C#给图片加文字和图片的水印

    /// <summary> 
    /// WaterMark 的摘要说明 
    /// </summary> 
    /// 图片加水印
    /// <param name="strCopyright">要加入的文字 </param>
    /// <param name="strMarkPath">水印图片路径 </param>
    /// <param name="strPhotoPath">要加水印的图片路径 </param>
    /// <param name="strSavePath">处理后的图片路径 </param>
    /// <param name="iMarkRightSpace">水印在修改图片中距右边的宽度 </param>
    /// <param name="iMarkButtomSpace">水印在修改图片中距底部的高度 </param>
    /// <param name="iDiaphaneity">水印图片的透明度 </param>
    /// <param name="iFontRightSpace">文字 </param>
    /// <param name="iFontButtomSpace">文字 </param>
    /// <param name="iFontDiaphaneity">文字 </param>
    /// <param name="bShowCopyright">是否显示文字 </param>
    /// <param name="bShowMarkImage">是否显示水印图片 </param>
    public class WaterMark
    {
        #region  param


        private string strCopyright, strMarkPath, strPhotoPath, strSavePath;
        private int iMarkRightSpace, iMarkButtomSpace, iDiaphaneity;
        private int iFontRightSpace = 0, iFontButtomSpace = 0, iFontDiaphaneity = 80;
        private int iFontSize = 10;
        private bool bShowCopyright = true, bShowMarkImage = true;


        #endregion


        #region WaterMark


        public WaterMark()
        {
            this.strCopyright = "";
            this.strMarkPath = null;
            this.strPhotoPath = null;
            this.strSavePath = null;
            this.iDiaphaneity = 70;
            this.iMarkRightSpace = 0;
            this.iMarkButtomSpace = 0;
        }


        /// <summary> 
        /// 主要用两样都加的
        /// </summary> 
        public WaterMark(string copyright, string markPath, string photoPath, string savePath)
        {
            this.strCopyright = copyright;
            this.strMarkPath = markPath;
            this.strPhotoPath = photoPath;
            this.strSavePath = savePath;
            this.iDiaphaneity = 70;
            this.iMarkRightSpace = 0;
            this.iMarkButtomSpace = 0;
        }


        #endregion


        #region property


        /// <summary> 
        /// 设置是否显示水印文字
        /// </summary> 
        public bool ShowCopyright
        {
            set { this.bShowCopyright = value; }
        }


        /// <summary> 
        /// 设置是否显示水印图片
        /// </summary> 
        public bool ShowMarkImage
        {
            set { this.bShowMarkImage = value; }
        }
        /// <summary> 
        /// 获取或设置要加入的文字
        /// </summary> 
        public string Copyright
        {
            set { this.strCopyright = value; }
        }


        /// <summary> 
        /// 获取或设置加水印后的图片路径
        /// </summary> 
        public string SavePath
        {
            get { return this.strSavePath; }
            set { this.strSavePath = value; }
        }


        /// <summary> 
        /// 获取或设置水印图片路径
        /// </summary> 
        public string MarkPath
        {
            get { return this.strMarkPath; }
            set { this.strMarkPath = value; }
        }


        /// <summary> 
        /// 获取或设置要加水印图片的路径
        /// </summary> 
        public string PhotoPath
        {
            get { return this.strPhotoPath; }
            set { this.strPhotoPath = value; }
        }


        /// <summary> 
        /// 设置水印图片的透明度
        /// </summary> 
        public int Diaphaneity
        {
            set
            {
                if (value > 0 && value <= 100)
                    this.iDiaphaneity = value;
            }
        }


        /// <summary> 
        /// 设置水印字体的透明度0-255
        /// </summary> 
        public int FontDiaphaneity
        {
            set
            {
                if (value >= 0 && value <= 255)
                    this.iFontDiaphaneity = value;
            }
        }


        /// <summary> 
        /// 设置水印图片在修改图片中距左边的高度
        /// </summary> 
        public int MarkRightSpace
        {
            set { this.iMarkRightSpace = value; }
        }


        /// <summary> 
        /// 设置水印图片在修改图片中距底部的高度
        /// </summary> 
        public int MarkButtomSpace
        {
            set { this.iMarkButtomSpace = value; }
        }


        /// <summary> 
        /// 设置水印字体在修改图片中距左边的距离
        /// </summary> 
        public int FontRightSpace
        {
            set { iFontRightSpace = value; }
        }


        /// <summary> 
        /// 设置水印字体在修改图片中距底部的高度
        /// </summary> 
        public int FontButtomSpace
        {
            set { iFontButtomSpace = value; }
        }


