예제 #1
0
        /// <summary>
        /// 指定位置裁剪图片
        /// </summary>
        /// <param name="imgStream">图片流</param>
        /// <param name="x"></param>
        /// <param name="y"></param>
        /// <param name="x2"></param>
        /// <param name="y2"></param>
        /// <param name="quality">质量</param>
        /// <param name="imgExt">图片后缀</param>
        /// <returns></returns>
        public static MemoryStream CutImg(System.IO.Stream imgStream, int x, int y, int x2, int y2, int quality, string imgExt)
        {
            //原始图片(获取原始图片创建对象,并使用流中嵌入的颜色管理信息)
            System.Drawing.Image initImage = System.Drawing.Image.FromStream(imgStream, true);
            imgStream.Dispose();//释放资源
            int width  = x2 - x;
            int height = y2 - y;

            //截图对象
            System.Drawing.Image    pickedImage = new System.Drawing.Bitmap(width, height);
            System.Drawing.Graphics pickedG     = System.Drawing.Graphics.FromImage(pickedImage);
            //设置质量
            pickedG.InterpolationMode  = System.Drawing.Drawing2D.InterpolationMode.HighQualityBicubic;
            pickedG.SmoothingMode      = System.Drawing.Drawing2D.SmoothingMode.HighQuality;
            pickedG.CompositingQuality = System.Drawing.Drawing2D.CompositingQuality.HighQuality;
            //定位
            Rectangle fromR = new Rectangle(x, y, width, height);
            Rectangle toR   = new Rectangle(0, 0, width, height);

            //画图
            pickedG.DrawImage(initImage, toR, fromR, System.Drawing.GraphicsUnit.Pixel);
            //关键质量控制
            ImageCodecInfo    ici = SunImgFormat.GetImageCodecInfo(imgExt);
            EncoderParameters ep  = new EncoderParameters(1);

            ep.Param[0] = new EncoderParameter(System.Drawing.Imaging.Encoder.Quality, (long)quality);
            MemoryStream newMs = new MemoryStream();

            //保存缩略图
            pickedImage.Save(newMs, ici, ep);

            //释放关键质量控制所用资源
            ep.Dispose();
            //释放原始图片资源
            initImage.Dispose();
            //释放截图资源
            pickedG.Dispose();
            pickedImage.Dispose();
            return(newMs);
        }
예제 #2
0
        /// <summary>
        /// 压缩图片质量
        /// </summary>
        /// <param name="sourceImg">图片流</param>
        /// <param name="quality">图片质量</param>
        ///<param name="imgExt">图片后缀</param>
        /// <returns></returns>
        public static MemoryStream ImgReduce(System.IO.Stream sourceImg, int quality, string imgExt)
        {
            System.Drawing.Image iSource = System.Drawing.Image.FromStream(sourceImg);
            sourceImg.Dispose();
            MemoryStream newMs   = new MemoryStream();
            ImageFormat  tFormat = iSource.RawFormat;

            Bitmap ob = new Bitmap(iSource);;
            //以下代码为保存图片时,设置压缩质量
            EncoderParameters ep     = new EncoderParameters();
            EncoderParameter  eParam = new EncoderParameter(System.Drawing.Imaging.Encoder.Quality, quality);

            ep.Param[0] = eParam;
            try
            {
                ImageCodecInfo codeinfo = SunImgFormat.GetImageCodecInfo(imgExt);
                if (codeinfo != null)
                {
                    ob.Save(newMs, codeinfo, ep);
                }
                else
                {
                    ob.Save(newMs, tFormat);
                }
                return(newMs);
            }
            catch (Exception e)
            {
                throw new Exception(e.Message);
            }
            finally
            {
                iSource.Dispose();
                ob.Dispose();
                ep.Dispose();
            }
        }
예제 #3
0
        /// <summary>
        /// 按原图片比例获取缩略图
        /// </summary>
        /// <param name="sourceImg"></param>
        /// <param name="Width"></param>
        /// <param name="quality"></param>
        ///<param name="imgExt">图片后缀</param>
        /// <returns></returns>
        public static MemoryStream GetImgThumbnail(System.IO.Stream sourceImg, int Width, int quality, string imgExt)
        {
            System.Drawing.Image iSource = System.Drawing.Image.FromStream(sourceImg);
            sourceImg.Dispose();
            MemoryStream newMs = new MemoryStream();
            ImageFormat  tFormat = iSource.RawFormat;
            int          sW = 0, sH = 0;
            double       srate  = iSource.Width / (iSource.Height * 1.0);//原图宽高比例
            int          Height = Convert.ToInt32(Math.Floor(Width / srate));
            //按比例缩放
            Size tem_size = new Size(iSource.Width, iSource.Height);

