C#图像提取


//提供一段代码，供ＬＺ参考
using System;
using System.Collections.Generic;
using System.Text;
using System.Drawing;
using System.Drawing.Imaging;
using System.Drawing.Drawing2D;
using System.IO;
using System.Windows.Forms;namespace LandaControl8_sqlserverImage
{
    /// <summary>
    /// 对图像进行一系列处理
    /// </summary>
    public class TreatImage
    {
        #region Bitmap转换byte[]数组
        /// <summary>
        /// Bitmap转换byte[]数组
        /// </summary>
        /// <param name="bmp"></param>
        /// <returns></returns>
        public static byte[] Bmptobyte(Bitmap bmp)
        {
            MemoryStream ms = new MemoryStream();
            bmp.Save(ms, ImageFormat.Jpeg);
            ms.Flush();
            byte[] buffer = ms.GetBuffer();
            ms.Close();
            return buffer;
        }
        #endregion        #region byte[]数组转换Bitmap
        /// <summary>
        /// byte[]数组转换Bitmap
        /// </summary>
        /// <param name="buffer"></param>
        /// <returns></returns>
        public static Bitmap bytetobmp(byte[] buffer)
        {
            MemoryStream ms = new MemoryStream();
            ms.Write(buffer, 0, buffer.Length);
            Bitmap bmp = new Bitmap(ms);
            ms.Close();
            return bmp;
        }
        #endregion        #region 选取本地图片
        /// <summary>
        /// 选取本地图片
        /// </summary>
        /// <param name="IMG"></param>
        /// <returns></returns>
        public static Bitmap LocalIMG(string IMG)
        {
            FileStream fs = new FileStream(IMG, FileMode.Open);
            Bitmap bmp = new Bitmap(fs);
            fs.Close();
            return bmp;
        }
        #endregion        #region 返回流状态图片
        /// <summary>
        /// 返回流状态图片
        /// </summary>
        /// <param name="Img"></param>
        /// <returns></returns>
        public static Bitmap ImgFromBase64(string Img)
        {
            Bitmap bmp;
            byte[] buffer = Convert.FromBase64String(Img);
            if (buffer.Length > 0)
            {
                MemoryStream ms = new MemoryStream();
                ms.Write(buffer, 0, buffer.Length);
                bmp = new Bitmap(ms);
                ms.Close();
                return bmp;
            }
            else
            {
                bmp = DefaultPic();
                return bmp;
            }
        }
        #endregion        #region 默认图片
        /// <summary>
        /// 默认图片
        /// </summary>
        /// <returns></returns>
        public static Bitmap DefaultPic()
        {
            FileStream fs = new FileStream(Application.StartupPath + @"\Goodr.jpg", FileMode.Open);
            Bitmap bmp = new Bitmap(fs);
            fs.Close();
            return bmp;
        }
        #endregion        private void numericUpDown2_ValueChanged(object sender, System.EventArgs e)
        {//更新图像显示   
            //this.button2.Refresh();
        }
        #endregion        #region 尺寸枚举
        public enum Dimensions
        {
            Width,
            Height
        }
        #endregion        #region 锚位置枚举
        public enum AnchorPosition
        {
            Top,
            Center,
            Bottom,
            Left,
            Right
        }
        #endregion        #region 按比例转换图像
        /// <summary>
        /// 返回按比价转换后的图像
        /// </summary>
        /// <param name="imgPhoto">指定图像</param>
        /// <param name="Size">指定尺寸</param>
        /// <param name="Dimension">按宽度或高度</param>
        /// <returns>返回按比价转换后的图像</returns>
        public static Image ConstrainProportions(Image imgPhoto, int Size, Dimensions Dimension)
        {
            int sourceWidth = imgPhoto.Width;
            int sourceHeight = imgPhoto.Height;
            int sourceX = 0;
            int sourceY = 0;
            int destX = 0;
            int destY = 0;
            float nPercent = 0;            switch (Dimension)
            {
                case Dimensions.Width:
                    nPercent = ((float)Size / (float)sourceWidth);
                    break;
                default:
                    nPercent = ((float)Size / (float)sourceHeight);
                    break;
            }            int destWidth = (int)(sourceWidth * nPercent);
            int destHeight = (int)(sourceHeight * nPercent);            Bitmap bmPhoto = new Bitmap(destWidth, destHeight, PixelFormat.Format24bppRgb);
            bmPhoto.SetResolution(imgPhoto.HorizontalResolution, imgPhoto.VerticalResolution);            Graphics grPhoto = Graphics.FromImage(bmPhoto);
            grPhoto.InterpolationMode = InterpolationMode.HighQualityBicubic;            grPhoto.DrawImage(imgPhoto,
            new Rectangle(destX, destY, destWidth, destHeight),
            new Rectangle(sourceX, sourceY, sourceWidth, sourceHeight),
            GraphicsUnit.Pixel);            grPhoto.Dispose();
            return bmPhoto;
        }
        #endregion        #region 按固定尺寸转换图像
        /// <summary>
        /// 返回按固定尺寸转换的图像
        /// </summary>
        /// <param name="imgPhoto">指定图像</param>
        /// <param name="Width">生成后图像的宽度</param>
        /// <param name="Height">生成后图像的高度</param>
        /// <returns>返回按固定尺寸转换的图像</returns>
        public static Image FixedSize(Image imgPhoto, int Width, int Height)
        {
            int sourceWidth = imgPhoto.Width;
            int sourceHeight = imgPhoto.Height;
            int sourceX = 0;
            int sourceY = 0;
            int destX = 0;
            int destY = 0;            float nPercent = 0;
            float nPercentW = 0;
            float nPercentH = 0;            nPercentW = ((float)Width / (float)sourceWidth);
            nPercentH = ((float)Height / (float)sourceHeight);            //if we have to pad the height pad both the top and the bottom
            //with the difference between the scaled height and the desired height
            if (nPercentH < nPercentW)
            {
                nPercent = nPercentH;
                destX = (int)((Width - (sourceWidth * nPercent)) / 2);
            }
            else
            {
                nPercent = nPercentW;
                destY = (int)((Height - (sourceHeight * nPercent)) / 2);
            }            int destWidth = (int)(sourceWidth * nPercent);
            int destHeight = (int)(sourceHeight * nPercent);            Bitmap bmPhoto = new Bitmap(Width, Height, PixelFormat.Format24bppRgb);
            bmPhoto.SetResolution(imgPhoto.HorizontalResolution, imgPhoto.VerticalResolution);            Graphics grPhoto = Graphics.FromImage(bmPhoto);
            grPhoto.Clear(Color.Red);
            grPhoto.InterpolationMode = InterpolationMode.HighQualityBicubic;            grPhoto.DrawImage(imgPhoto,
                new Rectangle(destX, destY, destWidth, destHeight),
                new Rectangle(sourceX, sourceY, sourceWidth, sourceHeight),
                GraphicsUnit.Pixel);            grPhoto.Dispose();
            return bmPhoto;
        }
        #endregion            }
}