        #endregion




        /// <summary> 
        /// 生成水印图片
        /// </summary> 
        /// <returns> </returns> 
        public void createMarkPhoto()
        {
            Bitmap bmWatermark = null;
            FileStream fileStream = new FileStream(this.strPhotoPath, FileMode.Open, FileAccess.Read, FileShare.ReadWrite);
            Image gPhoto = Image.FromStream(fileStream);
            int PhotoWidth = gPhoto.Width;
            int PhotoHeight = gPhoto.Height;
            //Bitmap bitPhoto = new Bitmap(PhotoWidth, PhotoHeight, PixelFormat.Format24bppRgb);
            Bitmap bitPhoto = new Bitmap(PhotoWidth, PhotoHeight);
            bitPhoto.SetResolution(gPhoto.HorizontalResolution, gPhoto.VerticalResolution);


            try
            {
                if (bShowCopyright)
                {
                    Graphics grPhoto = Graphics.FromImage(bitPhoto);
                    //grPhoto.SmoothingMode = SmoothingMode.AntiAlias;//这句代码的作用是让合成模式为自动反锯齿,也就是所谓的"模糊"
                    grPhoto.DrawImage(gPhoto, new Rectangle(0, 0, PhotoWidth, PhotoHeight), 0, 0, PhotoWidth, PhotoHeight, GraphicsUnit.Pixel);


                    Font crFont = new Font("楷体", iFontSize, FontStyle.Bold);
                    SizeF crSize = grPhoto.MeasureString(strCopyright, crFont);


                    //设置字体在图片中的位置
                    float yPosFromBottom = PhotoHeight - iFontButtomSpace - (crSize.Height);


                    //float xCenterOfImg = (phWidth/2);
                    float xCenterOfImg = PhotoWidth - iFontRightSpace - (crSize.Width / 2);
                    //设置字体居中


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


                    //设置绘制文本的颜色和纹理 (Alpha=153)
                    SolidBrush semiTransBrush2 = new SolidBrush(Color.FromArgb(this.iFontDiaphaneity, 0, 0, 0));


                    //将版权信息绘制到图象上
                    grPhoto.DrawString(strCopyright, crFont, semiTransBrush2, new PointF(xCenterOfImg, yPosFromBottom), StrFormat);


                    gPhoto = bitPhoto;
                    grPhoto.Dispose();
                }


                if (bShowMarkImage)
                {
                    //创建一个需要填充水银的Image对象
                    Image imgWatermark = new Bitmap(strMarkPath);
                    int iMarkWidth = imgWatermark.Width;
                    int iMarkmHeight = imgWatermark.Height;


                    Graphics grWatermark = null;
                    if (bShowCopyright)
                    {
                        //在原来修改过的bmPhoto上创建一个水银位图
                        bmWatermark = new Bitmap(bitPhoto);
                        bmWatermark.SetResolution(gPhoto.HorizontalResolution, gPhoto.VerticalResolution);
                    }
                    else
                    {
                        bmWatermark = new Bitmap(gPhoto);
                    }


                    //将位图bmWatermark加载到Graphics对象
                    grWatermark = Graphics.FromImage(bmWatermark);
                    ImageAttributes imageAttributes = new ImageAttributes();


                    ColorMap colorMap = new ColorMap();


                    colorMap.OldColor = Color.FromArgb(255, 0, 255, 0);
                    colorMap.NewColor = Color.FromArgb(0, 0, 0, 0);


                    ColorMap[] remapTable = { colorMap };


                    imageAttributes.SetRemapTable(remapTable, ColorAdjustType.Bitmap);


                    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, (float)iDiaphaneity/100f, 0.0f},
                        new float[] {0.0f, 0.0f, 0.0f, 0.0f, 1.0f}};
                    ColorMatrix wmColorMatrix = new ColorMatrix(colorMatrixElements);
                    imageAttributes.SetColorMatrix(wmColorMatrix, ColorMatrixFlag.Default, ColorAdjustType.Bitmap);
                    grWatermark.DrawImage(imgWatermark, new Rectangle((PhotoWidth - iMarkRightSpace - (iMarkWidth / 2)), (PhotoHeight - iMarkButtomSpace - (iMarkmHeight / 2)), iMarkWidth, iMarkmHeight), 0, 0, iMarkWidth, iMarkmHeight, GraphicsUnit.Pixel, imageAttributes);


                    gPhoto = bmWatermark;
                    grWatermark.Dispose();
                    imgWatermark.Dispose();
                }
                //设置输出图片质量,默认输出是60%的清晰度
                EncoderParameter ep = new EncoderParameter(System.Drawing.Imaging.Encoder.Quality, 100L);
                EncoderParameters eps = new EncoderParameters(1);
                eps.Param[0] = ep;
                ImageCodecInfo ic = GetCodecInfo("image/jpeg");
                fileStream.Close();
                gPhoto.Save(strSavePath, ic, eps);
                bmWatermark.Dispose();
                bitPhoto.Dispose();
                gPhoto.Dispose();
                ep.Dispose();
                eps.Dispose();
            }
            finally
            {
                if (bitPhoto != null)
                    bitPhoto.Dispose();
                if (bmWatermark != null)
                    bmWatermark.Dispose();
                fileStream.Close();
                gPhoto.Dispose();
            }
        }


        private ImageCodecInfo GetCodecInfo(String mimeType)
        {
            ImageCodecInfo[] CodecInfo = ImageCodecInfo.GetImageEncoders();
            foreach (ImageCodecInfo ici in CodecInfo)
            {
                if (ici.MimeType == mimeType) return ici;
            }
            return null;
        }
    }
原文地址:https://www.cnblogs.com/blazeZzz/p/9558046.html