利用GDI+分割图片，在图片上加字

System.Drawing.Image img;
            System.Drawing.Graphics g;
            System.Drawing.Bitmap bmp;
        
            img=System.Drawing.Image.FromFile(filename);

            if(img.Width!=768 ||img.Height!=928)
                return "";
            if(!BakFilePath.Equals("nobak") && !File.Exists(this.BakFilePath+Path.GetFileName(filename))  )
                File.Copy(filename,this.BakFilePath+Path.GetFileName(filename));
            bmp=new Bitmap(1536,304,System.Drawing.Imaging.PixelFormat.Format24bppRgb);
            g=System.Drawing.Graphics.FromImage(bmp);            
            g.DrawImage(img,0,0,new Rectangle(0,608,768,304),GraphicsUnit.Pixel);//取第三张
            
            g.DrawImage(img,768,0,new Rectangle(0,304,768,304),GraphicsUnit.Pixel);//第一张
            
            /**//*************************加字*******************************/        
            SolidBrush drawBrush = new SolidBrush(Color.Red); 
            Font drawFont = new Font("Arial", 4, FontStyle.Regular, GraphicsUnit.Millimeter); 
            float xPos = 550; 
            float yPos = 0; 
            
            decimal Speed,SpeedP;        
            Speed=decimal.Parse(PicConvert.LoadConfig("Speed"));
            SpeedP =decimal.Parse(PicConvert.LoadConfig("SpeedP"));
            //g.DrawString("限速"+Speed+"公里/小时 超速百分比:"+SpeedP+"%", drawFont, drawBrush, xPos, yPos); 
            g.DrawString("限速:"+Speed+"公里 超速:"+SpeedP+" %", drawFont, drawBrush, xPos, yPos); 
//            newbmp=new Bitmap(bmp,1536,592);
            /**//*************************加字*******************************/

/**//*********************************************************************/
//            ImageCodecInfo[]  codecs=ImageCodecInfo.GetImageEncoders();    
//        
//            ImageCodecInfo  ici=null;  
//            foreach(ImageCodecInfo  codec  in  codecs)  
//            {  
//                if(codec.MimeType=="image/jpeg")  
//                    ici=codec;  
//            }  
//            
//            EncoderParameters  ep=new  EncoderParameters();  
//            ep.Param[0]=new  EncoderParameter(Encoder.Quality,(long)25);  
//            newbmp.Save(this.DesFilePath+@"\"+newfilename,ici,ep);    


            Bitmap myBitmap;
            ImageCodecInfo myImageCodecInfo;
            Encoder myEncoder;
            EncoderParameter myEncoderParameter;
            EncoderParameters myEncoderParameters;
            // Create a Bitmap object based on a BMP file.
            myBitmap = new Bitmap(bmp,1536,592);
            // Get an ImageCodecInfo object that represents the JPEG codec.
            myImageCodecInfo = GetEncoderInfo("image/jpeg");
            // Create an Encoder object based on the GUID
            // for the Quality parameter category.
            myEncoder = Encoder.Quality;
            // Create an EncoderParameters object.
            // An EncoderParameters object has an array of EncoderParameter
            // objects. In this case, there is only one
            // EncoderParameter object in the array.
            myEncoderParameters = new EncoderParameters(1);
            // Save the bitmap as a JPEG file with quality level 25.
            myEncoderParameter = new EncoderParameter(myEncoder, 40L);
            myEncoderParameters.Param[0] = myEncoderParameter;
            myBitmap.Save(this.DesFilePath+@"\"+newfilename, myImageCodecInfo, myEncoderParameters);
//            // Save the bitmap as a JPEG file with quality level 50.
//            myEncoderParameter = new EncoderParameter(myEncoder, 50L);
//            myEncoderParameters.Param[0] = myEncoderParameter;
//            myBitmap.Save(this.DesFilePath+@"\"+"Shapes050"+newfilename, myImageCodecInfo, myEncoderParameters);
//            // Save the bitmap as a JPEG file with quality level 75.
//            myEncoderParameter = new EncoderParameter(myEncoder, 75L);
//            myEncoderParameters.Param[0] = myEncoderParameter;
//            myBitmap.Save(this.DesFilePath+@"\"+"Shapes075"+newfilename, myImageCodecInfo, myEncoderParameters);

            /**//*****************************************************/
            //newbmp.Save(this.DesFilePath+@"\"+newfilename,System.Drawing.Imaging.ImageFormat.Jpeg);    
            myBitmap.Dispose();
            bmp.Dispose();
            g.Dispose();
            img.Dispose();
            File.Delete(filename);
            return newfilename;