C#写的图像处理代码存储

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.IO;
using System.Drawing;
using System.Drawing.Imaging;
 
namespace ConvertBKImg
{
    public class CImageLibrary
    {
        public enum ValidateImageResult { OK, InvalidFileSize, InvalidImageSize }
 
        //检查图片大小
        public static ValidateImageResult ValidateImage(string file, int MAX_FILE_SIZE, int MAX_WIDTH, int MAX_HEIGHT)
        {
 
            byte[] bs = File.ReadAllBytes(file);
 
            double size = (bs.Length / 1024);
 
            //大于50KB
            if (size > MAX_FILE_SIZE) 
                return ValidateImageResult.InvalidFileSize;
 
            Image img = Image.FromFile(file);
 
            if (img.Width > MAX_WIDTH || img.Height > MAX_HEIGHT) 
                return ValidateImageResult.InvalidImageSize;
 
            return ValidateImageResult.OK;
        }
 
        //彩图转灰图
        public static void ToGray(ref Image imgSource)
        {
            Color c = new Color();
            
            Bitmap b = new Bitmap(imgSource);
            int rr, gg, bb, cc;
            for (int i = 0; i < b.Width; i++)
            {
                for (int j = 0; j < b.Height; j++)
                {
                    c = b.GetPixel(i, j);
                    rr = c.R;
                    gg = c.G;
                    bb = c.B;
                    cc = (int)((rr + gg + bb) / 3);
                    if (cc < 0)
                        cc = 0;
                    if (cc > 255)
                        cc = 255;
                    //用FromArgb把整形转换成颜色值
                    Color c1 = Color.FromArgb(cc, cc, cc);
                    b.SetPixel(i, j, c1);
                }
                imgSource = b;
            }
        }
 
        //按宽度比例缩小图片
        public static Image GetOutputSizeImage(Image imgSource, int MAX_WIDTH)
        {
            Image imgOutput = imgSource;
 
            Size size = new Size(imgSource.Width, imgSource.Height);
 
            if (imgSource.Width <= 16 || imgSource.Height <= 16) 
                return imgSource; //16X16大小的图片不转换
 
            if (imgSource.Width > MAX_WIDTH || imgSource.Height > MAX_WIDTH)
            {
                double rate = MAX_WIDTH / (double)imgSource.Width;
                
                if (imgSource.Height * rate > MAX_WIDTH)
                    rate = MAX_WIDTH / (double)imgSource.Height;
                
                size.Width = Convert.ToInt32(imgSource.Width * rate);
                size.Height = Convert.ToInt32(imgSource.Height * rate);
                imgOutput = imgSource.GetThumbnailImage(size.Width, size.Height, null, IntPtr.Zero);
            }
 
            return imgOutput;
        }
 
        //按比例缩小图片
        public static Image GetOutputSizeImage(Image imgSource, Size outSize)
        {
            Image imgOutput = imgSource.GetThumbnailImage(outSize.Width, outSize.Height, null, IntPtr.Zero);
 
            return imgOutput;
 
        }
 
        /// <summary>
        /// 由图片文件转字节
        /// </summary>
        public static byte[] GetImageBytes(string imageFileName)
        {
            Image img = Image.FromFile(imageFileName);
            return GetImageBytes(img);
        }
 
        /// <summary>
        /// 图片转字节
        /// </summary>
        public static byte[] GetImageBytes(Image img)
        {
 
            if (img == null) return null;
 
            try
            {
                System.IO.MemoryStream ms = new MemoryStream();
                img.Save(ms, ImageFormat.Jpeg);
                byte[] bs = ms.ToArray();
                ms.Close();
 
                return bs;
            }
 
            catch { 
                return null; 
            }
        }
 
        /// <summary>
        /// 字节转图片
        /// </summary>
        public static Image FromBytes(byte[] bs)
        {
            if (bs == null) return null;
 
            try
            {
                MemoryStream ms = new MemoryStream(bs);
                Image returnImage = Image.FromStream(ms);
                ms.Close();
 
                return returnImage;
            }
 
            catch { 
                return null; 
            }
        }
 
        /// <summary>
        /// 将其它格式的图片转为JPG文件
        /// </summary>
        public static Image ToJPG(Image source)
        {
 
            //注意，先定义Bitmap类，否则会报A generic error occurred in GDI+
            Bitmap bmp = new Bitmap(source);
            MemoryStream ms = new MemoryStream();
            bmp.Save(ms, ImageFormat.Jpeg);
 
            return Bitmap.FromStream(ms);
        }
 
        /// <summary>
        /// 将其它格式的图片转为PNG文件
        /// </summary>
        public static Image ToPNG(Image source)
        {
 
            //注意，先定义Bitmap类，否则会报A generic error occurred in GDI+
            Bitmap bmp = new Bitmap(source);
            MemoryStream ms = new MemoryStream();
            bmp.Save(ms, ImageFormat.Png);
            return FromBytes(ms.ToArray());
        }
 
        //保存文件
        public static void SaveFile(string fileName, Image source)
        {
            source.Save(fileName, source.RawFormat);
        }
    }
}