            if (tem_size.Width > Height || tem_size.Width > Width)
            {
                if ((tem_size.Width * Height) > (tem_size.Height * Width))
                {
                    sW = Width;
                    sH = (Width * tem_size.Height) / tem_size.Width;
                }
                else
                {
                    sH = Height;
                    sW = (tem_size.Width * Height) / tem_size.Height;
                }
            }
            else
            {
                sW = tem_size.Width;
                sH = tem_size.Height;
            }
            Bitmap   ob = new Bitmap(Width, Height);
            Graphics g  = Graphics.FromImage(ob);

            g.Clear(Color.WhiteSmoke);
            g.CompositingQuality = System.Drawing.Drawing2D.CompositingQuality.HighQuality;
            g.SmoothingMode      = System.Drawing.Drawing2D.SmoothingMode.HighQuality;
            g.InterpolationMode  = System.Drawing.Drawing2D.InterpolationMode.HighQualityBicubic;
            g.DrawImage(iSource, new Rectangle((Width - sW) / 2 - 1, (Height - sH) / 2 - 1, sW + 2, sH + 1), 0, 0, iSource.Width, iSource.Height, GraphicsUnit.Pixel);
            g.Dispose();
            //以下代码为保存图片时,设置压缩质量
            EncoderParameters ep     = new EncoderParameters();
            EncoderParameter  eParam = new EncoderParameter(System.Drawing.Imaging.Encoder.Quality, quality);

            ep.Param[0] = eParam;
            try
            {
                ImageCodecInfo jpegICIinfo = SunImgFormat.GetImageCodecInfo(imgExt);
                if (jpegICIinfo != null)
                {
                    ob.Save(newMs, jpegICIinfo, ep);
                }
                else
                {
                    ob.Save(newMs, tFormat);
                }
                return(newMs);
            }
            catch (Exception e)
            {
                throw new Exception(e.Message);
            }
            finally
            {
                iSource.Dispose();
                ob.Dispose();
                ep.Dispose();
            }
        }
예제 #4
0
        /// <summary>
        /// 正方型裁剪
        /// 以图片中心为轴心,截取正方型,然后等比缩放
        /// 用于头像处理
        /// </summary>
        /// <param name="fromFile">原图Stream对象</param>
        /// <param name="side">指定的边长(正方型)</param>
        /// <param name="quality">质量(范围0-100)</param>
        ///<param name="imgExt">图片后缀</param>
        public static MemoryStream CutForSquare(System.IO.Stream fromFile, int side, int quality, string imgExt)
        {
            //原始图片(获取原始图片创建对象,并使用流中嵌入的颜色管理信息)
            System.Drawing.Image initImage = System.Drawing.Image.FromStream(fromFile, true);
            fromFile.Dispose();//释放资源
            //原始图片的宽、高
            int initWidth  = initImage.Width;
            int initHeight = initImage.Height;

            //非正方型先裁剪为正方型
            if (initWidth != initHeight)
            {
                //截图对象
                System.Drawing.Image    pickedImage = null;
                System.Drawing.Graphics pickedG     = null;

