();
    image.Save(memStream, System.Drawing.Imaging.ImageFormat.Jpeg);
    myImage = memStream.GetBuffer();
    memStream.Close();
   }
   else
   {
    stream.Position = 0;
    myImage = new byte[stream.Length];
    stream.Read(myImage, 0, (int)stream.Length);
   }
   return myImage;
  }
 }
}