C#图片编辑类

using System;
using System.Drawing;
using System.IO;

/**//// <summary>
/// ImgEdit 的摘要说明
/// </summary>
public class ImgEdit
{
    public ImgEdit()
    {
        //
        // TODO: 在此处添加构造函数逻辑
        //
    }

    /**//// <summary>
    /// 图片水印
    /// </summary>
    /// <param name="ImgFile">原图文件地址</param>
    /// <param name="WaterImg">水印图片地址</param>
    /// <param name="sImgPath">水印图片保存地址</param>
    /// <param name="Alpha">水印透明度设置</param>
    /// <param name="iScale">水印图片在原图上的显示比例(水平)</param>
    /// <param name="intDistance">水印图片在原图上的边距确定,以图片的右边和下边为准,当设定的边距超过一定大小后参数会自动失效</param>
    public bool ImgWater(string ImgFile, string WaterImg, string sImgPath, float Alpha, float iScale, int intDistance)
    {
        try
        {
            //装载图片
            FileStream fs = new FileStream(ImgFile, FileMode.Open);
            BinaryReader br = new BinaryReader(fs);
            byte[] bytes = br.ReadBytes((int)fs.Length);
            br.Close();
            fs.Close();
            MemoryStream ms = new MemoryStream(bytes);

            System.Drawing.Image imgPhoto = System.Drawing.Image.FromStream(ms);
            int imgPhotoWidth = imgPhoto.Width;
            int imgPhotoHeight = imgPhoto.Height;

            System.Drawing.Image imgWatermark = new Bitmap(WaterImg);
            int imgWatermarkWidth = imgWatermark.Width;
            int imgWatermarkHeight = imgWatermark.Height;


            //计算水印图片尺寸
            decimal aScale = Convert.ToDecimal(iScale);
            decimal pScale = 0.05M;
            decimal MinScale = aScale - pScale;
            decimal MaxScale = aScale + pScale;

            //设置比例
            int imgWatermarkWidthNew = Convert.ToInt32(imgPhotoWidth * aScale);
            int imgWatermarkHeightNew = Convert.ToInt32((imgPhotoWidth * aScale / imgWatermarkWidth) * imgWatermarkHeight);


            //将原图画出来
            Bitmap bmPhoto = new Bitmap(imgPhotoWidth, imgPhotoHeight, System.Drawing.Imaging.PixelFormat.Format24bppRgb);
            bmPhoto.SetResolution(72, 72);
            Graphics gbmPhoto = Graphics.FromImage(bmPhoto);

            gbmPhoto.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.High;
            gbmPhoto.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;
            gbmPhoto.Clear(Color.White);
            gbmPhoto.DrawImage(imgPhoto, new Rectangle(0, 0, imgPhotoWidth, imgPhotoHeight), 0, 0, imgPhotoWidth, imgPhotoHeight, GraphicsUnit.Pixel);

            Bitmap bmWatermark = new Bitmap(bmPhoto);
            bmWatermark.SetResolution(imgPhoto.HorizontalResolution, imgPhoto.VerticalResolution);

            Graphics gWatermark = Graphics.FromImage(bmWatermark);

            //指定高质量显示水印图片质量
            gWatermark.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.High;
            gWatermark.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;
            System.Drawing.Imaging.ImageAttributes imageAttributes = new System.Drawing.Imaging.ImageAttributes();

            //设置两种颜色,达到合成效果
            System.Drawing.Imaging.ColorMap colorMap = new System.Drawing.Imaging.ColorMap();
            colorMap.OldColor = Color.FromArgb(255, 0, 255, 0);
            colorMap.NewColor = Color.FromArgb(0, 0, 0, 0);

            System.Drawing.Imaging.ColorMap[] remapTable = { colorMap };

            imageAttributes.SetRemapTable(remapTable, System.Drawing.Imaging.ColorAdjustType.Bitmap);

            //用矩阵设置水印图片透明度
            float[][] colorMatrixElements = { 
               new float[] {1.0f,  0.0f,  0.0f,  0.0f, 0.0f},
               new float[] {0.0f,  1.0f,  0.0f,  0.0f, 0.0f},
               new float[] {0.0f,  0.0f,  1.0f,  0.0f, 0.0f},
               new float[] {0.0f,  0.0f,  0.0f,  Alpha, 0.0f},
               new float[] {0.0f,  0.0f,  0.0f,  0.0f, 1.0f}
            };

            System.Drawing.Imaging.ColorMatrix wmColorMatrix = new System.Drawing.Imaging.ColorMatrix(colorMatrixElements);
            imageAttributes.SetColorMatrix(wmColorMatrix, System.Drawing.Imaging.ColorMatrixFlag.Default, System.Drawing.Imaging.ColorAdjustType.Bitmap);