                //宽大于高的横图
                if (initWidth > initHeight)
                {
                    //对象实例化
                    pickedImage = new System.Drawing.Bitmap(initHeight, initHeight);
                    pickedG     = System.Drawing.Graphics.FromImage(pickedImage);
                    //设置质量
                    pickedG.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.HighQualityBicubic;
                    pickedG.SmoothingMode     = System.Drawing.Drawing2D.SmoothingMode.HighQuality;
                    //定位
                    Rectangle fromR = new Rectangle((initWidth - initHeight) / 2, 0, initHeight, initHeight);
                    Rectangle toR   = new Rectangle(0, 0, initHeight, initHeight);
                    //画图
                    pickedG.DrawImage(initImage, toR, fromR, System.Drawing.GraphicsUnit.Pixel);
                    //重置宽
                    initWidth = initHeight;
                }
                //高大于宽的竖图
                else
                {
                    //对象实例化
                    pickedImage = new System.Drawing.Bitmap(initWidth, initWidth);
                    pickedG     = System.Drawing.Graphics.FromImage(pickedImage);
                    //设置质量
                    pickedG.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.HighQualityBicubic;
                    pickedG.SmoothingMode     = System.Drawing.Drawing2D.SmoothingMode.HighQuality;
                    //定位
                    Rectangle fromR = new Rectangle(0, (initHeight - initWidth) / 2, initWidth, initWidth);
                    Rectangle toR   = new Rectangle(0, 0, initWidth, initWidth);
                    //画图
                    pickedG.DrawImage(initImage, toR, fromR, System.Drawing.GraphicsUnit.Pixel);
                    //重置高
                    initHeight = initWidth;
                }

                //将截图对象赋给原图
                initImage = (System.Drawing.Image)pickedImage.Clone();
                //释放截图资源
                pickedG.Dispose();
                pickedImage.Dispose();
            }

            //缩略图对象
            System.Drawing.Image    resultImage = new System.Drawing.Bitmap(side, side);
            System.Drawing.Graphics resultG     = System.Drawing.Graphics.FromImage(resultImage);
            //设置质量
            resultG.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.HighQualityBicubic;
            resultG.SmoothingMode     = System.Drawing.Drawing2D.SmoothingMode.HighQuality;
            //用指定背景色清空画布
            resultG.Clear(Color.White);
            //绘制缩略图
            resultG.DrawImage(initImage, new System.Drawing.Rectangle(0, 0, side, side), new System.Drawing.Rectangle(0, 0, initWidth, initHeight), System.Drawing.GraphicsUnit.Pixel);

            //关键质量控制
            ImageCodecInfo    ici = SunImgFormat.GetImageCodecInfo(imgExt);
            EncoderParameters ep  = new EncoderParameters(1);

            ep.Param[0] = new EncoderParameter(System.Drawing.Imaging.Encoder.Quality, (long)quality);
            MemoryStream newMs = new MemoryStream();

            //保存缩略图
            resultImage.Save(newMs, ici, ep);

            //释放关键质量控制所用资源
            ep.Dispose();

            //释放缩略图资源
            resultG.Dispose();
            resultImage.Dispose();

            //释放原始图片资源
            initImage.Dispose();
            return(newMs);
        }
예제 #5
0
        /// <summary>
        /// 指定长宽裁剪缩放
        /// 按模版比例最大范围的裁剪图片并缩放至模版尺寸
        /// </summary>
        /// <param name="fromFile">原图Stream对象</param>
        /// <param name="maxWidth">最大宽(单位:px)</param>
        /// <param name="maxHeight">最大高(单位:px)</param>
        /// <param name="quality">质量(范围0-100)</param>
        ///<param name="imgExt">图片后缀</param>
        public static MemoryStream CutForCustom(System.IO.Stream fromFile, int maxWidth, int maxHeight, int quality, string imgExt)
        {
            //从文件获取原始图片,并使用流中嵌入的颜色管理信息
            System.Drawing.Image initImage = System.Drawing.Image.FromStream(fromFile, true);
            ImageFormat          tFormat   = initImage.RawFormat;
            MemoryStream         newMS     = new MemoryStream();

            fromFile.Dispose();//释放资源
            //模版的宽高比例
            double templateRate = (double)maxWidth / maxHeight;
            //原图片的宽高比例
            double initRate = (double)initImage.Width / initImage.Height;

            //原图与模版比例相等,直接缩放
            if (templateRate == initRate)
            {
                //按模版大小生成最终图片
                System.Drawing.Image    templateImage = new System.Drawing.Bitmap(maxWidth, maxHeight);
                System.Drawing.Graphics templateG     = System.Drawing.Graphics.FromImage(templateImage);
                templateG.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.High;
                templateG.SmoothingMode     = System.Drawing.Drawing2D.SmoothingMode.HighQuality;
                templateG.Clear(Color.White);
                templateG.DrawImage(initImage, new System.Drawing.Rectangle(0, 0, maxWidth, maxHeight), new System.Drawing.Rectangle(0, 0, initImage.Width, initImage.Height), System.Drawing.GraphicsUnit.Pixel);
                templateImage.Save(newMS, tFormat);
                return(newMS);
            }
            //原图与模版比例不等,裁剪后缩放
            else
            {
                //裁剪对象
                System.Drawing.Image    pickedImage = null;
                System.Drawing.Graphics pickedG     = null;

                //定位
                Rectangle fromR = new Rectangle(0, 0, 0, 0); //原图裁剪定位
                Rectangle toR   = new Rectangle(0, 0, 0, 0); //目标定位

                //宽为标准进行裁剪
                if (templateRate > initRate)
                {
                    //裁剪对象实例化
                    pickedImage = new System.Drawing.Bitmap(initImage.Width, (int)System.Math.Floor(initImage.Width / templateRate));
                    pickedG     = System.Drawing.Graphics.FromImage(pickedImage);

                    //裁剪源定位
                    fromR.X      = 0;
                    fromR.Y      = (int)System.Math.Floor((initImage.Height - initImage.Width / templateRate) / 2);
                    fromR.Width  = initImage.Width;
                    fromR.Height = (int)System.Math.Floor(initImage.Width / templateRate);

                    //裁剪目标定位
                    toR.X      = 0;
                    toR.Y      = 0;
                    toR.Width  = initImage.Width;
                    toR.Height = (int)System.Math.Floor(initImage.Width / templateRate);
                }
                //高为标准进行裁剪
                else
                {
                    pickedImage = new System.Drawing.Bitmap((int)System.Math.Floor(initImage.Height * templateRate), initImage.Height);
                    pickedG     = System.Drawing.Graphics.FromImage(pickedImage);

                    fromR.X      = (int)System.Math.Floor((initImage.Width - initImage.Height * templateRate) / 2);
                    fromR.Y      = 0;
                    fromR.Width  = (int)System.Math.Floor(initImage.Height * templateRate);
                    fromR.Height = initImage.Height;

                    toR.X      = 0;
                    toR.Y      = 0;
                    toR.Width  = (int)System.Math.Floor(initImage.Height * templateRate);
                    toR.Height = initImage.Height;
                }

                //设置质量
                pickedG.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.HighQualityBicubic;
                pickedG.SmoothingMode     = System.Drawing.Drawing2D.SmoothingMode.HighQuality;

                //裁剪
                pickedG.DrawImage(initImage, toR, fromR, System.Drawing.GraphicsUnit.Pixel);

                //按模版大小生成最终图片
                System.Drawing.Image    templateImage = new System.Drawing.Bitmap(maxWidth, maxHeight);
                System.Drawing.Graphics templateG     = System.Drawing.Graphics.FromImage(templateImage);
                templateG.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.High;
                templateG.SmoothingMode     = System.Drawing.Drawing2D.SmoothingMode.HighQuality;
                templateG.Clear(Color.White);
                templateG.DrawImage(pickedImage, new System.Drawing.Rectangle(0, 0, maxWidth, maxHeight), new System.Drawing.Rectangle(0, 0, pickedImage.Width, pickedImage.Height), System.Drawing.GraphicsUnit.Pixel);

                //关键质量控制
                //获取系统编码类型数组,包含了jpeg,bmp,png,gif,tiff
                ImageCodecInfo    ici = SunImgFormat.GetImageCodecInfo(imgExt);
                EncoderParameters ep  = new EncoderParameters(1);
                ep.Param[0] = new EncoderParameter(System.Drawing.Imaging.Encoder.Quality, (long)quality);
                //保存缩略图
                templateImage.Save(newMS, ici, ep);
                //templateImage.Save(fileSaveUrl, System.Drawing.Imaging.ImageFormat.Jpeg);