            //确定水印边距
            int xPos = imgPhotoWidth - imgWatermarkWidthNew;
            int yPos = imgPhotoHeight - imgWatermarkHeightNew;
            int xPosOfWm = 0;
            int yPosOfWm = 0;

            if (xPos > intDistance)
                xPosOfWm = xPos - intDistance;
            else
                xPosOfWm = xPos;

            if (yPos > intDistance)
                yPosOfWm = yPos - intDistance;
            else
                yPosOfWm = yPos;

            gWatermark.DrawImage(imgWatermark, new Rectangle(xPosOfWm, yPosOfWm, imgWatermarkWidthNew, imgWatermarkHeightNew), 0, 0, imgWatermarkWidth, imgWatermarkHeight, GraphicsUnit.Pixel, imageAttributes);

            imgPhoto = bmWatermark;


            imgPhoto.Save(sImgPath, System.Drawing.Imaging.ImageFormat.Jpeg);

            //销毁对象
            gbmPhoto.Dispose();
            gWatermark.Dispose();

            imgPhoto.Dispose();
            imgWatermark.Dispose();

            return true;
        }
        catch (Exception ex)
        {
            return false;
        }
    }



    /**//// <summary>
    /// 文字水印
    /// </summary>
    /// <param name="ImgFile">原图文件地址</param>
    /// <param name="TextFont">水印文字</param>
    /// <param name="sImgPath">文字水印图片保存地址</param>
    /// <param name="Alpha">文字透明度 其数值的范围在0到255</param>
    /// <param name="widthFont">文字块在图片中所占宽度比例</param>
    /// <param name="hScale">高度位置</param>
    public bool TextWater(string ImgFile, string TextFont, string sImgPath, int Alpha, float widthFont, float hScale)
    {
        try
        {
            FileStream fs = new FileStream(ImgFile, FileMode.Open);
            BinaryReader br = new BinaryReader(fs);
            byte[] bytes = br.ReadBytes((int)fs.Length);
            br.Close();
            fs.Close();
            MemoryStream ms = new MemoryStream(bytes);

            System.Drawing.Image imgPhoto = System.Drawing.Image.FromStream(ms);
            int imgPhotoWidth = imgPhoto.Width;
            int imgPhotoHeight = imgPhoto.Height;

            Bitmap bmPhoto = new Bitmap(imgPhotoWidth, imgPhotoHeight, System.Drawing.Imaging.PixelFormat.Format24bppRgb);
            bmPhoto.SetResolution(72, 72);
            Graphics gbmPhoto = Graphics.FromImage(bmPhoto);
            gbmPhoto.Clear(Color.FromName("white"));//gif背景色
            gbmPhoto.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.High;
            gbmPhoto.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;
            gbmPhoto.DrawImage(imgPhoto, new Rectangle(0, 0, imgPhotoWidth, imgPhotoHeight), 0, 0, imgPhotoWidth, imgPhotoHeight, GraphicsUnit.Pixel);

            //建立字体大小的数组,循环找出适合图片的水印字体
            int[] sizes = new int[] { 1000, 800, 700, 650, 600, 560, 540, 500, 450, 400, 380, 360, 340, 320, 300, 280, 260, 240, 220, 200, 180, 160, 140, 120, 100, 80, 72, 64, 48, 32, 28, 26, 24, 20, 28, 16, 14, 12, 10, 8, 6, 4, 2 };
            System.Drawing.Font crFont = null;
            System.Drawing.SizeF crSize = new SizeF();
            for (int i = 0; i < 43; i++)
            {
                crFont = new Font("arial", sizes[i], FontStyle.Bold);
                crSize = gbmPhoto.MeasureString(TextFont, crFont);

                if ((ushort)crSize.Width < (ushort)imgPhotoWidth * widthFont)
                    break;
            }

            //设置水印字体的位置
            int yPixlesFromBottom = (int)(imgPhotoHeight * hScale);
            float yPosFromBottom = ((imgPhotoHeight - yPixlesFromBottom) - (crSize.Height / 2));
            float xCenterOfImg = (imgPhotoWidth * 1 / 2);

            System.Drawing.StringFormat StrFormat = new System.Drawing.StringFormat();
            StrFormat.Alignment = System.Drawing.StringAlignment.Center;

            //画两次制造透明效果
            System.Drawing.SolidBrush semiTransBrush2 = new System.Drawing.SolidBrush(Color.FromArgb(Alpha, 0, 0, 0));
            gbmPhoto.DrawString(TextFont, crFont, semiTransBrush2, new System.Drawing.PointF(xCenterOfImg + 1, yPosFromBottom + 1), StrFormat);

            System.Drawing.SolidBrush semiTransBrush = new System.Drawing.SolidBrush(Color.FromArgb(Alpha, 255, 255, 255));
            gbmPhoto.DrawString(TextFont, crFont, semiTransBrush, new System.Drawing.PointF(xCenterOfImg, yPosFromBottom), StrFormat);

            bmPhoto.Save(sImgPath, System.Drawing.Imaging.ImageFormat.Jpeg);

            gbmPhoto.Dispose();
            imgPhoto.Dispose();
            bmPhoto.Dispose();

            return true;
        }
        catch (Exception ex)
        {
            return false;
        }
    }