                //释放资源
                ep.Dispose();
                templateG.Dispose();
                templateImage.Dispose();

                pickedG.Dispose();
                pickedImage.Dispose();
            }

            //释放资源
            initImage.Dispose();
            return(newMS);
        }
예제 #6
0
        /// <summary>
        /// 加图片水印
        /// </summary>
        /// <param name="sourceImgMS">要加水印的原图(System.Drawing)</param>
        /// <param name="watermarkImg">水印文件名</param>
        /// <param name="watermarkStatus">图片水印位置1=左上 2=中上 3=右上 4=左中  5=中中 6=右中 7=左下 8=右中 9=右下</param>
        /// <param name="quality">加水印后的质量0~100,数字越大质量越高</param>
        /// <param name="watermarkTransparency">水印图片的透明度1~10,数字越小越透明,10为不透明</param>
        ///<param name="imgExt">图片后缀</param>
        public static MemoryStream ImageWaterMarkPic(MemoryStream sourceImgMS, MemoryStream watermarkImg, int watermarkStatus, int quality, int watermarkTransparency, string imgExt)
        {
            Image       sourceImg = Image.FromStream(sourceImgMS);  //原图
            Image       watermark = Image.FromStream(watermarkImg); //水印图
            ImageFormat tFormat   = sourceImg.RawFormat;            //获取原图格式
            Graphics    g         = Graphics.FromImage(sourceImg);

            //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;

            if (watermark.Height >= sourceImg.Height || watermark.Width >= sourceImg.Width)
            {
                throw new Exception("水印图片大于原图");
            }

            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 transparency = 0.5F;

            if (watermarkTransparency >= 1 && watermarkTransparency <= 10)
            {
                transparency = (watermarkTransparency / 10.0F);
            }


            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, transparency, 0.0f },
                new float[] { 0.0f, 0.0f, 0.0f,         0.0f, 1.0f }
            };

            ColorMatrix colorMatrix = new ColorMatrix(colorMatrixElements);

            imageAttributes.SetColorMatrix(colorMatrix, ColorMatrixFlag.Default, ColorAdjustType.Bitmap);

            int xpos = 0;
            int ypos = 0;

            switch (watermarkStatus)
            {
            case 1:
                xpos = (int)(sourceImg.Width * (float).01);
                ypos = (int)(sourceImg.Height * (float).01);
                break;

            case 2:
                xpos = (int)((sourceImg.Width * (float).50) - (watermark.Width / 2));
                ypos = (int)(sourceImg.Height * (float).01);
                break;

            case 3:
                xpos = (int)((sourceImg.Width * (float).99) - (watermark.Width));
                ypos = (int)(sourceImg.Height * (float).01);
                break;

            case 4:
                xpos = (int)(sourceImg.Width * (float).01);
                ypos = (int)((sourceImg.Height * (float).50) - (watermark.Height / 2));
                break;

            case 5:
                xpos = (int)((sourceImg.Width * (float).50) - (watermark.Width / 2));
                ypos = (int)((sourceImg.Height * (float).50) - (watermark.Height / 2));
                break;

            case 6:
                xpos = (int)((sourceImg.Width * (float).99) - (watermark.Width));
                ypos = (int)((sourceImg.Height * (float).50) - (watermark.Height / 2));
                break;

            case 7:
                xpos = (int)(sourceImg.Width * (float).01);
                ypos = (int)((sourceImg.Height * (float).99) - watermark.Height);
                break;

            case 8:
                xpos = (int)((sourceImg.Width * (float).50) - (watermark.Width / 2));
                ypos = (int)((sourceImg.Height * (float).99) - watermark.Height);
                break;

            case 9:
                xpos = (int)((sourceImg.Width * (float).99) - (watermark.Width));
                ypos = (int)((sourceImg.Height * (float).99) - watermark.Height);
                break;
            }

            g.DrawImage(watermark, new Rectangle(xpos, ypos, watermark.Width, watermark.Height), 0, 0, watermark.Width, watermark.Height, GraphicsUnit.Pixel, imageAttributes);

            ImageCodecInfo    ici           = SunImgFormat.GetImageCodecInfo(imgExt);
            EncoderParameters encoderParams = new EncoderParameters();

            long[] qualityParam = new long[1];
            if (quality < 0 || quality > 100)
            {
                quality = 80;
            }

            qualityParam[0] = quality;