    /**//// <summary>
    /// 缩略图
    /// </summary>
    /// <param name="ImgFile">原图文件地址</param>
    /// <param name="sImgPath">缩略图保存地址</param>
    /// <param name="ResizeWidth">缩略图宽度</param>
    /// <param name="ResizeHeight">缩略图高度</param>
    /// <param name="BgColor">缩略图背景颜色,注意,背景颜色只能指定KnownColor中的值,如white,blue,red,green等</param>
    public bool ResizeImg(string ImgFile, string sImgPath, int ResizeWidth, int ResizeHeight, string BgColor)
    {
        try
        {
            FileStream fs = new FileStream(ImgFile, FileMode.Open);
            BinaryReader br = new BinaryReader(fs);
            byte[] bytes = br.ReadBytes((int)fs.Length);
            br.Close();
            fs.Close();
            MemoryStream ms = new MemoryStream(bytes);

            System.Drawing.Image imgPhoto = System.Drawing.Image.FromStream(ms);
            int imgPhotoWidth = imgPhoto.Width;
            int imgPhotoHeight = imgPhoto.Height;
            int StartX = 0;
            int StartY = 0;
            int NewWidth = imgPhotoWidth;
            int NewHeight = imgPhotoHeight;

            //计算缩放图片尺寸
            if (NewWidth > ResizeWidth)
            {
                NewWidth = ResizeWidth;
                NewHeight = Convert.ToInt32(imgPhotoHeight * Math.Round(Convert.ToDecimal(NewWidth) / Convert.ToDecimal(imgPhotoWidth), 10));
            }

            if (NewHeight > ResizeHeight)
            {
                NewHeight = ResizeHeight;
                NewWidth = Convert.ToInt32(imgPhotoWidth * Math.Round(Convert.ToDecimal(NewHeight) / Convert.ToDecimal(imgPhotoHeight), 10));
            }

            StartX = ResizeWidth - NewWidth;
            StartY = ResizeHeight - NewHeight;

            StartX = StartX > 0 ? StartX / 2 : 0;
            StartY = StartY > 0 ? StartY / 2 : 0;

            Bitmap bmPhoto = new Bitmap(ResizeWidth, ResizeHeight, System.Drawing.Imaging.PixelFormat.Format24bppRgb);
            bmPhoto.SetResolution(72, 72);
            Graphics gbmPhoto = Graphics.FromImage(bmPhoto);
            gbmPhoto.Clear(Color.FromName(BgColor));
            gbmPhoto.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.High;
            gbmPhoto.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;

            gbmPhoto.DrawImage(imgPhoto, new Rectangle(StartX, StartY, NewWidth, NewHeight), new Rectangle(0, 0, imgPhotoWidth, imgPhotoHeight), GraphicsUnit.Pixel);
            bmPhoto.Save(sImgPath, System.Drawing.Imaging.ImageFormat.Jpeg);

            imgPhoto.Dispose();
            gbmPhoto.Dispose();
            bmPhoto.Dispose();

            return true;
        }
        catch (Exception err)
        {
            return false;
        }
    }


    /**//// <summary>
    /// 图片剪切
    /// </summary>
    /// <param name="ImgFile">原图文件地址</param>
    /// <param name="sImgPath">缩略图保存地址</param>
    /// <param name="PointX">剪切起始点 X坐标</param>
    /// <param name="PointY">剪切起始点 Y坐标</param>
    /// <param name="CutWidth">剪切宽度</param>
    /// <param name="CutHeight">剪切高度</param>
    public bool CutImg(string ImgFile, string sImgPath, int PointX, int PointY, int CutWidth, int CutHeight)
    {
        try
        {
            FileStream fs = new FileStream(ImgFile, FileMode.Open);
            BinaryReader br = new BinaryReader(fs);
            byte[] bytes = br.ReadBytes((int)fs.Length);
            br.Close();
            fs.Close();
            MemoryStream ms = new MemoryStream(bytes);
            System.Drawing.Image imgPhoto = System.Drawing.Image.FromStream(ms);

            //System.Drawing.Image imgPhoto = System.Drawing.Image.FromFile(ImgFile);
            //此处只能用filestream，用 System.Drawing.Image则会报多过进程访问文件的错误，会锁定文件
            Bitmap bmPhoto = new Bitmap(CutWidth, CutHeight, System.Drawing.Imaging.PixelFormat.Format24bppRgb);
            bmPhoto.SetResolution(72, 72);
            Graphics gbmPhoto = Graphics.FromImage(bmPhoto);
            gbmPhoto.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.High;
            gbmPhoto.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;

            gbmPhoto.DrawImage(imgPhoto, new Rectangle(0, 0, CutWidth, CutHeight), new Rectangle(PointX, PointY, CutHeight, CutHeight), GraphicsUnit.Pixel);
            bmPhoto.Save(sImgPath, System.Drawing.Imaging.ImageFormat.Jpeg);

            imgPhoto.Dispose();
            gbmPhoto.Dispose();
            bmPhoto.Dispose();

            return true;
        }
        catch (Exception err)
        {
            return false;
        }
    }
}