            EncoderParameter encoderParam = new EncoderParameter(System.Drawing.Imaging.Encoder.Quality, qualityParam);

            encoderParams.Param[0] = encoderParam;
            MemoryStream newMS = new MemoryStream();

            if (ici != null)
            {
                sourceImg.Save(newMS, ici, encoderParams);
            }
            else
            {
                sourceImg.Save(newMS, tFormat);
            }

            watermarkImg.Dispose(); //释放资源
            sourceImgMS.Dispose();  //释放资源
            g.Dispose();
            sourceImg.Dispose();
            watermark.Dispose();
            imageAttributes.Dispose();
            return(newMS);
        }
예제 #7
0
        /// <summary>
        /// 增加图片文字水印
        /// </summary>
        /// <param name="sourceImgMS">要加水印的原图(System.Drawing)</param>
        /// <param name="watermarkText">水印文字</param>
        /// <param name="watermarkStatus">图片水印位置1=左上 2=中上 3=右上 4=左中  5=中中 6=右中 7=左下 8=右中 9=右下</param>
        /// <param name="quality">加水印后的质量0~100,数字越大质量越高</param>
        /// <param name="fontname">水印的字体</param>
        /// <param name="fontsize">水印的字号</param>
        ///<param name="imgExt">图片后缀</param>
        public static MemoryStream ImageWaterMarkText(MemoryStream sourceImgMS, string watermarkText, int watermarkStatus, int quality, string fontname, int fontsize, Color color, string imgExt)
        {
            Image       img      = Image.FromStream(sourceImgMS);
            ImageFormat sFormat  = img.RawFormat;//获取原图格式
            Graphics    g        = Graphics.FromImage(img);
            Font        drawFont = new Font(fontname, fontsize, FontStyle.Regular, GraphicsUnit.Pixel);
            SizeF       crSize;

            crSize = g.MeasureString(watermarkText, drawFont);

            float xpos = 0;
            float ypos = 0;

            switch (watermarkStatus)
            {
            case 1:
                xpos = (float)img.Width * (float).01;
                ypos = (float)img.Height * (float).01;
                break;

            case 2:
                xpos = ((float)img.Width * (float).50) - (crSize.Width / 2);
                ypos = (float)img.Height * (float).01;
                break;

            case 3:
                xpos = ((float)img.Width * (float).99) - crSize.Width;
                ypos = (float)img.Height * (float).01;
                break;

            case 4:
                xpos = (float)img.Width * (float).01;
                ypos = ((float)img.Height * (float).50) - (crSize.Height / 2);
                break;

            case 5:
                xpos = ((float)img.Width * (float).50) - (crSize.Width / 2);
                ypos = ((float)img.Height * (float).50) - (crSize.Height / 2);
                break;

            case 6:
                xpos = ((float)img.Width * (float).99) - crSize.Width;
                ypos = ((float)img.Height * (float).50) - (crSize.Height / 2);
                break;

            case 7:
                xpos = (float)img.Width * (float).01;
                ypos = ((float)img.Height * (float).99) - crSize.Height;
                break;

            case 8:
                xpos = ((float)img.Width * (float).50) - (crSize.Width / 2);
                ypos = ((float)img.Height * (float).99) - crSize.Height;
                break;

            case 9:
                xpos = ((float)img.Width * (float).99) - crSize.Width;
                ypos = ((float)img.Height * (float).99) - crSize.Height;
                break;
            }
            //g.DrawString(watermarkText, drawFont, new SolidBrush(Color.White), xpos + 1, ypos + 1);文字阴影
            g.DrawString(watermarkText, drawFont, new SolidBrush(color), xpos, ypos);
            ImageCodecInfo    ici           = SunImgFormat.GetImageCodecInfo(imgExt);
            EncoderParameters encoderParams = new EncoderParameters();

            long[] qualityParam = new long[1];
            if (quality < 0 || quality > 100)
            {
                quality = 80;
            }

            qualityParam[0] = quality;

            EncoderParameter encoderParam = new EncoderParameter(System.Drawing.Imaging.Encoder.Quality, qualityParam);

            encoderParams.Param[0] = encoderParam;
            MemoryStream newMs = new MemoryStream();

            if (ici != null)
            {
                img.Save(newMs, ici, encoderParams);
            }
            else
            {
                img.Save(newMs, sFormat);
            }
            sourceImgMS.Dispose();
            g.Dispose();
            img.Dispose();
            return(newMs);
        }